diff --git a/.cargo/config.toml b/.cargo/config.toml new file mode 100644 index 0000000..0953166 --- /dev/null +++ b/.cargo/config.toml @@ -0,0 +1,6 @@ +[build] +target = "targets/i686.json" + +[unstable] +build-std = ["core"] +build-std-features = ["compiler-builtins-mem"] diff --git a/.gdbinit.tmpl b/.gdbinit.tmpl index f71681a..ca8444b 100644 --- a/.gdbinit.tmpl +++ b/.gdbinit.tmpl @@ -25,3 +25,4 @@ target remote localhost:1234 echo + symbol-file kernel\n symbol-file kernel +# layout split \ No newline at end of file diff --git a/Cargo.toml b/Cargo.toml index 2dd5beb..a5f3964 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -2,6 +2,7 @@ name = "xv6" version = "0.1.0" edition = "2021" +autobins = false [lib] name = "kernel" @@ -15,4 +16,4 @@ modular-bitfield = "0.11.2" panic="abort" opt-level = "s" # Optimize for size codegen-units = 1 # Fewer units for better cross-function inlining -lto = true # Link-time optimization \ No newline at end of file +lto = true # Enabled Link-time optimization diff --git a/Makefile b/Makefile index fa7b33b..fd3dcae 100644 --- a/Makefile +++ b/Makefile @@ -1,33 +1,26 @@ -OBJS = entry.o vectors.o trapasm.o +OBJS = entry.o vectors.o trapasm.o swtch.o RS = src/*.rs # Cross-compiling (e.g., on Mac OS X) #TOOLPREFIX = i386-jos-elf -#TOOLPREFIX = i386-elf- +# TOOLPREFIX = i686-elf- # Using native tools (e.g., on X86 Linux) -#TOOLPREFIX = +#TOOLPREFIX = # Try to infer the correct TOOLPREFIX if not set ifndef TOOLPREFIX -TOOLPREFIX := $(shell if i386-jos-elf-objdump -i 2>&1 | grep '^elf32-i386$$' >/dev/null 2>&1; \ +TOOLPREFIX := $(shell if command -v i386-jos-elf-gcc >/dev/null 2>&1 && i386-jos-elf-objdump -i 2>&1 | grep '^elf32-i386$$' >/dev/null 2>&1; \ then echo 'i386-jos-elf-'; \ - elif objdump -i 2>&1 | grep 'elf32-i386' >/dev/null 2>&1; \ + elif command -v i686-elf-gcc >/dev/null 2>&1 && i686-elf-objdump -i 2>&1 | grep 'elf32-i386' >/dev/null 2>&1; \ + then echo 'i686-elf-'; \ + elif command -v gcc >/dev/null 2>&1 && objdump -i 2>&1 | grep 'elf32-i386' >/dev/null 2>&1; \ then echo ''; \ else echo "***" 1>&2; \ echo "*** Error: Couldn't find an i386-*-elf version of GCC/binutils." 1>&2; \ - echo "*** Is the directory with i386-jos-elf-gcc in your PATH?" 1>&2; \ - echo "*** If your i386-*-elf toolchain is installed with a command" 1>&2; \ - echo "*** prefix other than 'i386-jos-elf-', set your TOOLPREFIX" 1>&2; \ - echo "*** environment variable to that prefix and run 'make' again." 1>&2; \ - echo "*** To turn off this error, run 'gmake TOOLPREFIX= ...'." 1>&2; \ - echo "***" 1>&2; exit 1; fi) + exit 1; fi) endif -# If the makefile can't find QEMU, specify its path here -# QEMU = qemu-system-i386 - -# Try to infer the correct QEMU ifndef QEMU QEMU = $(shell if which qemu > /dev/null; \ then echo qemu; exit; \ @@ -35,14 +28,7 @@ QEMU = $(shell if which qemu > /dev/null; \ then echo qemu-system-i386; exit; \ elif which qemu-system-x86_64 > /dev/null; \ then echo qemu-system-x86_64; exit; \ - else \ - qemu=/Applications/Q.app/Contents/MacOS/i386-softmmu.app/Contents/MacOS/i386-softmmu; \ - if test -x $$qemu; then echo $$qemu; exit; fi; fi; \ - echo "***" 1>&2; \ - echo "*** Error: Couldn't find a working QEMU executable." 1>&2; \ - echo "*** Is the directory containing the qemu binary in your PATH" 1>&2; \ - echo "*** or have you tried setting the QEMU variable in Makefile?" 1>&2; \ - echo "***" 1>&2; exit 1) + else echo "*** Error: Couldn't find QEMU." 1>&2; exit 1; fi) endif CC = $(TOOLPREFIX)gcc @@ -50,13 +36,13 @@ AS = $(TOOLPREFIX)gas LD = $(TOOLPREFIX)ld OBJCOPY = $(TOOLPREFIX)objcopy OBJDUMP = $(TOOLPREFIX)objdump + CFLAGS = -fno-pic -static -fno-builtin -fno-strict-aliasing -O2 -Wall -MD -ggdb -m32 -Werror -fno-omit-frame-pointer CFLAGS += $(shell $(CC) -fno-stack-protector -E -x c /dev/null >/dev/null 2>&1 && echo -fno-stack-protector) + ASFLAGS = -m32 -gdwarf-2 -Wa,-divide -# FreeBSD ld wants ``elf_i386_fbsd'' LDFLAGS += -m $(shell $(LD) -V | grep elf_i386 2>/dev/null | head -n 1) -# Disable PIE when possible (for Ubuntu 16.10 toolchain) ifneq ($(shell $(CC) -dumpspecs 2>/dev/null | grep -e '[^f]no-pie'),) CFLAGS += -fno-pie -no-pie endif @@ -64,30 +50,50 @@ ifneq ($(shell $(CC) -dumpspecs 2>/dev/null | grep -e '[^f]nopie'),) CFLAGS += -fno-pie -nopie endif +# Disk image with bootblock + kernel xv6.img: bootblock kernel dd if=/dev/zero of=xv6.img count=10000 dd if=bootblock of=xv6.img conv=notrunc dd if=kernel of=xv6.img seek=1 conv=notrunc -bootblock: bootasm.S bootmain.c +# Build mkfs utility and create filesystem image +mkfs: src/mkfs.rs + rustc -W warnings -o mkfs src/mkfs.rs + +fs.img: mkfs *.txt + ./mkfs fs.img *.txt + +bootblock: bootasm.S bootmain.c linkers/bootblock.ld $(CC) $(CFLAGS) -fno-pic -O -nostdinc -I. -c bootmain.c $(CC) $(CFLAGS) -fno-pic -nostdinc -I. -c bootasm.S - $(LD) $(LDFLAGS) -N -e start -Ttext 0x7C00 -o bootblock.o bootasm.o bootmain.o - $(OBJDUMP) -S -D bootblock.o > bootblock.asm - $(OBJCOPY) -S -O binary -j .text bootblock.o bootblock - ./sign.pl bootblock + $(LD) $(LDFLAGS) -T linkers/bootblock.ld -o bootblock.o bootasm.o bootmain.o + $(OBJDUMP) -S bootblock.o > bootblock.asm + $(OBJCOPY) -S -O binary bootblock.o bootblock + +initcode: initcode.S + $(CC) $(CFLAGS) -nostdinc -I. -c initcode.S + $(LD) $(LDFLAGS) -N -e start -Ttext 0 -o initcode.out initcode.o + $(OBJCOPY) -S -O binary initcode.out initcode + $(OBJDUMP) -S initcode.o > initcode.asm kernel.a: $(RS) - cargo rustc -Z build-std=core -Z build-std-features=compiler-builtins-mem --target ./targets/i686.json --lib --release -- -A warnings --emit link=kernel.a + cargo build -Z build-std=core -Z build-std-features=compiler-builtins-mem -Z json-target-spec\ + --target ./targets/i686.json --release + @tdir=$$(cargo metadata --format-version=1 --no-deps | sed -n 's/.*"target_directory":"\([^"]*\)".*/\1/p'); \ + lib=$$(find "$$tdir" -maxdepth 4 -type f -name 'libkernel.a' | head -n 1); \ + if [ -z "$$lib" ]; then echo "ERROR: libkernel.a not found"; exit 1; fi; \ + cp "$$lib" kernel.a + -kernel: kernel.a $(OBJS) ./linkers/kernel.ld - ld -m elf_i386 -T ./linkers/kernel.ld -o kernel $(OBJS) kernel.a +kernel: kernel.a $(OBJS) ./linkers/kernel.ld initcode + $(LD) -m elf_i386 -T ./linkers/kernel.ld -o kernel $(OBJS) kernel.a -b binary initcode $(OBJDUMP) -S -D kernel > kernel.asm $(OBJDUMP) -t kernel | sed '1,/SYMBOL TABLE/d; s/ .* / /; /^$$/d' > kernel.sym vectors.S: vectors.pl ./vectors.pl > vectors.S + # $(LD) $(LDFLAGS) -T kernel.ld -o kernel entry.o kernel.a -b binary # ld -m elf_i386 -T kernel.ld -o kernel entry.o kernel.a -b binary # Prevent deletion of intermediate files, e.g. cat.o, after first build, so @@ -95,35 +101,34 @@ vectors.S: vectors.pl # details: # http://www.gnu.org/software/make/manual/html_node/Chained-Rules.html .PRECIOUS: %.o - -include *.d -clean: +clean: rm -f *.tex *.dvi *.idx *.aux *.log *.ind *.ilg \ - *.a *.o *.d *.asm *.sym bootblock kernel xv6.img .gdbinit vectors.S - rm -r target + *.a *.o *.d *.asm *.sym bootblock kernel xv6.img fs.img mkfs .gdbinit vectors.S + rm -rf target # run in emulators -# try to generate a unique GDB port GDBPORT = $(shell expr `id -u` % 5000 + 25000) -# QEMU's gdb stub command line changed in 0.11 QEMUGDB = $(shell if $(QEMU) -help | grep -q '^-gdb'; \ then echo "-gdb tcp::$(GDBPORT)"; \ else echo "-s -p $(GDBPORT)"; fi) + ifndef CPUS - CPUS := 1 +CPUS := 1 endif -# For debugging -# QEMUEXTRA = -no-reboot -d int,cpu_reset -QEMUOPTS = -drive file=xv6.img,index=0,media=disk,format=raw -smp $(CPUS) -m 512 $(QEMUEXTRA) +# Attach fs.img as disk1 (index=1), like the C version +QEMUOPTS = -drive file=xv6.img,index=0,media=disk,format=raw \ + -drive file=fs.img,index=1,media=disk,format=raw \ + -smp $(CPUS) -m 512 $(QEMUEXTRA) -qemu: xv6.img +qemu: xv6.img fs.img $(QEMU) -nographic $(QEMUOPTS) .gdbinit: .gdbinit.tmpl sed "s/localhost:1234/localhost:$(GDBPORT)/" < $^ > $@ -qemu-gdb: xv6.img .gdbinit +qemu-gdb: xv6.img .gdbinit fs.img @echo "*** Now run 'gdb'." 1>&2 - $(QEMU) -nographic $(QEMUOPTS) -S $(QEMUGDB) \ No newline at end of file + $(QEMU) -nographic $(QEMUOPTS) -S $(QEMUGDB) diff --git a/README b/README deleted file mode 100644 index 14ca193..0000000 --- a/README +++ /dev/null @@ -1,5 +0,0 @@ -For the COL331 course - - -1. The next step to make things look good is to remove perl script , and that may be done using a separate linker script. -2. Or may be use inclbin inside assembly. \ No newline at end of file diff --git a/README.md b/README.md new file mode 100644 index 0000000..dddf7be --- /dev/null +++ b/README.md @@ -0,0 +1 @@ +# col331rs: p12-file-layer (Rust) \ No newline at end of file diff --git a/bootasm.S b/bootasm.S index 81c0d52..26f81d0 100644 --- a/bootasm.S +++ b/bootasm.S @@ -83,4 +83,6 @@ gdt: gdtdesc: .word (gdtdesc - gdt - 1) # sizeof(gdt) - 1 - .long gdt # address gdt \ No newline at end of file + .long gdt # address gdt + +.section .note.GNU-stack,"",@progbits \ No newline at end of file diff --git a/entry.S b/entry.S index a7f6755..26000a2 100644 --- a/entry.S +++ b/entry.S @@ -48,3 +48,6 @@ entry: call entryofrust .comm stack, KSTACKSIZE + +# Add .note.GNU-stack section for non-executable stack marking +.section .note.GNU-stack,"",@progbits diff --git a/initcode.S b/initcode.S new file mode 100644 index 0000000..ea554dc --- /dev/null +++ b/initcode.S @@ -0,0 +1,10 @@ +# Initial process execs /init. +# This code runs in user space. + +# movl %eax, 0x10001 +# movl %eax, 0x1000100 +.globl start +start: + add $1, %eax + movl %eax, 0x10001 + jmp start diff --git a/linkers/bootblock.ld b/linkers/bootblock.ld new file mode 100644 index 0000000..6ac5c34 --- /dev/null +++ b/linkers/bootblock.ld @@ -0,0 +1,29 @@ +OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386") +OUTPUT_ARCH(i386) +ENTRY(start) + +SECTIONS +{ + . = 0x7c00; + + .text : { + *(.text .text.*) + } + + .rodata : { + *(.rodata .rodata.*) + } + + .data : { + *(.data .data.*) + } + + /DISCARD/ : { + *(.eh_frame .note.GNU-stack .comment) + } + + . = 0x7c00 + 510; + .signature : { + SHORT(0xaa55) + } +} diff --git a/linkers/kernel.ld b/linkers/kernel.ld index cf6630e..0b70493 100644 --- a/linkers/kernel.ld +++ b/linkers/kernel.ld @@ -8,7 +8,7 @@ ENTRY(_start) SECTIONS { /* Link the kernel at this address: "." means the current address */ - /* Must be equal to KERNLINK */ + /* Must be equal to KERNLINK */ . = 0x00100000; .text : AT(0x100000) { diff --git a/rust-toolchain.toml b/rust-toolchain.toml index 5d56faf..87b5402 100644 --- a/rust-toolchain.toml +++ b/rust-toolchain.toml @@ -1,2 +1,3 @@ [toolchain] channel = "nightly" +components = ["rust-src"] \ No newline at end of file diff --git a/src/bio.rs b/src/bio.rs new file mode 100644 index 0000000..30e6d81 --- /dev/null +++ b/src/bio.rs @@ -0,0 +1,148 @@ +use core::sync::atomic::Ordering; + +use crate::buf::{Buf, B_DIRTY, B_VALID, NBUF}; + +const HEAD: usize = NBUF; // sentinel index + +struct BCache { + buf: [Buf; NBUF], + head_prev: usize, + head_next: usize, +} + +impl BCache { + pub const fn new() -> Self { + Self { + buf: [const { Buf::new() }; NBUF], + head_prev: HEAD, + head_next: HEAD, + } + } +} + +static mut BCACHE: BCache = BCache::new(); + +pub fn binit() { + unsafe { + // empty list + BCACHE.head_prev = HEAD; + BCACHE.head_next = HEAD; + + // insert all buffers at head (MRU side) + for i in 0..NBUF { + insert_at_head(i); + } + } +} + +#[inline] +fn insert_at_head(i: usize) { + unsafe { + let first = BCACHE.head_next; + + BCACHE.buf[i].prev = HEAD; + BCACHE.buf[i].next = first; + + if first == HEAD { + // list was empty + BCACHE.head_prev = i; + } else { + BCACHE.buf[first].prev = i; + } + + BCACHE.head_next = i; + } +} + +#[inline] +fn remove_from_list(i: usize) { + unsafe { + let prev = BCACHE.buf[i].prev; + let next = BCACHE.buf[i].next; + + if prev == HEAD { + BCACHE.head_next = next; + } else { + BCACHE.buf[prev].next = next; + } + + if next == HEAD { + BCACHE.head_prev = prev; + } else { + BCACHE.buf[next].prev = prev; + } + } +} + +// Return mutable buf by index. +// Safe to call only when you “own” the buffer logically (like xv6 “locked buf”). +pub fn buf_mut(idx: usize) -> &'static mut Buf { + unsafe { &mut BCACHE.buf[idx] } +} + +// Look for cached block; else recycle an unused non-dirty buffer. +fn bget(dev: u32, blockno: u32) -> usize { + unsafe { + // Is the block already cached? + let mut b = BCACHE.head_next; + while b != HEAD { + if BCACHE.buf[b].dev == dev && BCACHE.buf[b].blockno == blockno { + BCACHE.buf[b].refcnt += 1; + return b; + } + b = BCACHE.buf[b].next; + } + + // Not cached; recycle from LRU end. + let mut b = BCACHE.head_prev; + while b != HEAD { + let flags = BCACHE.buf[b].flags.load(Ordering::Acquire); + if BCACHE.buf[b].refcnt == 0 && (flags & B_DIRTY) == 0 { + BCACHE.buf[b].dev = dev; + BCACHE.buf[b].blockno = blockno; + BCACHE.buf[b].flags.store(0, Ordering::Release); + BCACHE.buf[b].refcnt = 1; + BCACHE.buf[b].qnext = None; + return b; + } + b = BCACHE.buf[b].prev; + } + + panic!