add basic support of the system calls 'fork' and 'spawn_process'#970
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stlankes wants to merge 10 commits into
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add basic support of the system calls 'fork' and 'spawn_process'#970stlankes wants to merge 10 commits into
stlankes wants to merge 10 commits into
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In the long term, Hermit will also be usable as a monolithic OS. To prepare for this, an example of calling the fork system call is being integrated. In the case of a unikernel, the fork call will return an error (ENOSYS).
Add the system call `spawn_process`, which creates a new process from the executable file.
In the long term, Hermit will also be usable as a monolithic OS. To prepare for this, an example of calling the fork system call is being integrated. In the case of a unikernel, the fork call will return an error (ENOSYS).
Replace all `-22` placeholders in the user-side syscall layer with real `syscall!` invocations and extend `SyscallNo` with the matching numbers (18–53) for spawn/join, file metadata, condvars, task blocking and the socket API.
- extend the fork example to test the system call `exec`
Mirrors hermit/src/syscall/x86_64.rs for the aarch64 target so that
common-os user-space binaries can issue syscalls into the kernel.
Convention follows the Linux-like AArch64 SVC ABI:
- svc #0 triggers the exception
- syscall number in x8 (input only)
- arguments in x0..x5 (up to six, like the existing macro)
- return value in x0 (`inlateout` for syscall1+, plain `lateout`
for syscall0)
- PSTATE.NZCV is preserved across the SVC, so options(preserves_flags)
is sound
The macro and the syscall0..syscall6 helper signatures match the x86_64
side verbatim, so the rest of the crate (sys_open, sys_read, sys_write,
sys_fork, sys_waitpid, …) compiles unchanged on aarch64.
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+ revert obsolete changes
- add a small benchmark to measure the overhead
Wires up the sys_mmap user-space stub (hermit_abi PROT_* flags, plumbing in syscall/mod.rs and Cargo.toml) and switches the Talck- based user heap from a 64 KiB static buffer to an mmap-backed heap that can grow on demand: - the first sys_malloc reserves an initial MIN_SIZE region via sys_mmap (anonymous, demand-paged), and HEAP_END tracks its current upper bound; - a later allocation that exceeds the existing heap extends the same VMA via sys_mmap(extend_size, …, &mut heap_end) and tells the allocator about the new region with ALLOC.extend(…).
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In the long term, Hermit will also be usable as a monolithic OS. To prepare for this, an example of calling the system calls
forkandspawn_processare being integrated. In the case of a unikernel, the fork call will return an error (ENOSYS).