P29 - Implement user-level shell with static allocation, console I/O, and syscall memory fixes#314
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sai-kaushik-s merged 2 commits intocodenet:p29-shellfrom Apr 13, 2026
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This PR introduces the foundational user-level shell (sh) for the xv6 operating system. Since malloc support is not yet available, the shell utilizes statically allocated buffers for command parsing and execution. This PR also wires up standard I/O descriptors, enables hardware keyboard interrupts for the console, and fixes critical memory translation bugs in system call argument fetching to account for the custom user process memory offsets.
Testing:
Successfully boots into user space via make qemu.
init successfully forks and executes sh.
Console displays the $ prompt and accepts keyboard input without freezing.
On writing any command, it outputs exec:fail, exec cat failed. Shell command functionality will be added in the next branch.