("bget: no buffers"); + } +} + +// Return buffer index with contents of block. +pub fn bread(dev: u32, blockno: u32) -> usize { + let idx = bget(dev, blockno); + + let flags = buf_mut(idx).flags.load(Ordering::Acquire); + if (flags & B_VALID) == 0 { + crate::ide::iderw(idx); + } + + idx +} + +// Mark dirty + write to disk. +pub fn bwrite(idx: usize) { + let b = buf_mut(idx); + b.flags.fetch_or(B_DIRTY, Ordering::AcqRel); + crate::ide::iderw(idx); +} + +// Release buffer. If refcnt hits 0, move to MRU head. +pub fn brelse(idx: usize) { + unsafe { + let b = &mut BCACHE.buf[idx]; + if b.refcnt == 0 { + panic!("brelse: refcnt underflow"); + } + + b.refcnt -= 1; + if b.refcnt == 0 { + remove_from_list(idx); + insert_at_head(idx); + } + } +} \ No newline at end of file diff --git a/src/buf.rs b/src/buf.rs new file mode 100644 index 0000000..75d0792 --- /dev/null +++ b/src/buf.rs @@ -0,0 +1,41 @@ +use core::sync::atomic::AtomicU32; + +// Re-export filesystem constants from constants.rs for convenience +// (other modules currently import BSIZE and NBUF from buf) +pub use crate::constants::{BSIZE, NBUF}; + +// Buffer flags +pub const B_VALID: u32 = 0x2; // buffer has been read from disk +pub const B_DIRTY: u32 = 0x4; // buffer needs to be written to disk + +#[repr(C)] +pub struct Buf { + pub flags: AtomicU32, + pub dev: u32, + pub blockno: u32, + pub refcnt: u32, + + // LRU list (intrusive, by index) + pub prev: usize, + pub next: usize, + + // disk queue (by index) + pub qnext: Option, + + pub data: [u8; BSIZE], +} + +impl Buf { + pub const fn new() -> Self { + Self { + flags: AtomicU32::new(0), + dev: 0, + blockno: 0, + refcnt: 0, + prev: 0, + next: 0, + qnext: None, + data: [0; BSIZE], + } + } +} \ No newline at end of file diff --git a/src/console.rs b/src/console.rs index 0f62712..c97c7a0 100644 --- a/src/console.rs +++ b/src/console.rs @@ -1,24 +1,153 @@ -use crate::uart::*; +use crate::{uart::*}; use core::fmt::*; +use crate::file::DEVSW; +use crate::param::CONSOLE; pub struct Console {} impl Write for Console { fn write_str(&mut self, s: &str) -> Result { for c in s.chars() { - consputc(c); + consputc(c as i32); } Ok(()) } } -const BACKSPACE: char = '\x08'; +const BACKSPACE: i32 = 0x100; +const INPUT_BUF: usize = 128; +const CTRL_D: i32 = C('D'); -fn consputc(c: char) { +#[allow(non_snake_case)] +const fn C(c: char) -> i32 { + (c as i32) - ('@' as i32) +} + +#[derive(Clone, Copy)] +struct Input { + buf: [u8; INPUT_BUF], + r: usize, + w: usize, + e: usize, +} + +static mut INPUT: Input = Input { + buf: [0; INPUT_BUF], + r: 0, + w: 0, + e: 0, +}; + +pub fn consputc(c: i32) { if c == BACKSPACE { - uartputc(BACKSPACE); - uartputc(' '); - uartputc(BACKSPACE); + uartputc('\x08' as i32); + uartputc(' ' as i32); + uartputc('\x08' as i32); } else { uartputc(c); } -} \ No newline at end of file +} + +pub fn consoleintr(getc: fn() -> i32) { + let mut doprocdump = false; + loop { + let c = getc(); + if c < 0 { + break; + } + + unsafe { + let input = &raw mut INPUT; + match c { + x if x == C('P') => { + // procdump() may indirectly use console output; call after loop + doprocdump = true; + } + x if x == C('U') => { + while (*input).e != (*input).w && (*input).buf[((*input).e - 1) % INPUT_BUF] != b'\n' { + (*input).e -= 1; + consputc(BACKSPACE); + } + } + x if x == C('H') || x == 0x7f => { + if (*input).e != (*input).w { + (*input).e -= 1; + consputc(BACKSPACE); + } + } + _ => { + if c != 0 && (*input).e.wrapping_sub((*input).r) < INPUT_BUF { + let c = if c == '\r' as i32 { '\n' as i32 } else { c }; + (*input).buf[(*input).e % INPUT_BUF] = c as u8; + (*input).e += 1; + consputc(c); + if c == '\n' as i32 || c == CTRL_D || (*input).e == (*input).r + INPUT_BUF { + // call myproc with the buf + (*input).w = (*input).e; + } + } + } + } + } + } + if doprocdump { + crate::proc::procdump(); + } +} + +pub fn consoleread(_ip: usize, dst: &mut [u8], n: i32) -> i32 { + let target = n; + let mut n = n; + + unsafe { + let input = &raw mut INPUT; + while n > 0 { + // Busy wait for input - mirrors C: while(input.r == input.w); + while core::ptr::read_volatile(&(*input).r) == core::ptr::read_volatile(&(*input).w) { + // Spin-wait (busy wait) for input to arrive + core::hint::spin_loop(); + } + + // Read character and increment read pointer - mirrors C: input.buf[input.r++ % INPUT_BUF] + let c = (*input).buf[(*input).r % INPUT_BUF] as i32; + (*input).r += 1; + + // Handle EOF (Ctrl-D) + if c == CTRL_D { + if n < target { + // Save ^D for next time, to make sure + // caller gets a 0-byte result. + (*input).r -= 1; + } + break; + } + + // Copy character to destination - mirrors C: *dst++ = c; + dst[(target - n) as usize] = c as u8; + n -= 1; + + // Break on newline + if c == '\n' as i32 { + break; + } + } + } + + target - n +} + +pub fn consolewrite(_ip: usize, src: &[u8], n: i32) -> i32 { + // Mirrors C: for(i = 0; i < n; i++) consputc(buf[i] & 0xff); + for i in 0..n { + consputc(src[i as usize] as i32); + } + n +} + +pub fn consoleinit() { + // Register console device handlers in the device switch table + // Mirrors C: devsw[CONSOLE].write = consolewrite; devsw[CONSOLE].read = consoleread; + unsafe { + DEVSW[CONSOLE].read = Some(consoleread); + DEVSW[CONSOLE].write = Some(consolewrite); + } +} diff --git a/src/constants.rs b/src/constants.rs index d06b826..75a41df 100644 --- a/src/constants.rs +++ b/src/constants.rs @@ -12,16 +12,54 @@ pub const SEG_UCODE: u16 = 3; // user code pub const SEG_UDATA: u16 = 4; // user data+stack pub const SEG_TSS: u16 = 5; // this process's task state +// cpu->gdt[NSEGS] holds the above segments. +pub const NSEGS: usize = 6; + +// Privilege level +pub const DPL_USER: u8 = 0x3; // User DPL + +// Application segment type bits +pub const STA_X: u8 = 0x8; // Executable segment +pub const STA_W: u8 = 0x2; // Writeable (non-executable segments) +pub const STA_R: u8 = 0x2; // Readable (executable segments) + +// Memory layout +pub const EXTMEM: u32 = 0x100000; // Start of extended memory +pub const PHYSTART: u32 = EXTMEM + PROCSIZE; +pub const PHYSTOP: u32 = 0xE000000; // Top physical memory +pub const DEVSPACE: u32 = 0xFE000000; // Other devices are at high addresses + +// Key addresses for address space layout +pub const KERNBASE: u32 = 0x0; // First kernel virtual address +pub const KERNLINK: u32 = KERNBASE + EXTMEM; // Address where kernel is linked + +// We assume that kernel.asm can fit in first 2MB +pub const STARTPROC: u32 = 0x200000; // Start allocating process from here (2MB) +pub const PROCSIZE: u32 = 0x100; // 1MB is the size of each process (in multiple of 4KB) + +// Page table constants +pub const PGSIZE: u32 = PROCSIZE << 12; // Process allocation granularity in bytes +pub const NPDENTRIES: usize = 1024; // # directory entries per page directory +pub const NPTENTRIES: usize = 1024; // # PTEs per page table +pub const PTXSHIFT: u32 = 12; // offset of PTX in a linear address +pub const PDXSHIFT: u32 = 22; // offset of PDX in a linear address + +#[inline] +pub const fn pgroundup(sz: usize) -> usize { + (sz + PGSIZE as usize - 1) & !(PGSIZE as usize - 1) +} + +// Page table/directory entry flags +pub const PTE_P: u32 = 0x001; // Present +pub const PTE_W: u32 = 0x002; // Writeable +pub const PTE_U: u32 = 0x004; // User +pub const PTE_PS: u32 = 0x080; // Page Size + // System segment type bits pub const STS_T32A: u8 = 0x9; // Available 32-bit TSS pub const STS_IG32: u8 = 0xE; // 32-bit Interrupt Gate pub const STS_TG32: u8 = 0xF; // 32-bit Trap Gate - -// ----------------------------------------------------- CPU RELATED ---------------------------------------------- -pub const KSTACKSIZE: usize = 4096; // size of per-process kernel stack -pub const NCPU: usize = 8; // maximum number of CPUs - // ----------------------------------------------- TRAPS ------------------------------------------------------- // x86 trap and interrupt constants @@ -51,17 +89,14 @@ pub const T_SIMDERR: u32 = 19; // SIMD floating point error // processor defined exceptions or interrupt vectors pub const T_SYSCALL: u32 = 64; // system call pub const T_DEFAULT: u32 = 500; // catchall - -pub const T_IRQ0: u32 = 32; // IRQ 0 corresponds to int T_IRQ - +pub const T_IRQ0: u32 = 32; pub const IRQ_TIMER: u32 = 0; pub const IRQ_KBD: u32 = 1; pub const IRQ_COM1: u32 = 4; pub const IRQ_IDE: u32 = 14; pub const IRQ_ERROR: u32 = 19; pub const IRQ_SPURIOUS: u32 = 31; - - +pub const IDE_TRAP: u32 = T_IRQ0 + IRQ_IDE; // ------------------------------------------------------ MP RELATED ------------------------------------------------------- // Processor flags @@ -116,4 +151,44 @@ pub const X1: u32 = 0x0000000B; // divide counts by 1 pub const PERIODIC: u32 = 0x00020000; // Periodic // Error handling -pub const MASKED: u32 = 0x00010000; // Interrupt masked \ No newline at end of file +pub const MASKED: u32 = 0x00010000; // Interrupt masked + +// ------------------------------------------------------ FILE SYSTEM (fs.h) ---------------------------------------------- +// On-disk file system format constants +// Both the kernel and user programs (mkfs) use these definitions + +pub const ROOTINO: u32 = 1; // root i-number +pub const BSIZE: usize = 512; // block size + +// File structure +pub const NDIRECT: usize = 12; // number of direct block pointers +pub const NINDIRECT: usize = BSIZE / core::mem::size_of::(); // number of indirect block pointers (BSIZE / sizeof(uint)) +pub const MAXFILE: usize = NDIRECT + NINDIRECT; // max file size in blocks + +// Directory entry +pub const DIRSIZ: usize = 14; // directory name length +pub const DIRENT_SIZE: usize = 2 + DIRSIZ; // sizeof(struct dirent) = 2 bytes for uint16_t + 14 bytes for name + +// Inode calculations +// Note: In C these are macros. IPB = (BSIZE / sizeof(struct dinode)) +// For Rust: sizeof(dinode) = 2+2+2+2+4+(13*4) = 64 bytes +// So IPB = 512/64 = 8 inodes per block +pub const DINODE_SIZE: usize = 64; // sizeof(struct dinode) +pub const IPB: usize = BSIZE / DINODE_SIZE; // inodes per block + +// Bitmap calculations +pub const BPB: usize = BSIZE * 8; // bitmap bits per block + +// ------------------------------------------------------ SYSTEM PARAMETERS (param.h) ---------------------------------------------- +// System-wide parameters +pub const MAXOPBLOCKS: usize = 10; // max # of blocks any FS op writes +pub const NBUF: usize = MAXOPBLOCKS * 3; // size of disk block cache +pub const FSSIZE: u32 = 1000; // size of file system in blocks (C version: 1000, extended: 10000) +pub const NINODES: u32 = 200; // number of inodes in file system + +// ------------------------------------------------------ FILE TYPES (stat.h) ---------------------------------------------- +// File type constants for inode.type field + +pub const T_DIR: u16 = 1; // Directory +pub const T_FILE: u16 = 2; // File +pub const T_DEV: u16 = 3; // Device diff --git a/src/fcntl.rs b/src/fcntl.rs new file mode 100644 index 0000000..2e76613 --- /dev/null +++ b/src/fcntl.rs @@ -0,0 +1,4 @@ +pub const O_RDONLY: i32 = 0x000; +pub const O_WRONLY: i32 = 0x001; +pub const O_RDWR: i32 = 0x002; +pub const O_CREATE: i32 = 0x200; diff --git a/src/file.rs b/src/file.rs new file mode 100644 index 0000000..427448b --- /dev/null +++ b/src/file.rs @@ -0,0 +1,448 @@ +use core::str; + +use crate::buf::BSIZE; +use crate::constants::{T_DIR, T_FILE, T_DEV, DIRSIZ, DIRENT_SIZE}; +use crate::fcntl::{O_CREATE, O_RDONLY, O_RDWR, O_WRONLY}; +use crate::fs; +use crate::log; +use crate::param::{MAXOPBLOCKS, NFILE, NDEV}; + +// Device switch table entry +#[derive(Copy, Clone)] +pub struct Devsw { + pub read: Option i32>, + pub write: Option i32>, +} + +impl Devsw { + pub const fn new() -> Self { + Self { + read: None, + write: None, + } + } +} + +pub static mut DEVSW: [Devsw; NDEV] = [const { Devsw::new() }; NDEV]; + +#[derive(Copy, Clone, PartialEq, Eq)] +pub enum FileType { + None, + Inode, + Device, +} + +#[derive(Copy, Clone)] +pub struct File { + pub type_: FileType, + pub refcnt: i32, + pub readable: bool, + pub writable: bool, + pub ip: usize, + pub off: u32, +} + +impl File { + pub const fn new() -> Self { + Self { + type_: FileType::None, + refcnt: 0, + readable: false, + writable: false, + ip: 0, + off: 0, + } + } +} + +struct FTable { + file: [File; NFILE], +} + +impl FTable { + const fn new() -> Self { + Self { + file: [const { File::new() }; NFILE], + } + } +} + +static mut FTABLE: FTable = FTable::new(); + +fn dirsiz_to_str(name: &[u8; DIRSIZ]) -> &str { + let len = name.iter().position(|&b| b == 0).unwrap_or(DIRSIZ); + str::from_utf8(&name[..len]).unwrap_or("") +} + +pub fn fileinit() { + unsafe { + for i in 0..NFILE { + FTABLE.file[i] = File::new(); + } + } +} + +pub fn filealloc() -> Option { + unsafe { + for i in 0..NFILE { + if FTABLE.file[i].refcnt == 0 { + FTABLE.file[i].refcnt = 1; + return Some(i); + } + } + } + None +} + +pub fn filedup(f_idx: usize) -> usize { + unsafe { + if f_idx >= NFILE { + panic!("filedup: bad file index"); + } + if FTABLE.file[f_idx].refcnt < 1 { + panic!("filedup"); + } + FTABLE.file[f_idx].refcnt += 1; + } + f_idx +} + +pub fn fileclose(f_idx: usize) { + let ff: File; + unsafe { + if f_idx >= NFILE { + panic!("fileclose: bad file index"); + } + + let f = &mut FTABLE.file[f_idx]; + if f.refcnt < 1 { + panic!("fileclose"); + } + f.refcnt -= 1; + if f.refcnt > 0 { + return; + } + + ff = *f; + *f = File::new(); + } + + if ff.type_ == FileType::Inode { + log::begin_op(); + fs::iput(ff.ip); + log::end_op(); + } +} + +pub fn filestat(f_idx: usize, st: &mut fs::Stat) -> i32 { + let f: File; + unsafe { + if f_idx >= NFILE { + panic!("filestat: bad file index"); + } + f = FTABLE.file[f_idx]; + } + + if f.type_ == FileType::Inode { + fs::iread(f.ip); + fs::stati(f.ip, st); + return 0; + } + + -1 +} + +pub fn fileread(f_idx: usize, dst: &mut [u8], n: i32) -> i32 { + if n < 0 || (n as usize) > dst.len() { + return -1; + } + + let f: File; + unsafe { + if f_idx >= NFILE { + panic!("fileread: bad file index"); + } + f = FTABLE.file[f_idx]; + } + + if !f.readable { + return -1; + } + + if f.type_ == FileType::Inode { + fs::iread(f.ip); + let r = fs::readi(f.ip, dst, f.off, n as u32); + if r > 0 { + unsafe { + FTABLE.file[f_idx].off += r as u32; + } + } + return r; + } + + panic!("fileread"); +} + +pub fn filewrite(f_idx: usize, src: &[u8], n: i32) -> i32 { + if n < 0 || (n as usize) > src.len() { + return -1; + } + + let f: File; + unsafe { + if f_idx >= NFILE { + panic!("filewrite: bad file index"); + } + f = FTABLE.file[f_idx]; + } + + if !f.writable { + return -1; + } + + if f.type_ == FileType::Inode { + let max = (((MAXOPBLOCKS - 1 - 1 - 2) / 2) * BSIZE) as i32; + let mut i = 0i32; + + while i < n { + let mut n1 = n - i; + if n1 > max { + n1 = max; + } + + log::begin_op(); + fs::iread(f.ip); + let off = unsafe { FTABLE.file[f_idx].off }; + let r = fs::writei(f.ip, &src[i as usize..], off, n1 as u32); + if r > 0 { + unsafe { + FTABLE.file[f_idx].off += r as u32; + } + } + log::end_op(); + + if r < 0 { + break; + } + if r != n1 { + panic!("short filewrite"); + } + i += r; + } + + if i == n { + n + } else { + -1 + } + } else { + panic!("filewrite"); + } +} + +pub fn isdirempty(dp_idx: usize) -> bool { + fs::iread(dp_idx); + + let mut off = (2 * DIRENT_SIZE) as u32; + while off < fs::inode_size(dp_idx) { + let mut raw = [0u8; DIRENT_SIZE]; + if fs::readi(dp_idx, &mut raw, off, DIRENT_SIZE as u32) != DIRENT_SIZE as i32 { + panic!("isdirempty: readi"); + } + let de = fs::parse_dirent(&raw); + if de.inum != 0 { + return false; + } + off += DIRENT_SIZE as u32; + } + + true +} + +pub fn unlink(path: &str, name: &mut [u8; DIRSIZ]) -> i32 { + log::begin_op(); + + let dp = match fs::nameiparent(path, name) { + Some(idx) => idx, + None => { + log::end_op(); + return -1; + } + }; + + fs::iread(dp); + + let name_str = dirsiz_to_str(name); + + if name_str == "." || name_str == ".." { + fs::iput(dp); + log::end_op(); + return -1; + } + + let mut off = 0u32; + let ip = match fs::dirlookup(dp, name_str, Some(&mut off)) { + Some(idx) => idx, + None => { + fs::iput(dp); + log::end_op(); + return -1; + } + }; + + fs::iread(ip); + + if fs::inode_nlink(ip) < 1 { + panic!("unlink: nlink < 1"); + } + + if fs::inode_type(ip) == T_DIR && !isdirempty(ip) { + fs::iput(ip); + fs::iput(dp); + log::end_op(); + return -1; + } + + let de = [0u8; DIRENT_SIZE]; + if fs::writei(dp, &de, off, DIRENT_SIZE as u32) != DIRENT_SIZE as i32 { + panic!("unlink: writei"); + } + + if fs::inode_type(ip) == T_DIR { + fs::inode_dec_nlink(dp); + fs::iupdate(dp); + } + fs::iput(dp); + + fs::inode_dec_nlink(ip); + fs::iupdate(ip); + fs::iput(ip); + + log::end_op(); + 0 +} + +fn create(path: &str, type_: i16, major: i16, minor: i16) -> Option { + let mut name = [0u8; DIRSIZ]; + + let dp = fs::nameiparent(path, &mut name)?; + fs::iread(dp); + + let name_str = dirsiz_to_str(&name); + + if let Some(ip) = fs::dirlookup(dp, name_str, None) { + fs::iput(dp); + fs::iread(ip); + if (type_ as u16) == T_FILE && fs::inode_type(ip) == T_FILE { + return Some(ip); + } + fs::iput(ip); + return None; + } + + let ip = fs::ialloc(fs::inode_dev(dp), type_); + + fs::iread(ip); + fs::inode_set_meta(ip, major, minor, 1); + fs::iupdate(ip); + + if (type_ as u16) == T_DIR { + fs::inode_inc_nlink(dp); + fs::iupdate(dp); + + if fs::dirlink(ip, ".", fs::inode_inum(ip)) < 0 || fs::dirlink(ip, "..", fs::inode_inum(dp)) < 0 { + panic!("create dots"); + } + } + + if fs::dirlink(dp, name_str, fs::inode_inum(ip)) < 0 { + panic!("create: dirlink"); + } + + fs::iput(dp); + + Some(ip) +} + +pub fn open(path: &str, omode: i32) -> Option { + log::begin_op(); + + let ip = if (omode & O_CREATE) != 0 { + let ip = match create(path, T_FILE as i16, 0, 0) { + Some(ip) => ip, + None => { + log::end_op(); + return None; + } + }; + ip + } else { + let ip = match fs::namei(path) { + Some(ip) => ip, + None => { + log::end_op(); + return None; + } + }; + fs::iread(ip); + if fs::inode_type(ip) == T_DIR && omode != O_RDONLY { + fs::iput(ip); + log::end_op(); + return None; + } + ip + }; + + let f_idx = match filealloc() { + Some(idx) => idx, + None => { + fs::iput(ip); + log::end_op(); + return None; + } + }; + + unsafe { + let f = &mut FTABLE.file[f_idx]; + f.type_ = FileType::Inode; + f.ip = ip; + f.off = 0; + f.readable = (omode & O_WRONLY) == 0; + f.writable = (omode & O_WRONLY) != 0 || (omode & O_RDWR) != 0; + } + + log::end_op(); + Some(f_idx) +} + +pub fn mkdir(path: &str) -> i32 { + log::begin_op(); + + let ip = match create(path, T_DIR as i16, 0, 0) { + Some(ip) => ip, + None => { + log::end_op(); + return -1; + } + }; + + fs::iput(ip); + log::end_op(); + 0 +} + +pub fn mknod(path: &str, major: i16, minor: i16) -> i32 { + log::begin_op(); + + let ip = match create(path, T_DEV as i16, major, minor) { + Some(ip) => ip, + None => { + log::end_op(); + return -1; + } + }; + + fs::iput(ip); + log::end_op(); + 0 +} diff --git a/src/fs.rs b/src/fs.rs new file mode 100644 index 0000000..12dcf4c --- /dev/null +++ b/src/fs.rs @@ -0,0 +1,837 @@ +use core::cmp::min; + +use crate::bio; +use crate::buf::BSIZE; +use crate::log; +use crate::param::{NINODE, ROOTDEV, NDEV}; +use crate::println; +use crate::constants::{NDIRECT, NINDIRECT, DIRSIZ, DIRENT_SIZE, DINODE_SIZE, IPB, BPB, MAXFILE}; +use crate::constants::{ROOTINO, T_DEV}; +use crate::file::DEVSW; + +pub use crate::constants::T_DIR; + +#[derive(Copy, Clone)] +#[repr(C)] +pub struct Superblock { + pub size: u32, + pub nblocks: u32, + pub ninodes: u32, + pub nlog: u32, + pub logstart: u32, + pub inodestart: u32, + pub bmapstart: u32, +} + +impl Superblock { + pub const fn new() -> Self { + Self { + size: 0, + nblocks: 0, + ninodes: 0, + nlog: 0, + logstart: 0, + inodestart: 0, + bmapstart: 0, + } + } +} + +#[repr(C)] +pub struct Inode { + pub dev: u32, + pub inum: u32, + pub refcnt: i32, + pub valid: i32, + + pub type_: i16, + pub major: i16, + pub minor: i16, + pub nlink: i16, + pub size: u32, + pub addrs: [u32; NDIRECT + 1], +} + +impl Inode { + pub const fn new() -> Self { + Self { + dev: 0, + inum: 0, + refcnt: 0, + valid: 0, + type_: 0, + major: 0, + minor: 0, + nlink: 0, + size: 0, + addrs: [0; NDIRECT + 1], + } + } +} + +#[repr(C)] +pub struct Stat { + pub type_: i16, + pub dev: i32, + pub ino: u32, + pub nlink: i16, + pub size: u32, +} + +impl Stat { + pub const fn new() -> Self { + Self { + type_: 0, + dev: 0, + ino: 0, + nlink: 0, + size: 0, + } + } +} + +#[derive(Copy, Clone)] +#[repr(C)] +pub struct Dirent { + pub inum: u16, + pub name: [u8; DIRSIZ], +} + +impl Dirent { + pub const fn new() -> Self { + Self { + inum: 0, + name: [0; DIRSIZ], + } + } +} + +struct ICache { + inode: [Inode; NINODE], +} + +impl ICache { + const fn new() -> Self { + Self { + inode: [const { Inode::new() }; NINODE], + } + } +} + +static mut SB: Superblock = Superblock::new(); +static mut ICACHE: ICache = ICache::new(); + +#[inline] +fn read_u16_le(data: &[u8], off: usize) -> u16 { + u16::from_le_bytes([data[off], data[off + 1]]) +} + +#[inline] +fn read_i16_le(data: &[u8], off: usize) -> i16 { + i16::from_le_bytes([data[off], data[off + 1]]) +} + +#[inline] +fn read_u32_le(data: &[u8], off: usize) -> u32 { + u32::from_le_bytes([data[off], data[off + 1], data[off + 2], data[off + 3]]) +} + +#[inline] +fn write_u16_le(data: &mut [u8], off: usize, val: u16) { + data[off..off + 2].copy_from_slice(&val.to_le_bytes()); +} + +#[inline] +fn write_i16_le(data: &mut [u8], off: usize, val: i16) { + data[off..off + 2].copy_from_slice(&val.to_le_bytes()); +} + +#[inline] +fn write_u32_le(data: &mut [u8], off: usize, val: u32) { + data[off..off + 4].copy_from_slice(&val.to_le_bytes()); +} + +#[inline] +fn iblock(inum: u32, sb: &Superblock) -> u32 { + inum / (IPB as u32) + sb.inodestart +} + +#[inline] +fn bblock(b: u32, sb: &Superblock) -> u32 { + b / (BPB as u32) + sb.bmapstart +} + +#[inline] +fn name_to_dirsiz(name: &str) -> [u8; DIRSIZ] { + let mut out = [0u8; DIRSIZ]; + let bytes = name.as_bytes(); + let n = min(bytes.len(), DIRSIZ); + out[..n].copy_from_slice(&bytes[..n]); + out +} + +pub fn parse_dirent(raw: &[u8]) -> Dirent { + let mut de = Dirent::new(); + de.inum = read_u16_le(raw, 0); + de.name.copy_from_slice(&raw[2..2 + DIRSIZ]); + de +} + +pub fn readsb(dev: u32, sb: &mut Superblock) { + let bp = bio::bread(dev, 1); + let data = &bio::buf_mut(bp).data; + + sb.size = read_u32_le(data, 0); + sb.nblocks = read_u32_le(data, 4); + sb.ninodes = read_u32_le(data, 8); + sb.nlog = read_u32_le(data, 12); + sb.logstart = read_u32_le(data, 16); + sb.inodestart = read_u32_le(data, 20); + sb.bmapstart = read_u32_le(data, 24); + + bio::brelse(bp); +} + +pub fn iinit(dev: u32) { + unsafe { + readsb(dev, &mut *(&raw mut SB)); + let sb = &*(&raw const SB); + println!( + "sb: size {} nblocks {} ninodes {} nlog {} logstart {} inodestart {} bmap start {}", + sb.size, sb.nblocks, sb.ninodes, sb.nlog, sb.logstart, sb.inodestart, sb.bmapstart + ); + } +} + +fn bzero(dev: u32, bno: u32) { + let bp = bio::bread(dev, bno); + bio::buf_mut(bp).data.fill(0); + log::log_write(bp); + bio::brelse(bp); +} + +fn balloc(dev: u32) -> u32 { + unsafe { + let mut b = 0u32; + while b < SB.size { + let bp = bio::bread(dev, bblock(b, &*(&raw const SB))); + let mut found: Option = None; + { + let data = &mut bio::buf_mut(bp).data; + let mut bi = 0u32; + while bi < (BPB as u32) && b + bi < SB.size { + let m: u8 = 1u8 << (bi % 8); + let idx = (bi / 8) as usize; + if (data[idx] & m) == 0 { + data[idx] |= m; + found = Some(b + bi); + break; + } + bi += 1; + } + } + + if let Some(blockno) = found { + log::log_write(bp); + bio::brelse(bp); + bzero(dev, blockno); + return blockno; + } + + bio::brelse(bp); + b += BPB as u32; + } + } + + panic!("balloc: out of blocks"); +} + +fn bfree(dev: u32, b: u32) { + unsafe { + let bp = bio::bread(dev, bblock(b, &*(&raw const SB))); + let bi = b % (BPB as u32); + let m: u8 = 1u8 << (bi % 8); + let idx = (bi / 8) as usize; + + { + let data = &mut bio::buf_mut(bp).data; + if (data[idx] & m) == 0 { + panic!("freeing free block"); + } + data[idx] &= !m; + } + + log::log_write(bp); + bio::brelse(bp); + } +} + +pub fn ialloc(dev: u32, type_: i16) -> usize { + unsafe { + let mut inum = 1u32; + while inum < SB.ninodes { + let bp = bio::bread(dev, iblock(inum, &*(&raw const SB))); + let off = (inum % (IPB as u32)) as usize * DINODE_SIZE; + + let free = { + let data = &bio::buf_mut(bp).data; + read_i16_le(data, off) == 0 + }; + + if free { + { + let data = &mut bio::buf_mut(bp).data; + data[off..off + DINODE_SIZE].fill(0); + write_i16_le(data, off, type_); + } + log::log_write(bp); + bio::brelse(bp); + return iget(dev, inum); + } + + bio::brelse(bp); + inum += 1; + } + } + + panic!("ialloc: no inodes"); +} + +fn itrunc(idx: usize) { + unsafe { + if idx >= NINODE { + panic!("itrunc: bad inode index"); + } + + let dev = ICACHE.inode[idx].dev; + for i in 0..NDIRECT { + let addr = ICACHE.inode[idx].addrs[i]; + if addr != 0 { + bfree(dev, addr); + ICACHE.inode[idx].addrs[i] = 0; + } + } + + let indirect = ICACHE.inode[idx].addrs[NDIRECT]; + if indirect != 0 { + let bp = bio::bread(dev, indirect); + for j in 0..NINDIRECT { + let off = j * 4; + let a = { + let data = &bio::buf_mut(bp).data; + read_u32_le(data, off) + }; + if a != 0 { + bfree(dev, a); + } + } + bio::brelse(bp); + bfree(dev, indirect); + ICACHE.inode[idx].addrs[NDIRECT] = 0; + } + + ICACHE.inode[idx].size = 0; + } + + iupdate(idx); +} + +pub fn iput(idx: usize) { + unsafe { + if idx >= NINODE { + panic!("iput: bad inode index"); + } + if ICACHE.inode[idx].refcnt < 1 { + panic!("iput: ref underflow"); + } + + if ICACHE.inode[idx].valid != 0 && ICACHE.inode[idx].nlink == 0 && ICACHE.inode[idx].refcnt == 1 { + itrunc(idx); + ICACHE.inode[idx].type_ = 0; + iupdate(idx); + ICACHE.inode[idx].valid = 0; + } + + ICACHE.inode[idx].refcnt -= 1; + } +} + +pub fn irelease(idx: usize) { + iput(idx); +} + +pub fn iupdate(idx: usize) { + unsafe { + if idx >= NINODE { + panic!("iupdate: bad inode index"); + } + + let ip = &ICACHE.inode[idx]; + let bp = bio::bread(ip.dev, iblock(ip.inum, &*(&raw const SB))); + let off = (ip.inum % (IPB as u32)) as usize * DINODE_SIZE; + + { + let data = &mut bio::buf_mut(bp).data; + write_i16_le(data, off, ip.type_); + write_i16_le(data, off + 2, ip.major); + write_i16_le(data, off + 4, ip.minor); + write_i16_le(data, off + 6, ip.nlink); + write_u32_le(data, off + 8, ip.size); + for i in 0..(NDIRECT + 1) { + write_u32_le(data, off + 12 + (i * 4), ip.addrs[i]); + } + } + + log::log_write(bp); + bio::brelse(bp); + } +} + +pub fn iget(dev: u32, inum: u32) -> usize { + unsafe { + let mut empty: Option = None; + + for i in 0..NINODE { + let ip = &mut ICACHE.inode[i]; + + if ip.refcnt > 0 && ip.dev == dev && ip.inum == inum { + ip.refcnt += 1; + return i; + } + + if empty.is_none() && ip.refcnt == 0 { + empty = Some(i); + } + } + + let idx = empty.unwrap_or_else(|| panic!("iget: no inodes")); + let ip = &mut ICACHE.inode[idx]; + + ip.dev = dev; + ip.inum = inum; + ip.refcnt = 1; + ip.valid = 0; + + idx + } +} + +pub fn iread(idx: usize) { + unsafe { + if idx >= NINODE { + panic!("iread: bad inode index"); + } + + let ip = &mut ICACHE.inode[idx]; + if ip.refcnt < 1 { + panic!("iread"); + } + + if ip.valid == 0 { + let bp = bio::bread(ip.dev, iblock(ip.inum, &*(&raw const SB))); + let data = &bio::buf_mut(bp).data; + + let off = (ip.inum % (IPB as u32)) as usize * DINODE_SIZE; + ip.type_ = read_i16_le(data, off); + ip.major = read_i16_le(data, off + 2); + ip.minor = read_i16_le(data, off + 4); + ip.nlink = read_i16_le(data, off + 6); + ip.size = read_u32_le(data, off + 8); + + for i in 0..(NDIRECT + 1) { + ip.addrs[i] = read_u32_le(data, off + 12 + (i * 4)); + } + + bio::brelse(bp); + + ip.valid = 1; + if ip.type_ == 0 { + panic!("iread: no type"); + } + } + } +} + +fn bmap(idx: usize, bn: u32) -> u32 { + unsafe { + if idx >= NINODE { + panic!("bmap: bad inode index"); + } + + let ip = &mut ICACHE.inode[idx]; + + if (bn as usize) < NDIRECT { + let direct = &mut ip.addrs[bn as usize]; + if *direct == 0 { + *direct = balloc(ip.dev); + } + return *direct; + } + + let bn = bn - (NDIRECT as u32); + if (bn as usize) < NINDIRECT { + if ip.addrs[NDIRECT] == 0 { + ip.addrs[NDIRECT] = balloc(ip.dev); + } + + let bp = bio::bread(ip.dev, ip.addrs[NDIRECT]); + let mut addr = { + let data = &bio::buf_mut(bp).data; + read_u32_le(data, (bn as usize) * 4) + }; + if addr == 0 { + addr = balloc(ip.dev); + { + let data = &mut bio::buf_mut(bp).data; + write_u32_le(data, (bn as usize) * 4, addr); + } + log::log_write(bp); + } + bio::brelse(bp); + return addr; + } + } + + panic!("bmap: out of range"); +} + +pub fn stati(idx: usize, st: &mut Stat) { + unsafe { + if idx >= NINODE { + panic!("stati: bad inode index"); + } + + let ip = &ICACHE.inode[idx]; + st.dev = ip.dev as i32; + st.ino = ip.inum; + st.type_ = ip.type_; + st.nlink = ip.nlink; + st.size = ip.size; + } +} + +pub fn readi(idx: usize, dst: &mut [u8], off: u32, n: u32) -> i32 { + unsafe { + if idx >= NINODE { + panic!("readi: bad inode index"); + } + + let ip = &ICACHE.inode[idx]; + + // Handle device files + if ip.type_ == T_DEV as i16 { + if ip.major < 0 || (ip.major as usize) >= NDEV || DEVSW[ip.major as usize].read.is_none() { + return -1; + } + return DEVSW[ip.major as usize].read.unwrap()(idx, dst, n as i32); + } + + if off > ip.size || off.checked_add(n).is_none() || ip.nlink < 1 { + return -1; + } + + let mut n = n; + if off + n > ip.size { + n = ip.size - off; + } + + if (n as usize) > dst.len() { + panic!("readi: destination too small"); + } + + let mut tot: u32 = 0; + let mut cur_off = off; + let dev = ip.dev; + + while tot < n { + let bp = bio::bread(dev, bmap(idx, cur_off / (BSIZE as u32))); + + let m = min((n - tot) as usize, BSIZE - (cur_off as usize % BSIZE)); + let boff = cur_off as usize % BSIZE; + dst[tot as usize..tot as usize + m] + .copy_from_slice(&bio::buf_mut(bp).data[boff..boff + m]); + bio::brelse(bp); + + tot += m as u32; + cur_off += m as u32; + } + + n as i32 + } +} + +pub fn writei(idx: usize, src: &[u8], off: u32, n: u32) -> i32 { + unsafe { + if idx >= NINODE { + panic!("writei: bad inode index"); + } + + let ip = &ICACHE.inode[idx]; + + // Handle device files + if ip.type_ == T_DEV as i16 { + if ip.major < 0 || (ip.major as usize) >= NDEV || DEVSW[ip.major as usize].write.is_none() { + return -1; + } + return DEVSW[ip.major as usize].write.unwrap()(idx, src, n as i32); + } + + if off > ip.size || off.checked_add(n).is_none() { + return -1; + } + if off + n > (MAXFILE * BSIZE) as u32 { + return -1; + } + if (n as usize) > src.len() { + panic!("writei: source too small"); + } + + let dev = ip.dev; + let mut tot: u32 = 0; + let mut cur_off = off; + + while tot < n { + let bp = bio::bread(dev, bmap(idx, cur_off / (BSIZE as u32))); + let m = min((n - tot) as usize, BSIZE - (cur_off as usize % BSIZE)); + let boff = cur_off as usize % BSIZE; + bio::buf_mut(bp).data[boff..boff + m] + .copy_from_slice(&src[tot as usize..tot as usize + m]); + log::log_write(bp); + bio::brelse(bp); + + tot += m as u32; + cur_off += m as u32; + } + + if n > 0 && cur_off > ICACHE.inode[idx].size { + ICACHE.inode[idx].size = cur_off; + iupdate(idx); + } + + n as i32 + } +} + +pub fn inode_inum(idx: usize) -> u32 { + unsafe { + if idx >= NINODE { + panic!("inode_inum: bad inode index"); + } + ICACHE.inode[idx].inum + } +} + +pub fn inode_dev(idx: usize) -> u32 { + unsafe { + if idx >= NINODE { + panic!("inode_dev: bad inode index"); + } + ICACHE.inode[idx].dev + } +} + +pub fn inode_type(idx: usize) -> u16 { + unsafe { + if idx >= NINODE { + panic!("inode_type: bad inode index"); + } + ICACHE.inode[idx].type_ as u16 + } +} + +pub fn inode_nlink(idx: usize) -> u16 { + unsafe { + if idx >= NINODE { + panic!("inode_nlink: bad inode index"); + } + ICACHE.inode[idx].nlink as u16 + } +} + +pub fn inode_size(idx: usize) -> u32 { + unsafe { + if idx >= NINODE { + panic!("inode_size: bad inode index"); + } + ICACHE.inode[idx].size + } +} + +pub fn inode_set_meta(idx: usize, major: i16, minor: i16, nlink: i16) { + unsafe { + if idx >= NINODE { + panic!("inode_set_meta: bad inode index"); + } + ICACHE.inode[idx].major = major; + ICACHE.inode[idx].minor = minor; + ICACHE.inode[idx].nlink = nlink; + } +} + +pub fn inode_inc_nlink(idx: usize) { + unsafe { + if idx >= NINODE { + panic!("inode_inc_nlink: bad inode index"); + } + ICACHE.inode[idx].nlink += 1; + } +} + +pub fn inode_dec_nlink(idx: usize) { + unsafe { + if idx >= NINODE { + panic!("inode_dec_nlink: bad inode index"); + } + ICACHE.inode[idx].nlink -= 1; + } +} + +pub fn namecmp(s: &str, t: &[u8; DIRSIZ]) -> bool { + name_to_dirsiz(s) == *t +} + +pub fn dirlookup(dp_idx: usize, name: &str, mut poff: Option<&mut u32>) -> Option { + if dp_idx >= NINODE { + panic!("dirlookup: bad inode index"); + } + iread(dp_idx); + + unsafe { + let dp = &ICACHE.inode[dp_idx]; + if (dp.type_ as u16) != T_DIR { + panic!("dirlookup not DIR"); + } + + let mut off = 0u32; + while off < dp.size { + let mut raw = [0u8; DIRENT_SIZE]; + if readi(dp_idx, &mut raw, off, DIRENT_SIZE as u32) != DIRENT_SIZE as i32 { + panic!("dirlookup read"); + } + let de = parse_dirent(&raw); + if de.inum != 0 && namecmp(name, &de.name) { + if let Some(ref mut out_off) = poff { + **out_off = off; + } + return Some(iget(dp.dev, de.inum as u32)); + } + off += DIRENT_SIZE as u32; + } + } + + None +} + +pub fn dirlink(dp_idx: usize, name: &str, inum: u32) -> i32 { + if let Some(ip_idx) = dirlookup(dp_idx, name, None) { + iput(ip_idx); + return -1; + } + + let mut off = 0u32; + unsafe { + if dp_idx >= NINODE { + panic!("dirlink: bad inode index"); + } + while off < ICACHE.inode[dp_idx].size { + let mut raw = [0u8; DIRENT_SIZE]; + if readi(dp_idx, &mut raw, off, DIRENT_SIZE as u32) != DIRENT_SIZE as i32 { + panic!("dirlink read"); + } + let de = parse_dirent(&raw); + if de.inum == 0 { + break; + } + off += DIRENT_SIZE as u32; + } + } + + let mut raw = [0u8; DIRENT_SIZE]; + write_u16_le(&mut raw, 0, inum as u16); + raw[2..2 + DIRSIZ].copy_from_slice(&name_to_dirsiz(name)); + if writei(dp_idx, &raw, off, DIRENT_SIZE as u32) != DIRENT_SIZE as i32 { + panic!("dirlink"); + } + + 0 +} + +fn skipelem(path: &[u8], mut i: usize, name: &mut [u8; DIRSIZ]) -> Option { + while i < path.len() && path[i] == b'/' { + i += 1; + } + if i == path.len() { + return None; + } + + let start = i; + // Find end of this path element + while i < path.len() && path[i] != b'/' && path[i] != 0 { + i += 1; + } + let len = i - start; + + name.fill(0); + if len >= DIRSIZ { + name.copy_from_slice(&path[start..start + DIRSIZ]); + } else { + name[..len].copy_from_slice(&path[start..i]); + } + + while i < path.len() && path[i] == b'/' { + i += 1; + } + Some(i) +} + +fn namex(path: &str, nameiparent: bool, name: &mut [u8; DIRSIZ]) -> Option { + let bytes = path.as_bytes(); + let mut path_idx = 0usize; + let mut ip = iget(ROOTDEV, ROOTINO); + + while let Some(next_idx) = skipelem(bytes, path_idx, name) { + path_idx = next_idx; + iread(ip); + + unsafe { + if ICACHE.inode[ip].type_ as u16 != T_DIR { + iput(ip); + return None; + } + } + + if nameiparent && path_idx == bytes.len() { + return Some(ip); + } + + let elem = core::str::from_utf8(name).unwrap_or(""); + let trimmed = elem.trim_end_matches('\0'); + let next = match dirlookup(ip, trimmed, None) { + Some(x) => x, + None => { + iput(ip); + return None; + } + }; + iput(ip); + ip = next; + } + + if nameiparent { + iput(ip); + return None; + } + Some(ip) +} + +/// Look up the inode for a path name. +pub fn namei(path: &str) -> Option { + let mut name = [0u8; DIRSIZ]; + namex(path, false, &mut name) +} + +/// Look up the parent inode for a path name. +/// Copy the final path element into name. +pub fn nameiparent(path: &str, name: &mut [u8; DIRSIZ]) -> Option { + namex(path, true, name) +} diff --git a/src/ide.rs b/src/ide.rs new file mode 100644 index 0000000..99619f2 --- /dev/null +++ b/src/ide.rs @@ -0,0 +1,181 @@ +use core::sync::atomic::Ordering; +use crate::constants::BSIZE; +use crate::buf::{B_DIRTY, B_VALID}; +use crate::x86; + +const SECTOR_SIZE: usize = 512; + +const IDE_BSY: u8 = 0x80; +const IDE_DRDY: u8 = 0x40; +const IDE_DF: u8 = 0x20; +const IDE_ERR: u8 = 0x01; + +const IDE_CMD_READ: u8 = 0x20; +const IDE_CMD_WRITE: u8 = 0x30; +const IDE_CMD_RDMUL: u8 = 0xC4; +const IDE_CMD_WRMUL: u8 = 0xC5; + +// If you later build a real FS image, keep this consistent with your mkfs. +// xv6 uses 1000. +const FSSIZE: u32 = 1000; + +static mut IDEQUEUE: Option = None; +static mut HAVEDISK1: bool = false; + +fn idewait(checkerr: bool) -> i32 { + let mut r: u8; + loop { + r = x86::inb(0x1F7); + if (r & (IDE_BSY | IDE_DRDY)) == IDE_DRDY { + break; + } + } + if checkerr && (r & (IDE_DF | IDE_ERR)) != 0 { + return -1; + } + 0 +} + +pub fn ideinit() { + // Route IDE IRQ somewhere; simplest is CPU 0 for now. + crate::ioapic::ioapic_enable(crate::constants::IRQ_IDE, 0); + + idewait(false); + + // Check if disk 1 is present + unsafe { + x86::outb(0x1F6, 0xE0 | (1 << 4)); + for _ in 0..1000 { + if x86::inb(0x1F7) != 0 { + HAVEDISK1 = true; + break; + } + } + // Switch back to disk 0 + x86::outb(0x1F6, 0xE0 | (0 << 4)); + } +} + +fn idestart(idx: usize) { + let b = crate::bio::buf_mut(idx); + + if b.blockno >= FSSIZE { + panic!("idestart: incorrect blockno"); + } + + let sector_per_block = BSIZE / SECTOR_SIZE; // usually 1 + let sector = (b.blockno as usize) * sector_per_block; + + let read_cmd = if sector_per_block == 1 { IDE_CMD_READ } else { IDE_CMD_RDMUL }; + let write_cmd = if sector_per_block == 1 { IDE_CMD_WRITE } else { IDE_CMD_WRMUL }; + + if sector_per_block > 7 { + panic!("idestart: sector_per_block > 7"); + } + + idewait(false); + x86::outb(0x3F6, 0); // generate interrupt + + x86::outb(0x1F2, sector_per_block as u8); // number of sectors + x86::outb(0x1F3, (sector & 0xFF) as u8); + x86::outb(0x1F4, ((sector >> 8) & 0xFF) as u8); + x86::outb(0x1F5, ((sector >> 16) & 0xFF) as u8); + x86::outb( + 0x1F6, + 0xE0 | (((b.dev & 1) as u8) << 4) | (((sector >> 24) & 0x0F) as u8), + ); + + let flags = b.flags.load(Ordering::Acquire); + if (flags & B_DIRTY) != 0 { + x86::outb(0x1F7, write_cmd); + + // write BSIZE bytes as u32 words + unsafe { + x86::outsl(0x1F0, b.data.as_ptr() as *const u32, BSIZE / 4); + } + } else { + x86::outb(0x1F7, read_cmd); + } +} + +// Interrupt handler. +pub fn ideintr() { + let idx = unsafe { + match IDEQUEUE { + None => return, + Some(i) => { + let b = crate::bio::buf_mut(i); + IDEQUEUE = b.qnext; + b.qnext = None; + i + } + } + }; + + let b = crate::bio::buf_mut(idx); + + let flags = b.flags.load(Ordering::Acquire); + + // Read data if needed. + if (flags & B_DIRTY) == 0 && idewait(true) >= 0 { + unsafe { + x86::insl(0x1F0, b.data.as_mut_ptr() as *mut u32, BSIZE / 4); + } + } + + b.flags.fetch_or(B_VALID, Ordering::AcqRel); + b.flags.fetch_and(!B_DIRTY, Ordering::AcqRel); + + // Start next buffer in queue. + unsafe { + if let Some(next) = IDEQUEUE { + idestart(next); + } + } +} + +// Sync buf with disk. +// If B_DIRTY is set, write buf to disk, clear B_DIRTY, set B_VALID. +// Else if B_VALID is not set, read buf from disk, set B_VALID. +pub fn iderw(idx: usize) { + let b = crate::bio::buf_mut(idx); + + let flags = b.flags.load(Ordering::Acquire); + if (flags & (B_VALID | B_DIRTY)) == B_VALID { + panic!("iderw: nothing to do"); + } + + unsafe { + if b.dev != 0 && !HAVEDISK1 { + panic!("iderw: ide disk 1 not present"); + } + } + + // Append b to idequeue. + b.qnext = None; + unsafe { + let mut pp: *mut Option = &raw mut IDEQUEUE; + while let Some(next_idx) = *pp { + pp = &raw mut crate::bio::buf_mut(next_idx).qnext; + } + *pp = Some(idx); + } + + // Start disk if necessary. + unsafe { + if IDEQUEUE == Some(idx) { + idestart(idx); + } + } + + // Wait for request to finish. + // The interrupt handler will set B_VALID when done. + loop { + let flags = b.flags.load(Ordering::Acquire); + if (flags & (B_VALID | B_DIRTY)) == B_VALID { + break; + } + // Force compiler to re-read b->flags which is modified by ideintr() + x86::noop(); + } +} \ No newline at end of file diff --git a/src/ioapic.rs b/src/ioapic.rs index 15cf837..eaf9d70 100644 --- a/src/ioapic.rs +++ b/src/ioapic.rs @@ -1,7 +1,7 @@ use core::ptr::{read_volatile, write_volatile}; use crate::mp::MP_ONCE; -use crate::console::Console; -use core::fmt::Write; +// use crate::console::Console; +// use core::fmt::Write; use crate::println; // I/O APIC default physical address @@ -14,9 +14,9 @@ const REG_TABLE: u32 = 0x10; // Redirection table base (0x10 / 4) // Redirection table configuration bits const INT_DISABLED: u32 = 0x00010000; // Interrupt disabled -const INT_LEVEL: u32 = 0x00008000; // Level-triggered -const INT_ACTIVELOW: u32 = 0x00002000; // Active low -const INT_LOGICAL: u32 = 0x00000800; // Destination is CPU ID +// const INT_LEVEL: u32 = 0x00008000; // Unused in p3 - Level-triggered +// const INT_ACTIVELOW: u32 = 0x00002000; // Unused in p3 - Active low +// const INT_LOGICAL: u32 = 0x00000800; // Unused in p3 - Destination is CPU ID pub const T_IRQ0: u32 = 32; diff --git a/src/kalloc.rs b/src/kalloc.rs new file mode 100644 index 0000000..6e65192 --- /dev/null +++ b/src/kalloc.rs @@ -0,0 +1,52 @@ +use crate::constants::{pgroundup, PGSIZE}; +use core::ptr::null_mut; + +#[repr(C)] +struct Run { + next: *mut Run, +} + +struct KMem { + freelist: *mut Run, +} + +static mut KMEM: KMem = KMem { freelist: null_mut() }; + +extern "C" { + static end: u8; +} + +pub fn kinit(vstart: *mut u8, vend: *mut u8) { + freerange(vstart, vend); +} + +fn freerange(vstart: *mut u8, vend: *mut u8) { + let mut p = pgroundup(vstart as usize) as *mut u8; + while (p as usize) + PGSIZE as usize <= vend as usize { + kfree(p); + p = unsafe { p.add(PGSIZE as usize) }; + } +} + +pub fn kfree(v: *mut u8) { + if (v as usize) % PGSIZE as usize != 0 || (v as usize) < (unsafe { &end as *const u8 as usize }) { + panic!("kfree"); + } + + unsafe { + core::ptr::write_bytes(v, 1, PGSIZE as usize); + let r = v as *mut Run; + (*r).next = KMEM.freelist; + KMEM.freelist = r; + } +} + +pub fn kalloc() -> *mut u8 { + unsafe { + let r = KMEM.freelist; + if !r.is_null() { + KMEM.freelist = (*r).next; + } + r as *mut u8 + } +} diff --git a/src/lapic.rs b/src/lapic.rs index 1ce725f..5612dbb 100644 --- a/src/lapic.rs +++ b/src/lapic.rs @@ -1,6 +1,6 @@ use core::ptr::{read_volatile, write_volatile}; use crate::mp::MP_ONCE; -use crate::traps::{T_IRQ0, IRQ_TIMER, IRQ_SPURIOUS, IRQ_ERROR}; +use crate::constants::{IRQ_ERROR, IRQ_SPURIOUS, T_IRQ0}; const ID: isize = 0x0020 / 4; const VER: isize = 0x0030 / 4; @@ -14,14 +14,14 @@ const ESR: isize = 0x0280 / 4; const ICRLO: isize = 0x0300 / 4; const INIT: u32 = 0x00000500; -const STARTUP: u32 = 0x00000600; +// const STARTUP: u32 = 0x00000600; // Unused in p3 - for AP startup const DELIVS: u32 = 0x00001000; -const ASSERT: u32 = 0x00004000; -const DEASSERT: u32 = 0x00000000; +// const ASSERT: u32 = 0x00004000; // Unused in p3 - for IPI +// const DEASSERT: u32 = 0x00000000; // Unused in p3 - for IPI const LEVEL: u32 = 0x00008000; const BCAST: u32 = 0x00080000; -const BUSY: u32 = 0x00001000; -const FIXED: u32 = 0x00000000; +// const BUSY: u32 = 0x00001000; // Unused in p3 +// const FIXED: u32 = 0x00000000; // Unused in p3 const ICRHI: isize = 0x0310 / 4; const TIMER: isize = 0x0320 / 4; @@ -35,7 +35,7 @@ const ERROR: isize = 0x0370 / 4; const MASKED: u32 = 0x00010000; const TICR: isize = 0x0380 / 4; -const TCCR: isize = 0x0390 / 4; +// const TCCR: isize = 0x0390 / 4; // Unused in p3 - timer current count const TDCR: isize = 0x03E0 / 4; // Volatile write to LAPIC @@ -68,9 +68,10 @@ pub fn lapicinit() { // from lapic[TICR] and then issues an interrupt. // If xv6 cared more about precise timekeeping, // TICR would be calibrated using an external time source. - lapicw(TDCR, X1); - lapicw(TIMER, PERIODIC | (T_IRQ0 + IRQ_TIMER)); - lapicw(TICR, 1000000000); + // Timer disabled for p15 - will be re-enabled later + // lapicw(TDCR, X1); + // lapicw(TIMER, PERIODIC | (T_IRQ0 + IRQ_TIMER)); + // lapicw(TICR, 10000000); // Disable logical interrupt lines. diff --git a/src/lib.rs b/src/lib.rs index aa34772..345dd53 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -1,7 +1,10 @@ #![no_std] // No standard library #![no_main] // No main function +#![allow(dead_code)] use core::panic::PanicInfo; +use crate::x86::cli; +use crate::lapic::lapicid; mod param; mod x86; @@ -13,9 +16,20 @@ mod picirq; mod mp; mod proc; mod traps; -mod constants; - +mod constants; +mod buf; +mod bio; +mod ide; +mod fs; +mod fcntl; +mod file; +mod log; +mod mmu; +mod vm; +mod spinlock; +mod kalloc; use crate::traps::*; +use crate::constants::PHYSTOP; #[macro_export] macro_rules! println { @@ -30,32 +44,104 @@ macro_rules! println { fn halt() -> ! { println!("Bye COL{}\n\0", 331); loop { - x86::outw(0x604, 0x2000); - x86::outw(0xB004, 0x2000); + x86::outw(0x604, 0x2000); // QEMU isa-debug-exit device + x86::outw(0xB004, 0x2000); // VirtualBox shutdown port + } +} + +fn print_cstr(bytes: &[u8]) { + for &ch in bytes { + if ch == 0 { + break; + } + console::consputc(ch as i32); } } +fn welcome() { + // Use println! to verify we reach this point (goes via Console::Write, not file) + + let c = match file::open("/console", fcntl::O_RDWR) { + Some(fd) => { + fd + } + None => { + panic!("Failed to open console"); + } + }; + + let enter_message = b"\nEnter your name: "; + file::filewrite(c, enter_message, enter_message.len() as i32); + + let mut name = [0u8; 20]; + let nice_message = b"Nice to meet you! "; + let bye_message = b"BYE!\n"; + let namelen = file::fileread(c, &mut name, 20); + file::filewrite(c, nice_message, nice_message.len() as i32); + file::filewrite(c, &name[..namelen as usize], namelen); + file::filewrite(c, bye_message, bye_message.len() as i32); // Goodbye message is 5 bytes not 6 (Rust vs C string handling) + + file::fileclose(c); +} + extern "C" { - pub static alltraps: fn(); + pub fn alltraps(); } #[no_mangle] pub extern "C" fn entryofrust() -> ! { + extern "C" { + static end: u8; + } + + kalloc::kinit(unsafe { &end as *const u8 as *mut u8 }, PHYSTOP as *mut u8); mp::mpinit(); lapic::lapicinit(); picirq::picinit(); ioapic::ioapic_init(); + console::consoleinit(); uart::uartinit(); + ide::ideinit(); tvinit(); + bio::binit(); idtinit(); x86::sti(); - loop { - x86::wfi(); - } + fs::iinit(param::ROOTDEV); + log::initlog(param::ROOTDEV); + file::mknod("/console", param::CONSOLE as i16, param::CONSOLE as i16); + vm::seginit(); // segment descriptors + proc::pinit(); // first process + proc::pinit(); // another process + proc::scheduler(); // start running processes (never returns) } +static mut PANICKED: bool = false; + #[panic_handler] fn panic(info: &PanicInfo) -> ! { - println!("Kernel Panic: {:?}", info); - loop {} -} \ No newline at end of file + use core::fmt::Write; + + // Disable interrupts to prevent interrupt handlers from interfering + cli(); + + // Print panic message with LAPIC ID to identify which CPU panicked + let mut console = console::Console {}; + let _ = write!(&mut console, "lapicid {}: panic: ", lapicid()); + let _ = writeln!(&mut console, "{}", info); + + // Print stack trace + let mut pcs = [0u32; 10]; + let stack_ptr = &info as *const _ as *const u32; + spinlock::getcallerpcs(stack_ptr, &mut pcs); + + for &pc in &pcs { + if pc != 0 { + let _ = writeln!(&mut console, " {:#x}", pc); + } + } + + unsafe { PANICKED = true; } + + // Halt the system + halt(); +} diff --git a/src/log.rs b/src/log.rs new file mode 100644 index 0000000..36bd892 --- /dev/null +++ b/src/log.rs @@ -0,0 +1,189 @@ +use core::mem::size_of; +use core::sync::atomic::Ordering; + +use crate::bio; +use crate::buf::{B_DIRTY, BSIZE}; +use crate::fs; +use crate::param::LOGSIZE; + +#[derive(Copy, Clone)] +struct LogHeader { + n: i32, + block: [u32; LOGSIZE], +} + +impl LogHeader { + const fn new() -> Self { + Self { + n: 0, + block: [0; LOGSIZE], + } + } +} + +struct Log { + start: u32, + size: u32, + committing: bool, + dev: u32, + lh: LogHeader, +} + +impl Log { + const fn new() -> Self { + Self { + start: 0, + size: 0, + committing: false, + dev: 0, + lh: LogHeader::new(), + } + } +} + +static mut LOG: Log = Log::new(); + +#[inline] +fn read_i32_le(data: &[u8], off: usize) -> i32 { + i32::from_le_bytes([data[off], data[off + 1], data[off + 2], data[off + 3]]) +} + +#[inline] +fn write_i32_le(data: &mut [u8], off: usize, val: i32) { + data[off..off + 4].copy_from_slice(&val.to_le_bytes()); +} + +#[inline] +fn read_u32_le(data: &[u8], off: usize) -> u32 { + u32::from_le_bytes([data[off], data[off + 1], data[off + 2], data[off + 3]]) +} + +#[inline] +fn write_u32_le(data: &mut [u8], off: usize, val: u32) { + data[off..off + 4].copy_from_slice(&val.to_le_bytes()); +} + +fn read_head() { + unsafe { + let buf = bio::bread(LOG.dev, LOG.start); + let data = &bio::buf_mut(buf).data; + LOG.lh.n = read_i32_le(data, 0); + for i in 0..(LOG.lh.n as usize) { + LOG.lh.block[i] = read_u32_le(data, 4 + i * 4); + } + bio::brelse(buf); + } +} + +fn write_head() { + unsafe { + let buf = bio::bread(LOG.dev, LOG.start); + let data = &mut bio::buf_mut(buf).data; + data.fill(0); + write_i32_le(data, 0, LOG.lh.n); + for i in 0..(LOG.lh.n as usize) { + write_u32_le(data, 4 + i * 4, LOG.lh.block[i]); + } + bio::bwrite(buf); + bio::brelse(buf); + } +} + +fn install_trans() { + unsafe { + for tail in 0..(LOG.lh.n as usize) { + let lbuf = bio::bread(LOG.dev, LOG.start + tail as u32 + 1); + let dbuf = bio::bread(LOG.dev, LOG.lh.block[tail]); + let src = bio::buf_mut(lbuf).data; + bio::buf_mut(dbuf).data.copy_from_slice(&src); + bio::bwrite(dbuf); + bio::brelse(lbuf); + bio::brelse(dbuf); + } + } +} + +fn recover_from_log() { + read_head(); + install_trans(); + unsafe { + LOG.lh.n = 0; + } + write_head(); +} + +fn write_log() { + unsafe { + for tail in 0..(LOG.lh.n as usize) { + let to = bio::bread(LOG.dev, LOG.start + tail as u32 + 1); + let from = bio::bread(LOG.dev, LOG.lh.block[tail]); + let src = bio::buf_mut(from).data; + bio::buf_mut(to).data.copy_from_slice(&src); + bio::bwrite(to); + bio::brelse(from); + bio::brelse(to); + } + } +} + +fn commit() { + unsafe { + if LOG.committing { + panic!("commit"); + } + LOG.committing = true; + if LOG.lh.n > 0 { + write_log(); + write_head(); + install_trans(); + LOG.lh.n = 0; + write_head(); + } + LOG.committing = false; + } +} + +pub fn initlog(dev: u32) { + if size_of::() >= BSIZE { + panic!("initlog: too big logheader"); + } + + let mut sb = fs::Superblock::new(); + fs::readsb(dev, &mut sb); + unsafe { + LOG.start = sb.logstart; + LOG.size = sb.nlog; + LOG.dev = dev; + } + recover_from_log(); +} + +pub fn begin_op() {} + +pub fn end_op() { + commit(); +} + +pub fn log_write(idx: usize) { + unsafe { + let blockno = bio::buf_mut(idx).blockno; + if LOG.lh.n as usize >= LOGSIZE || LOG.lh.n as u32 >= LOG.size.saturating_sub(1) { + panic!("too big a transaction"); + } + + let mut i = 0usize; + while i < LOG.lh.n as usize { + if LOG.lh.block[i] == blockno { + break; + } + i += 1; + } + + LOG.lh.block[i] = blockno; + if i == LOG.lh.n as usize { + LOG.lh.n += 1; + } + + bio::buf_mut(idx).flags.fetch_or(B_DIRTY, Ordering::AcqRel); + } +} diff --git a/src/mkfs.rs b/src/mkfs.rs new file mode 100644 index 0000000..6289e66 --- /dev/null +++ b/src/mkfs.rs @@ -0,0 +1,388 @@ +use std::env; +use std::fs::{File, OpenOptions}; +use std::io::{Read, Seek, SeekFrom, Write}; +use std::mem::size_of; +use std::path::Path; + + +// ============================================================================ +// FILE SYSTEM CONSTANTS AND STRUCTURES +// ============================================================================ +// NOTE: These definitions are duplicated from the kernel codebase. +// +// WHY STANDALONE? +// In the C version, mkfs.c is compiled standalone with `gcc -o mkfs mkfs.c` +// and shares definitions via header files (fs.h, param.h, stat.h). +// +// Rust cannot use header files, so we duplicate the definitions here. +// This matches C's semantic model: mkfs is a host-side utility that runs +// on Linux/Mac (with std) to create fs.img BEFORE the kernel boots. +// +// The kernel (src/*) runs bare-metal x86 (no_std) and cannot share compiled +// code with host programs. +// +// MAINTENANCE: Keep synchronized with: +// - src/constants.rs (constants) +// - src/fs.rs (structs) - once created +// ============================================================================ + +// From fs.h (On-disk file system format) +const ROOTINO: u32 = 1; // root i-number +const BSIZE: usize = 512; // block size +const NDIRECT: usize = 12; // number of direct block pointers +const NINDIRECT: usize = BSIZE / size_of::(); // indirect pointers +const MAXFILE: usize = NDIRECT + NINDIRECT; // max file size in blocks +const DIRSIZ: usize = 14; // directory name length + +// From param.h (System parameters) +const FSSIZE: u32 = 1_000; // size of file system in blocks +const NINODES: u32 = 200; // number of inodes +const LOGSIZE: u32 = 30; // max data blocks in on-disk log + +// From stat.h (File types) +const T_DIR: u16 = 1; // Directory +const T_FILE: u16 = 2; // File + +// ============================================================================ +// FILESYSTEM STRUCTURES (Duplicated from src/fs.rs) +// ============================================================================ +// In C: These are defined in fs.h and included by both kernel and mkfs.c +// In Rust: Canonical definitions are in src/fs.rs (for kernel) +// Duplicated here because mkfs is a standalone host binary +// ============================================================================ + +#[repr(C)] +#[derive(Clone, Copy, Default)] +struct Superblock { + size: u32, + nblocks: u32, + ninodes: u32, + nlog: u32, + logstart: u32, + inodestart: u32, + bmapstart: u32, +} + +#[repr(C)] +#[derive(Clone, Copy)] +struct Dinode { + typ: u16, + major: u16, + minor: u16, + nlink: u16, + size: u32, + addrs: [u32; NDIRECT + 1], +} + +impl Default for Dinode { + fn default() -> Self { + Self { + typ: 0, + major: 0, + minor: 0, + nlink: 0, + size: 0, + addrs: [0; NDIRECT + 1], + } + } +} + +#[repr(C)] +#[derive(Clone, Copy)] +struct Dirent { + inum: u16, + name: [u8; DIRSIZ], +} + +impl Default for Dirent { + fn default() -> Self { + Self { + inum: 0, + name: [0; DIRSIZ], + } + } +} + +struct Mkfs { + fsfd: File, + sb: Superblock, + freeinode: u32, + freeblock: u32, +} + +fn as_bytes(val: &T) -> &[u8] { + unsafe { std::slice::from_raw_parts((val as *const T).cast::(), size_of::()) } +} + +fn from_bytes(bytes: &[u8]) -> T { + assert_eq!(bytes.len(), size_of::()); + let mut out = std::mem::MaybeUninit::::uninit(); + unsafe { + std::ptr::copy_nonoverlapping(bytes.as_ptr(), out.as_mut_ptr().cast::(), bytes.len()); + out.assume_init() + } +} + +fn name_to_dirent(name: &str, inum: u16) -> Dirent { + let mut de = Dirent { + inum: inum.to_le(), + ..Default::default() + }; + let name_bytes = name.as_bytes(); + let copy_len = name_bytes.len().min(DIRSIZ); + de.name[..copy_len].copy_from_slice(&name_bytes[..copy_len]); + de +} + +impl Mkfs { + fn new(fsfd: File, sb: Superblock, freeblock: u32) -> Self { + Self { + fsfd, + sb, + freeinode: 1, + freeblock, + } + } + + fn wsect(&mut self, sec: u32, buf: &[u8; BSIZE]) { + let off = (sec as u64) * (BSIZE as u64); + self.fsfd + .seek(SeekFrom::Start(off)) + .expect("lseek(write) failed"); + self.fsfd.write_all(buf).expect("write failed"); + } + + fn rsect(&mut self, sec: u32, buf: &mut [u8; BSIZE]) { + let off = (sec as u64) * (BSIZE as u64); + self.fsfd + .seek(SeekFrom::Start(off)) + .expect("lseek(read) failed"); + self.fsfd.read_exact(buf).expect("read failed"); + } + + fn iblock(&self, inum: u32) -> u32 { + (inum / ipb() as u32) + u32::from_le(self.sb.inodestart) + } + + fn winode(&mut self, inum: u32, ip: &Dinode) { + let mut buf = [0u8; BSIZE]; + let bn = self.iblock(inum); + self.rsect(bn, &mut buf); + + let off = (inum as usize % ipb()) * size_of::(); + let src = as_bytes(ip); + buf[off..off + size_of::()].copy_from_slice(src); + self.wsect(bn, &buf); + } + + fn rinode(&mut self, inum: u32) -> Dinode { + let mut buf = [0u8; BSIZE]; + let bn = self.iblock(inum); + self.rsect(bn, &mut buf); + + let off = (inum as usize % ipb()) * size_of::(); + from_bytes::(&buf[off..off + size_of::()]) + } + + fn ialloc(&mut self, typ: u16) -> u32 { + let inum = self.freeinode; + self.freeinode += 1; + + let din = Dinode { + typ: typ.to_le(), + nlink: 1u16.to_le(), + size: 0u32.to_le(), + ..Default::default() + }; + self.winode(inum, &din); + inum + } + + fn balloc(&mut self, used: u32) { + assert!(used < (BSIZE * 8) as u32); + println!("balloc: first {} blocks have been allocated", used); + + let mut buf = [0u8; BSIZE]; + for i in 0..used { + let idx = (i / 8) as usize; + let bit = (i % 8) as u8; + buf[idx] |= 1u8 << bit; + } + + let bmapstart = u32::from_le(self.sb.bmapstart); + println!("balloc: write bitmap block at sector {}", bmapstart); + self.wsect(bmapstart, &buf); + } + + fn iappend(&mut self, inum: u32, mut p: &[u8]) { + let mut din = self.rinode(inum); + let mut off = u32::from_le(din.size); + + while !p.is_empty() { + let fbn = (off as usize) / BSIZE; + assert!(fbn < MAXFILE); + + let x: u32; + if fbn < NDIRECT { + if u32::from_le(din.addrs[fbn]) == 0 { + din.addrs[fbn] = self.freeblock.to_le(); + self.freeblock += 1; + } + x = u32::from_le(din.addrs[fbn]); + } else { + if u32::from_le(din.addrs[NDIRECT]) == 0 { + din.addrs[NDIRECT] = self.freeblock.to_le(); + self.freeblock += 1; + } + + let mut indirect_sector = [0u8; BSIZE]; + let indirect_blockno = u32::from_le(din.addrs[NDIRECT]); + self.rsect(indirect_blockno, &mut indirect_sector); + + let indirect_idx = fbn - NDIRECT; + let byte_off = indirect_idx * size_of::(); + let mut indirect_entry = u32::from_le(from_bytes::( + &indirect_sector[byte_off..byte_off + size_of::()], + )); + + if indirect_entry == 0 { + indirect_entry = self.freeblock; + self.freeblock += 1; + let le = indirect_entry.to_le(); + indirect_sector[byte_off..byte_off + size_of::()].copy_from_slice(as_bytes(&le)); + self.wsect(indirect_blockno, &indirect_sector); + } + + x = indirect_entry; + } + + let mut buf = [0u8; BSIZE]; + self.rsect(x, &mut buf); + + let n1 = p + .len() + .min((fbn as u32 + 1) as usize * BSIZE - off as usize); + let block_off = off as usize - (fbn * BSIZE); + buf[block_off..block_off + n1].copy_from_slice(&p[..n1]); + self.wsect(x, &buf); + + off += n1 as u32; + p = &p[n1..]; + } + + din.size = off.to_le(); + self.winode(inum, &din); + } +} + +fn ipb() -> usize { + BSIZE / size_of::() +} + +fn main() { + assert_eq!(size_of::(), 4, "Integers must be 4 bytes"); + assert_eq!(BSIZE % size_of::(), 0); + assert_eq!(BSIZE % size_of::(), 0); + + let mut args = env::args().collect::>(); + if args.len() < 2 { + eprintln!("Usage: mkfs fs.img files..."); + std::process::exit(1); + } + + let fs_img = args.remove(1); + + let nbitmap = FSSIZE / (BSIZE as u32 * 8) + 1; + let ninodeblocks = NINODES / ipb() as u32 + 1; + let nlog = LOGSIZE; + let nmeta = 2 + nlog + ninodeblocks + nbitmap; + let nblocks = FSSIZE - nmeta; + + let sb = Superblock { + size: FSSIZE.to_le(), + nblocks: nblocks.to_le(), + ninodes: NINODES.to_le(), + nlog: nlog.to_le(), + logstart: 2u32.to_le(), + inodestart: (2 + nlog).to_le(), + bmapstart: (2 + nlog + ninodeblocks).to_le(), + }; + + println!( + "nmeta {} (boot, super, log blocks {} inode blocks {}, bitmap blocks {}) blocks {} total {}", + nmeta, nlog, ninodeblocks, nbitmap, nblocks, FSSIZE + ); + + let fsfd = OpenOptions::new() + .read(true) + .write(true) + .create(true) + .truncate(true) + .open(&fs_img) + .unwrap_or_else(|e| { + eprintln!("{}: {}", fs_img, e); + std::process::exit(1); + }); + + let mut mkfs = Mkfs::new(fsfd, sb, nmeta); + + let zeroes = [0u8; BSIZE]; + for i in 0..FSSIZE { + mkfs.wsect(i, &zeroes); + } + + let mut sb_buf = [0u8; BSIZE]; + sb_buf[..size_of::()].copy_from_slice(as_bytes(&mkfs.sb)); + mkfs.wsect(1, &sb_buf); + + let rootino = mkfs.ialloc(T_DIR); + assert_eq!(rootino, ROOTINO); + + let dot = name_to_dirent(".", rootino as u16); + mkfs.iappend(rootino, as_bytes(&dot)); + + let dotdot = name_to_dirent("..", rootino as u16); + mkfs.iappend(rootino, as_bytes(&dotdot)); + + for path in &args[1..] { + if path.contains('/') { + eprintln!("{}: must be a basename (no /)", path); + std::process::exit(1); + } + + let mut host_file = File::open(path).unwrap_or_else(|e| { + eprintln!("{}: {}", path, e); + std::process::exit(1); + }); + + let file_name = if let Some(stripped) = path.strip_prefix('_') { + stripped + } else { + Path::new(path) + .file_name() + .and_then(|s| s.to_str()) + .unwrap_or(path) + }; + + let inum = mkfs.ialloc(T_FILE); + let de = name_to_dirent(file_name, inum as u16); + mkfs.iappend(rootino, as_bytes(&de)); + + let mut buf = [0u8; BSIZE]; + loop { + let cc = host_file.read(&mut buf).expect("read input file failed"); + if cc == 0 { + break; + } + mkfs.iappend(inum, &buf[..cc]); + } + } + + let mut din = mkfs.rinode(rootino); + let mut off = u32::from_le(din.size); + off = ((off / BSIZE as u32) + 1) * BSIZE as u32; + din.size = off.to_le(); + mkfs.winode(rootino, &din); + + mkfs.balloc(mkfs.freeblock); +} diff --git a/src/mmu.rs b/src/mmu.rs new file mode 100644 index 0000000..861dc0f --- /dev/null +++ b/src/mmu.rs @@ -0,0 +1,152 @@ +#![allow(unused_parens)] // False positive from bitfield macro + +use modular_bitfield::prelude::*; + +// Segment Descriptor + +#[bitfield] +#[repr(C, packed)] +#[derive(Clone, Copy, Default, Debug)] +pub struct SegDesc { + lim_15_0: B16, // Low bits of segment limit + base_15_0: B16, // Low bits of segment base address + base_23_16: B8, // Middle bits of segment base address + seg_type: B4, // Segment type (see STA_ constants) + s: B1, // 0 = system, 1 = application + dpl: B2, // Descriptor Privilege Level + p: B1, // Present + lim_19_16: B4, // High bits of segment limit + avl: B1, // Unused (available for software use) + rsv1: B1, // Reserved + db: B1, // 0 = 16-bit segment, 1 = 32-bit segment + g: B1, // Granularity: limit scaled by 4K when set + base_31_24: B8, // High bits of segment base address +} + +impl SegDesc { + /// Create a normal segment descriptor + /// Matches the C macro: SEG(type, base, lim, dpl) + pub fn seg(seg_type: u8, base: u32, lim: u32, dpl: u8) -> Self { + let mut seg = SegDesc::default(); + seg.set_lim_15_0(((lim >> 12) & 0xffff) as u16); + seg.set_base_15_0((base & 0xffff) as u16); + seg.set_base_23_16(((base >> 16) & 0xff) as u8); + seg.set_seg_type(seg_type); + seg.set_s(1); + seg.set_dpl(dpl); + seg.set_p(1); + seg.set_lim_19_16((lim >> 28) as u8); + seg.set_avl(0); + seg.set_rsv1(0); + seg.set_db(1); + seg.set_g(1); + seg.set_base_31_24(((base >> 24) & 0xff) as u8); + seg + } + + /// Create a 16-bit system segment descriptor. + /// Matches the C macro: SEG16(type, base, lim, dpl) + pub fn seg16(seg_type: u8, base: u32, lim: u32, dpl: u8) -> Self { + let mut seg = SegDesc::default(); + seg.set_lim_15_0((lim & 0xffff) as u16); + seg.set_base_15_0((base & 0xffff) as u16); + seg.set_base_23_16(((base >> 16) & 0xff) as u8); + seg.set_seg_type(seg_type); + seg.set_s(0); + seg.set_dpl(dpl); + seg.set_p(1); + seg.set_lim_19_16(((lim >> 16) & 0xf) as u8); + seg.set_avl(0); + seg.set_rsv1(0); + seg.set_db(0); + seg.set_g(0); + seg.set_base_31_24(((base >> 24) & 0xff) as u8); + seg + } +} + +#[repr(C)] +#[derive(Clone, Copy, Debug)] +pub struct TaskState { + pub link: u32, + pub esp0: u32, + pub ss0: u16, + pub padding1: u16, + pub esp1: u32, + pub ss1: u16, + pub padding2: u16, + pub esp2: u32, + pub ss2: u16, + pub padding3: u16, + pub cr3: u32, + pub eip: u32, + pub eflags: u32, + pub eax: u32, + pub ecx: u32, + pub edx: u32, + pub ebx: u32, + pub esp: u32, + pub ebp: u32, + pub esi: u32, + pub edi: u32, + pub es: u16, + pub padding4: u16, + pub cs: u16, + pub padding5: u16, + pub ss: u16, + pub padding6: u16, + pub ds: u16, + pub padding7: u16, + pub fs: u16, + pub padding8: u16, + pub gs: u16, + pub padding9: u16, + pub ldt: u16, + pub padding10: u16, + pub t: u16, + pub iomb: u16, +} + +impl TaskState { + pub const fn new() -> Self { + Self { + link: 0, + esp0: 0, + ss0: 0, + padding1: 0, + esp1: 0, + ss1: 0, + padding2: 0, + esp2: 0, + ss2: 0, + padding3: 0, + cr3: 0, + eip: 0, + eflags: 0, + eax: 0, + ecx: 0, + edx: 0, + ebx: 0, + esp: 0, + ebp: 0, + esi: 0, + edi: 0, + es: 0, + padding4: 0, + cs: 0, + padding5: 0, + ss: 0, + padding6: 0, + ds: 0, + padding7: 0, + fs: 0, + padding8: 0, + gs: 0, + padding9: 0, + ldt: 0, + padding10: 0, + t: 0, + iomb: 0, + } + } +} diff --git a/src/mp.rs b/src/mp.rs index 9684f51..1b5117e 100644 --- a/src/mp.rs +++ b/src/mp.rs @@ -4,7 +4,8 @@ use crate::x86::{outb, inb}; use crate::proc::Cpu; use core::cell::OnceCell; -pub static mut IOAPICID: u8 = 0; +// Removed: replaced by MP_ONCE.ioapic_id OnceCell pattern +// pub static mut IOAPICID: u8 = 0; #[derive(Debug, Clone, Copy)] #[repr(C)] @@ -59,7 +60,7 @@ pub struct MpIoApic { } // Processor flags -pub const MPBOOT: u8 = 0x02; // This proc is the bootstrap processor +// pub const MPBOOT: u8 = 0x02; // Unused in p3 - This proc is the bootstrap processor // Table entry types pub const MPPROC: u8 = 0x00; // One per processor @@ -194,7 +195,8 @@ pub fn mpinit() { let conf = unsafe { *(mp.physaddr as *mut MpConf) }; let mut ismp = true; - MP_ONCE.lapic_base.set(conf.lapicaddr as *mut u32); + MP_ONCE.lapic_base.set(conf.lapicaddr as *mut u32) + .expect("lapic_base already initialized"); let mut p = (mp.physaddr as usize + mem::size_of::()) as *const u8; let e = (mp.physaddr as usize + conf.length as usize) as *const u8; @@ -218,7 +220,8 @@ pub fn mpinit() { MPIOAPIC => { let ioapic = p as *const MpIoApic; let ioapicid = unsafe { (*ioapic).apicno }; - MP_ONCE.ioapic_id.set(ioapicid); + MP_ONCE.ioapic_id.set(ioapicid) + .expect("ioapic_id already initialized"); // p = unsafe{ p.add(mem::size_of::()) }; p = p.wrapping_add(mem::size_of::()); } @@ -236,7 +239,8 @@ pub fn mpinit() { if !ismp { panic!("Didn't find a suitable machine"); } - MP_ONCE.cpus.set(cpus); + MP_ONCE.cpus.set(cpus) + .expect("cpus array already initialized"); if mp.imcrp != 0 { // Bochs doesn't support IMCR, so this doesn't run on Bochs. diff --git a/src/param.rs b/src/param.rs index 4341329..2b4ebc4 100644 --- a/src/param.rs +++ b/src/param.rs @@ -1,2 +1,11 @@ -pub const KSTACKSIZE: usize = 4096; // size of per-process kernel stack +pub const NPROC: usize = 64; // maximum number of processes +pub const KSTACKSIZE: usize = 4096; // size of per-process kernel stack (unused in p3) pub const NCPU: usize = 8; // maximum number of CPUs +pub const MAXOPBLOCKS: usize = 10; // max # of blocks any FS op writes +pub const NOFILE: usize = 16; // open files per process +pub const NFILE: usize = 100; // open files per system +pub const NINODE: usize = 50; // maximum number of active i-nodes +pub const NDEV: usize = 10; // maximum major device number +pub const ROOTDEV: u32 = 1; // device number of file system root disk +pub const LOGSIZE: usize = MAXOPBLOCKS * 3; // max data blocks in on-disk log +pub const CONSOLE: usize = 1; // console device number diff --git a/src/proc.rs b/src/proc.rs index 279364c..0be5263 100644 --- a/src/proc.rs +++ b/src/proc.rs @@ -1,43 +1,270 @@ -use crate::mp::MP_ONCE; // Import the MP_ONCE static from mp.rs -use core::ptr; -use crate::x86::readeflags; -use crate::constants::{FL_IF,NCPU}; -use crate::lapic; +use crate::mp::MP_ONCE; +use crate::constants::{NSEGS, SEG_UCODE, SEG_UDATA, DPL_USER, FL_IF, PGSIZE}; +use crate::mmu::{SegDesc, TaskState}; +use crate::x86::TrapFrame; +use crate::param::KSTACKSIZE; +use crate::param::NPROC; +use crate::kalloc::kalloc; +use core::ptr::null_mut; +use core::cell::OnceCell; + +// Saved registers for kernel context switches. +// Don't need to save all the segment registers (%cs, etc), +// because they are constant across kernel contexts. +// Don't need to save %eax, %ecx, %edx, because the +// x86 convention is that the caller has saved them. +// Contexts are stored at the bottom of the stack they +// describe; the stack pointer is the address of the context. +// The layout of the context matches the layout of the stack in swtch.S +// at the "Switch stacks" comment. Switch doesn't save eip explicitly, +// but it is on the stack and allocproc() manipulates it. +#[repr(C)] +#[derive(Debug, Clone, Copy)] +pub struct Context { + pub edi: u32, + pub esi: u32, + pub ebx: u32, + pub ebp: u32, + pub eip: u32, +} + +#[derive(Debug, Clone, Copy, PartialEq, Eq)] +pub enum ProcState { + Unused, + Embryo, + Runnable, + Running, +} + +// Per-process state +#[repr(C)] +#[derive(Clone, Copy)] +pub struct Proc { + pub offset: *mut u8, // Process memory base + pub kstack: *mut u8, // Bottom of kernel stack for this process (unused for now) + pub state: ProcState, // Process state + pub pid: i32, // Process ID + pub parent: *mut Proc, // Parent process + pub tf: *mut TrapFrame, // Trap frame for current syscall + pub context: *mut Context, // swtch() here to run process + pub cwd: usize, // Current directory (inode number) + pub name: [u8; 16], // Process name (debugging) +} + +impl Proc { + pub const fn new() -> Self { + Self { + offset: null_mut(), + kstack: null_mut(), + state: ProcState::Unused, + pid: 0, + parent: null_mut(), + tf: null_mut(), + context: null_mut(), + cwd: 0, + name: [0; 16], + } + } +} + +// Process table +struct PTable { + proc: [Proc; NPROC], +} + +static mut PTABLE: PTable = PTable { + proc: [Proc::new(); NPROC], +}; +static mut NEXTPID: i32 = 1; #[derive(Debug, Clone, Copy)] pub struct Cpu { - pub apicid: u8, // Local APIC ID + pub apicid: u8, // Local APIC ID + pub scheduler: *mut Context, // swtch() here to enter scheduler + pub ts: TaskState, // Used by x86 to find stack for interrupt + pub gdt: [SegDesc; NSEGS], // x86 global descriptor table + pub ncli: i32, // Depth of pushcli nesting. + pub intena: bool, // Were interrupts enabled before pushcli? + pub proc: *mut Proc, // The process running on this cpu or null } impl Cpu { pub const fn new() -> Self { - Self { apicid: 0 } + Self { + apicid: 0, + scheduler: null_mut(), + ts: TaskState::new(), + gdt: [SegDesc::new(); NSEGS], + ncli: 0, + intena: false, + proc: null_mut(), + } } } pub fn cpuid() -> usize { + // For now, always return 0 (single CPU) + 0 +} + +pub fn mycpu() -> &'static mut Cpu { let cpus = MP_ONCE.cpus.get().expect("CPUs not initialized"); - unsafe { (mycpu() as *const Cpu).offset_from(cpus.as_ptr()) as usize } + unsafe { &mut *(cpus.as_ptr() as *mut Cpu).add(cpuid()) } } -pub fn mycpu() -> &'static Cpu { - let apicid: usize; - let mut i: usize = 0; +// Read proc from the cpu structure +pub fn myproc() -> Option<&'static mut Proc> { + let c = mycpu(); + if c.proc.is_null() { + None + } else { + Some(unsafe { &mut *c.proc }) + } +} + +// External symbols from assembly +extern "C" { + fn trapret(); + pub fn swtch(context: *mut Context); +} - if readeflags() & FL_IF != 0 { - panic!("mycpu called with interrupts enabled\n"); +// Look in the process table for an UNUSED proc. +// If found, change state to EMBRYO and initialize +// state required to run in the kernel. +// Otherwise return None. +fn allocproc() -> Option<&'static mut Proc> { + unsafe { + + + let ptable = &raw mut PTABLE; + + for p in &mut (*ptable).proc { + if p.state == ProcState::Unused { + // Found an unused process + p.state = ProcState::Embryo; + p.pid = NEXTPID; + NEXTPID += 1; + + p.offset = kalloc(); + if p.offset.is_null() { + p.state = ProcState::Unused; + return None; + } + + // Calculate stack pointer at the end of process memory + let sp = p.offset.add(PGSIZE as usize); + p.kstack = sp.sub(KSTACKSIZE); + + // Leave room for trap frame + let sp = sp.sub(core::mem::size_of::()); + p.tf = sp as *mut TrapFrame; + + // Leave room for context + let sp = sp.sub(core::mem::size_of::()); + p.context = sp as *mut Context; + + // Initialize context + core::ptr::write_bytes(p.context, 0, 1); + (*p.context).eip = trapret as *const () as usize as u32; + + return Some(p); + } + } + + None } +} - apicid = lapic::lapicid() as usize; +// Set up first process. +pub fn pinit() { + unsafe { + extern "C" { + static _binary_initcode_start: u8; + static _binary_initcode_size: u8; + } + + let p = allocproc().expect("Failed to allocate first process"); + + // Copy initcode binary to process memory + let dst = p.offset; + let src = &_binary_initcode_start as *const u8; + let size = &_binary_initcode_size as *const u8 as usize; + core::ptr::copy_nonoverlapping(src, dst, size); + + // Initialize trapframe + core::ptr::write_bytes(p.tf, 0, 1); + + (*p.tf).cs = ((SEG_UCODE << 3) | DPL_USER as u16) as u16; + (*p.tf).ds = ((SEG_UDATA << 3) | DPL_USER as u16) as u16; + (*p.tf).es = (*p.tf).ds; + (*p.tf).ss = (*p.tf).ds; + (*p.tf).eflags = FL_IF; + (*p.tf).esp = PGSIZE; + (*p.tf).eip = 0; // beginning of initcode.S + + // Set process name + let name = b"initcode"; + for (i, &byte) in name.iter().enumerate() { + p.name[i] = byte; + } + + // Set current working directory to root + p.cwd = crate::fs::namei("/").expect("Failed to find root directory"); + + p.state = ProcState::Runnable; + } +} - // Access the cpus array via MP_ONCE - let cpus = MP_ONCE.cpus.get().expect("CPUs not initialized"); +// Process scheduler. +// Scheduler never returns. It loops, doing: +// - choose a process to run +// - swtch to start running that process +pub fn scheduler() -> ! { + let c = mycpu(); + c.proc = null_mut(); + + loop { + // Enable interrupts on this processor. + crate::x86::sti(); + + // Loop over process table looking for process to run. + unsafe { + let ptable = &raw mut PTABLE; + + for p in &mut (*ptable).proc { + if p.state != ProcState::Runnable { + continue; + } + + // Switch to chosen process. + c.proc = p as *mut Proc; + p.state = ProcState::Running; + crate::vm::switchuvm(c.proc); + swtch(p.context); + + // Process is done running for now. + c.proc = null_mut(); + } + } + } +} - while i < NCPU { - if (cpus[i].apicid as usize) == apicid { - return &cpus[i]; +pub fn procdump() { + unsafe { + let ptable = &raw mut PTABLE; + for p in &(*ptable).proc { + if p.state == ProcState::Unused { + continue; + } + let state = match p.state { + ProcState::Unused => "unused", + ProcState::Embryo => "embryo", + ProcState::Runnable => "runble", + ProcState::Running => "run ", + }; + let name_len = p.name.iter().position(|&b| b == 0).unwrap_or(p.name.len()); + let name = core::str::from_utf8(&p.name[..name_len]).unwrap_or("???"); + crate::println!("{} {} {}", p.pid, state, name); } - i += 1; } - panic!("unknown apicid\n"); -} \ No newline at end of file +} diff --git a/src/spinlock.rs b/src/spinlock.rs new file mode 100644 index 0000000..ca47949 --- /dev/null +++ b/src/spinlock.rs @@ -0,0 +1,61 @@ +// Mutual exclusion spin locks and debugging utilities +use crate::constants::FL_IF; +use crate::proc::mycpu; +use crate::x86::{cli, readeflags, sti}; + +/// Record the current call stack in pcs[] by following the %ebp chain. +/// This function walks the stack frame pointers to collect return addresses. +pub fn getcallerpcs(v: *const u32, pcs: &mut [u32; 10]) { + unsafe { + let mut ebp = v.offset(-2) as *const u32; + let mut i = 0; + + while i < 10 { + // Check for invalid ebp values + // if(ebp == 0 || ebp < (uint*)KERNBASE || ebp == (uint*)0xffffffff) + if ebp.is_null() || ebp == 0xffffffff as *const u32 { + break; + } + + // pcs[i] = ebp[1]; // saved %eip + pcs[i] = *ebp.offset(1); + + // ebp = (uint*)ebp[0]; // saved %ebp + ebp = *ebp as *const u32; + + i += 1; + } + + // Fill rest with zeros + while i < 10 { + pcs[i] = 0; + i += 1; + } + } +} + +// Pushcli/popcli are like cli/sti except that they are matched: +// it takes two popcli to undo two pushcli. +pub fn pushcli() { + let eflags = readeflags(); + cli(); + let c = mycpu(); + if c.ncli == 0 { + c.intena = (eflags & FL_IF) != 0; + } + c.ncli += 1; +} + +pub fn popcli() { + if (readeflags() & FL_IF) != 0 { + panic!("popcli - interruptible"); + } + let c = mycpu(); + c.ncli -= 1; + if c.ncli < 0 { + panic!("popcli"); + } + if c.ncli == 0 && c.intena { + sti(); + } +} diff --git a/src/traps.rs b/src/traps.rs index 0643fcc..cd92d13 100644 --- a/src/traps.rs +++ b/src/traps.rs @@ -1,27 +1,22 @@ use modular_bitfield::prelude::*; -use core::cell::{OnceCell, RefCell}; +use core::cell::OnceCell; +use core::sync::atomic::{AtomicU32, Ordering}; +use core::ptr::addr_of_mut; use crate::proc::cpuid; use crate::println; use crate::lapic::lapiceoi; -use crate::x86::{lidt,rcr2}; +use crate::x86::{lidt, rcr2, TrapFrame}; use crate::lapic; - -const SEG_KCODE: u16 = 1; -const STS_IG32: u8 = 0xE; // 32-bit Interrupt Gate -const STS_TG32: u8 = 0xF; // 32-bit Trap Gate - -pub const T_IRQ0: u32 = 32; -pub const IRQ_TIMER: u32 = 0; -pub const IRQ_ERROR: u32 = 19; -pub const IRQ_SPURIOUS: u32 = 31; +use crate::constants::{IRQ_COM1, IRQ_SPURIOUS, IRQ_TIMER, T_IRQ0, SEG_KCODE, STS_IG32, STS_TG32}; +use crate::uart::uartintr; extern "C" { - static vectors: [usize; 256]; // remove assembly. + static vectors: [usize; 256]; // in vectors.S: array of 256 entry pointers } #[bitfield] #[repr(C, packed)] -#[derive(Clone, Copy, Default)] // debug can be removed ? do we need to ? +#[derive(Clone, Copy, Default)] pub struct GateDesc { off_15_0: B16, // low 16 bits of offset in segment cs: B16, // code segment selector @@ -40,7 +35,7 @@ impl GateDesc { self.set_args(0); self.set_rsv1(0); let typ = if is_trap { STS_TG32 } else { STS_IG32 }; - self.set_r_type(typ); // for an interrupt gate, for example. + self.set_r_type(typ); self.set_s(0); self.set_dpl(dpl); self.set_p(1); @@ -49,58 +44,27 @@ impl GateDesc { } -#[repr(C)] -pub struct IDTOnce { - pub idt: OnceCell<[GateDesc; 256]>, - pub ticks: RefCell -} -unsafe impl Sync for IDTOnce {} -pub static IDT: IDTOnce = IDTOnce { idt: OnceCell::new(), ticks: RefCell::new(0) }; - - -#[repr(C)] -pub struct TrapFrame { - // registers as pushed by pusha - pub edi: u32, - pub esi: u32, - pub ebp: u32, - pub oesp: u32, // useless & ignored - pub ebx: u32, - pub edx: u32, - pub ecx: u32, - pub eax: u32, - - pub trapno: u32, - - // below here defined by x86 hardware - pub err: u32, - pub eip: u32, - pub cs: u16, - pub padding5: u16, - pub eflags: u32, - - // below here only when crossing rings, such as from user to kernel - pub esp: u32, - pub ss: u16, - pub padding6: u16, -} - +static mut IDT: OnceCell<[GateDesc; 256]> = OnceCell::new(); +pub static TICKS: AtomicU32 = AtomicU32::new(0); pub fn tvinit() { let mut arr = [GateDesc::default(); 256]; for i in 0..256 { arr[i].set_gate( - false, // Use an interrupt gate. - SEG_KCODE << 3, // Code segment selector (shifted as in the C code). - unsafe { vectors[i] }, // Offset from the external vector table. - 0 // Descriptor privilege level. + false, + SEG_KCODE << 3, + unsafe { vectors[i] }, + 0 ); } - IDT.idt.set(arr); + unsafe { + let _ = (*addr_of_mut!(IDT)).set(arr); + } } pub fn idtinit() { - lidt(IDT.idt.get().unwrap() , core::mem::size_of::<[GateDesc; 256]>() as usize); + let idt = unsafe { (*addr_of_mut!(IDT)).get().expect("IDT not initialized") }; + lidt(idt, core::mem::size_of::<[GateDesc; 256]>() as usize); } @@ -116,22 +80,29 @@ pub extern "C" fn trap(orig_tf: *mut TrapFrame) { const TIMER: u32 = T_IRQ0 + IRQ_TIMER; const SPURIOUS: u32 = T_IRQ0 + IRQ_SPURIOUS; const SEVEN: u32 = T_IRQ0 + 7; - match tf.trapno { - TIMER => { - *IDT.ticks.borrow_mut() += 1; - println!("Tick {}!", IDT.ticks.borrow()); - lapic::lapiceoi(); - } - SEVEN | SPURIOUS => { - println!( - "cpu{}: spurious interrupt at {}:{}\n", - cpuid() , - tf.cs, - tf.eip - ); + TIMER => { + TICKS.fetch_add(1, Ordering::Relaxed); + lapic::lapiceoi(); + } + x if x == T_IRQ0 + IRQ_COM1 => { + uartintr(); + lapiceoi(); + } + SEVEN | SPURIOUS => { + println!( + "cpu{}: spurious interrupt at {:x}:{:x}\n", + cpuid(), + tf.cs, + tf.eip + ); lapiceoi(); } + crate::constants::IDE_TRAP => { + crate::ide::ideintr(); + crate::lapic::lapiceoi(); + } + _ => { println!( "unexpected trap {} from cpu {} eip {} (cr2=0x{:x})\n", @@ -143,4 +114,4 @@ pub extern "C" fn trap(orig_tf: *mut TrapFrame) { panic!("trap happened"); } } -} \ No newline at end of file +} diff --git a/src/uart.rs b/src/uart.rs index 9888088..025b678 100644 --- a/src/uart.rs +++ b/src/uart.rs @@ -1,7 +1,13 @@ -use crate::x86::{outb, inb}; +use crate::console::consoleintr; +use crate::x86::{inb, outb}; use crate::ioapic::ioapic_enable; +use core::sync::atomic::{AtomicBool, Ordering}; + const COM1: u16 = 0x3F8; // COM1 port address pub const IRQ_COM1: u32 = 4; + +static UART_READY: AtomicBool = AtomicBool::new(false); + pub fn uartinit() { // Turn off the FIFO. outb(COM1 + 2, 0); @@ -19,6 +25,7 @@ pub fn uartinit() { if inb(COM1 + 5) == 0xFF { return; } + UART_READY.store(true, Ordering::SeqCst); // Acknowledge pre-existing interrupt conditions; // enable interrupts. @@ -28,15 +35,33 @@ pub fn uartinit() { // Announce that the UART is active. for p in "xv6...\n".chars() { - uartputc(p); + uartputc(p as i32); } } -pub fn uartputc(c: char) { +pub fn uartputc(c: i32) { + if !UART_READY.load(Ordering::SeqCst) { + return; + } + for _ in 0..128 { if inb(COM1 + 5) & 0x20 != 0 { break; } } outb(COM1 + 0, c as u8); -} \ No newline at end of file +} + +fn uartgetc() -> i32 { + if !UART_READY.load(Ordering::SeqCst) { + return -1; + } + if (inb(COM1 + 5) & 0x01) == 0 { + return -1; + } + inb(COM1 + 0) as i32 +} + +pub fn uartintr() { + consoleintr(uartgetc); +} diff --git a/src/vm.rs b/src/vm.rs new file mode 100644 index 0000000..01d125e --- /dev/null +++ b/src/vm.rs @@ -0,0 +1,56 @@ +use crate::constants::{SEG_KCODE, SEG_KDATA, SEG_UCODE, SEG_UDATA, SEG_TSS, STA_X, STA_W, STA_R, PROCSIZE, DPL_USER, STS_T32A}; +use crate::mmu::SegDesc; +use crate::proc::{cpuid, mycpu, Proc}; +use crate::mp::MP_ONCE; +use crate::x86::{lgdt, ltr}; +use core::mem::{size_of, size_of_val}; +use crate::param::KSTACKSIZE; +use crate::spinlock::{pushcli, popcli}; + +/// Set up CPU's kernel segment descriptors. +/// Run once on entry on each CPU. +pub fn seginit() { + unsafe { + // Map "logical" addresses to virtual addresses using identity map. + let cpus = MP_ONCE.cpus.get().expect("CPUs not initialized"); + let cpu_ptr = cpus.as_ptr() as *mut crate::proc::Cpu; + let c = &mut *cpu_ptr.add(cpuid()); + + c.gdt[SEG_KCODE as usize] = SegDesc::seg(STA_X | STA_R, 0, 0xffffffff, 0); + c.gdt[SEG_KDATA as usize] = SegDesc::seg(STA_W, 0, 0xffffffff, 0); + lgdt(&c.gdt, size_of_val(&c.gdt)); + } +} + +pub fn switchuvm(p: *mut Proc) { + if p.is_null() { + panic!("switchuvm: no process"); + } + unsafe { + if (*p).kstack.is_null() { + panic!("switchuvm: no kstack"); + } + } + + pushcli(); + unsafe { + let c = mycpu(); + c.gdt[SEG_UCODE as usize] = + SegDesc::seg(STA_X | STA_R, (*p).offset as u32, (PROCSIZE << 12) - 1, DPL_USER); + c.gdt[SEG_UDATA as usize] = + SegDesc::seg(STA_W, (*p).offset as u32, (PROCSIZE << 12) - 1, DPL_USER); + lgdt(&c.gdt, size_of_val(&c.gdt)); + + c.gdt[SEG_TSS as usize] = SegDesc::seg16( + STS_T32A, + (&c.ts as *const _ as usize) as u32, + (size_of::() - 1) as u32, + 0, + ); + c.ts.ss0 = SEG_KDATA << 3; + c.ts.esp0 = ((*p).kstack as usize + KSTACKSIZE) as u32; + c.ts.iomb = 0xFFFF; + ltr(SEG_TSS << 3); + } + popcli(); +} diff --git a/src/x86.rs b/src/x86.rs index ba0598c..7713760 100644 --- a/src/x86.rs +++ b/src/x86.rs @@ -1,5 +1,7 @@ use core::arch::asm; use crate::traps::GateDesc; +use crate::mmu::SegDesc; +use crate::constants::NSEGS; pub fn inb(port: u16) -> u8 { let result: u8; @@ -25,19 +27,6 @@ pub fn outb(port: u16, value: u8) { } } -pub fn inw(port: u16) -> u16 { - let result: u16; - unsafe { - asm!( - "in ax, dx", - in("dx") port, - out("ax") result, - options(nomem, nostack) - ); - result - } -} - pub fn outw(port: u16, value: u16) { unsafe { asm!( @@ -49,41 +38,6 @@ pub fn outw(port: u16, value: u16) { } } -pub fn inl(port: u16) -> u32 { - unsafe { - let result: u32; - asm!( - "in eax, dx", - in("dx") port, - out("eax") result, - options(nomem, nostack) - ); - result - } -} - -pub fn outl(port: u16, value: u32) { - unsafe { - asm!( - "out dx, eax", - in("dx") port, - in("eax") value, - options(nomem, nostack) - ); - } -} - -pub fn readeflags() -> u32 { - unsafe { - let eflags: u32; - asm!( - "pushfd; pop eax", - out("eax") eflags, - options(nomem, nostack) - ); - eflags - } -} pub fn cli () { unsafe { @@ -112,6 +66,69 @@ pub fn lidt(gdt: *const [GateDesc; 256], size: usize) { } } +pub fn lgdt(gdt: *const [SegDesc; NSEGS], size: usize) { + let pd: [u16; 3] = [ + (size - 1) as u16, + (gdt as *const _) as u16, + ((gdt as *const _ as u32) >> 16) as u16, + ]; + unsafe { + asm!( + "lgdt [{0:e}]", + in(reg) (&pd as *const _ ) as u32, + options(nostack, readonly) + ); + } +} + +pub fn ltr(sel: u16) { + unsafe { + asm!("ltr {0:x}", in(reg) sel, options(nomem, nostack)); + } +} + +pub fn readeflags() -> u32 { + unsafe { + let eflags: u32; + asm!("pushfd; pop eax", out("eax") eflags, options(nomem, nostack)); + eflags + } +} + +pub fn noop() { + core::sync::atomic::compiler_fence(core::sync::atomic::Ordering::SeqCst); +} + +// x86.rs +pub unsafe fn insl(port: u16, addr: *mut u32, cnt: usize) { + core::arch::asm!( + "cld", + "rep insd", + in("dx") port, + inout("edi") (addr as usize) => _, + inout("ecx") cnt => _, + options(nostack, preserves_flags), + ); +} + + +// Output string of dwords to port using rep outsd instruction. +// Matches the C implementation: outsl(port, addr, cnt) +// Note: ESI must be saved/restored as LLVM restricts its use in 32-bit mode +pub unsafe fn outsl(port: u16, addr: *const u32, cnt: usize) { + let addr_val = addr as u32; + core::arch::asm!( + "push esi", + "mov esi, {addr}", + "cld", + "rep outsd", + "pop esi", + addr = in(reg) addr_val, + in("dx") port, + inout("ecx") cnt => _, + ); +} + /// Halts the CPU until the next interrupt occurs. /// The `hlt` instruction: /// 1. Stops instruction execution and places the processor in a HALT state @@ -136,6 +153,42 @@ pub fn rcr2() -> u32 { } } +pub fn stosb(addr: *mut u8, data: u8, cnt: usize) { + unsafe { + asm!( + "cld", + "rep stosb", + inout("edi") addr => _, + inout("ecx") cnt => _, + in("al") data, + options(nostack) + ); + } +} + +pub fn stosl(addr: *mut u32, data: u32, cnt: usize) { + unsafe { + asm!( + "cld", + "rep stosl", + inout("edi") addr => _, + inout("ecx") cnt => _, + in("eax") data, + options(nostack) + ); + } +} + +pub fn loadgs(v: u16) { + unsafe { + asm!( + "mov gs, {0:x}", + in(reg) v, + options(nomem, nostack) + ); + } +} + #[repr(C)] pub struct TrapFrame { // registers as pushed by pusha @@ -148,6 +201,15 @@ pub struct TrapFrame { pub ecx: u32, pub eax: u32, + // segment registers + pub gs: u16, + pub padding1: u16, + pub fs: u16, + pub padding2: u16, + pub es: u16, + pub padding3: u16, + pub ds: u16, + pub padding4: u16, pub trapno: u32, // below here defined by x86 hardware @@ -161,4 +223,37 @@ pub struct TrapFrame { pub esp: u32, pub ss: u16, pub padding6: u16, -} \ No newline at end of file +} + +// Page table/directory helper functions +use crate::constants::{PDXSHIFT, PTXSHIFT}; + +// Extract page directory index from virtual address +#[inline] +pub fn pdx(va: u32) -> usize { + ((va >> PDXSHIFT) & 0x3FF) as usize +} + +// Extract page table index from virtual address +#[inline] +pub fn ptx(va: u32) -> usize { + ((va >> PTXSHIFT) & 0x3FF) as usize +} + +// Construct virtual address from page directory index, page table index, and offset +#[inline] +pub fn pgaddr(d: u32, t: u32, o: u32) -> u32 { + (d << PDXSHIFT) | (t << PTXSHIFT) | o +} + +// Extract address from page table entry +#[inline] +pub fn pte_addr(pte: u32) -> u32 { + pte & !0xFFF +} + +// Extract flags from page table entry +#[inline] +pub fn pte_flags(pte: u32) -> u32 { + pte & 0xFFF +} diff --git a/swtch.S b/swtch.S new file mode 100644 index 0000000..60479ec --- /dev/null +++ b/swtch.S @@ -0,0 +1,22 @@ +# Context switch +# +# void swtch(struct context *new); +# +# Save the current registers on the stack, creating +# a struct context, and save its address in *old. +# Switch stacks to new and pop previously-saved registers. + +.globl swtch +swtch: + movl 4(%esp), %eax + + # Switch stacks + movl %eax, %esp + movl $0, %eax + + # Load new callee-saved registers + popl %edi + popl %esi + popl %ebx + popl %ebp + ret diff --git a/targets/i686.json b/targets/i686.json index 4cd8fa9..f72fa9a 100644 --- a/targets/i686.json +++ b/targets/i686.json @@ -13,4 +13,4 @@ "target-c-int-width": 32, "target-endian": "little", "target-pointer-width": 32 -} \ No newline at end of file +} diff --git a/trapasm.S b/trapasm.S index 414dc20..7f46ce1 100644 --- a/trapasm.S +++ b/trapasm.S @@ -4,8 +4,17 @@ .globl alltraps alltraps: # Build trap frame. + pushl %ds + pushl %es + pushl %fs + pushl %gs pushal + # Set up data segments. + movw $(SEG_KDATA<<3), %ax + movw %ax, %ds + movw %ax, %es + # Call trap(tf), where tf=%esp pushl %esp call trap @@ -15,5 +24,11 @@ alltraps: .globl trapret trapret: popal + popl %gs + popl %fs + popl %es + popl %ds addl $0x8, %esp # trapno and errcode iret + +.section .note.GNU-stack,"",@progbits \ No newline at end of file diff --git a/vectors.pl b/vectors.pl index 57b49dd..27d419b 100755 --- a/vectors.pl +++ b/vectors.pl @@ -26,6 +26,8 @@ print " .long vector$i\n"; } +print ".section .note.GNU-stack,\"\",%progbits\n"; + # sample output: # # handlers # .globl alltraps diff --git a/welcome.txt b/welcome.txt new file mode 100644 index 0000000..5809c82 --- /dev/null +++ b/welcome.txt @@ -0,0 +1,7 @@ + ### + # # ###### # #### #### # # ###### ### + # # # # # # # # ## ## # ### + # # ##### # # # # # ## # ##### # + # ## # # # # # # # # # + ## ## # # # # # # # # # ### + # # ###### ###### #### #### # # ###### ###