Add first syscall and migrate build script to python

.forgejo/workflows/build.yaml

@@ -5,7 +5,7 @@ jobs:
     runs-on: debian-12
     steps:
       - name: Install dependencies
-        run: apt-get update && apt-get install -y clang gcc-multilib llvm mtools parted udev
+        run: apt-get update && apt-get install -y clang gcc-multilib llvm mtools parted python3 udev
       - name: Install Rustup
         run: curl https://sh.rustup.rs | sh -s -- -y
       - name: Checkout
@@ -13,7 +13,7 @@ jobs:
         with:
           submodules: true
       - name: Build
-        run: . ~/.bashrc && ./build.sh
+        run: . ~/.bashrc && ./build.py
       - name: Install cargo-deny
         run: . ~/.bashrc && cargo install cargo-deny
       - name: Run cargo-deny

build.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python3
+import os
+import shutil
+import subprocess
+
+
+def run_command(cmd, cwd=None):
+    subprocess.run(cmd, shell=True, check=True, cwd=cwd)
+
+
+def main():
+    target = os.environ.get("OS_TARGET", "release")
+    if os.path.exists("img"):
+        shutil.rmtree("img")
+    os.makedirs("img/boot/efi/boot")
+
+    run_command("make -j4", cwd="lib/acpica-build")
+
+    components = ["init", "kernel", "loader"]
+    for component in components:
+        cargo_cmd = f'cargo build {"--release" if target == "release" else ""}'
+        run_command(cargo_cmd, cwd=component)
+
+    loader_path = f"target/x86_64-unknown-uefi/{target}/loader.efi"
+    shutil.copy(loader_path, "img/boot/efi/boot/bootx64.efi")
+
+    os.chdir("img")
+    run_command("dd if=/dev/zero of=boot.img bs=1M count=16 status=none")
+    run_command("mformat -i boot.img")
+    run_command("mcopy -si boot.img boot/* ::")
+
+    run_command("dd if=/dev/zero of=os.img bs=1M count=32 status=none")
+    run_command("parted -s os.img mklabel gpt")
+    run_command("parted -s os.img mkpart primary fat32 2048s 100%")
+    run_command("parted -s os.img set 1 esp on")
+    run_command("dd if=boot.img of=os.img bs=1M seek=1 conv=notrunc status=none")
+
+
+if __name__ == "__main__":
+    main()

build.sh

@@ -1,36 +0,0 @@
-#!/bin/bash
-set -euo pipefail
-target=${OS_TARGET:-release}
-rm -rf img
-mkdir -p img/boot/efi/boot
-cd lib/acpica-build
-make -j4
-cd ../../init
-if [ "$target" = "release" ]; then
-  cargo build --release
-else
-  cargo build
-fi
-cd ../kernel
-if [ "$target" = "release" ]; then
-  cargo build --release
-else
-  cargo build
-fi
-cd ../loader
-if [ "$target" = "release" ]; then
-  cargo build --release
-else
-  cargo build
-fi
-cd ..
-cp target/x86_64-unknown-uefi/$target/loader.efi img/boot/efi/boot/bootx64.efi
-cd img
-dd if=/dev/zero of=boot.img bs=1M count=16 status=none
-mformat -i boot.img
-mcopy -si boot.img boot/* ::
-dd if=/dev/zero of=os.img bs=1M count=32 status=none
-parted -s os.img mklabel gpt
-parted -s os.img mkpart primary fat32 2048s 100%
-parted -s os.img set 1 esp on
-dd if=boot.img of=os.img bs=1M seek=1 conv=notrunc status=none

kernel/src/cpu/isr.rs

@@ -4,7 +4,7 @@ use core::{
 };
 
 use kernel_common::instructions::hlt;
-use log::warn;
+use log::{debug, warn};
 
 use crate::{
     sys::{
@@ -12,7 +12,7 @@ use crate::{
         locks::Spinlock,
         scheduler::scheduler,
         sync::{IN_ISR_HANDLER, LOCKS_HELD},
-        task::terminate_current_task,
+        task::{TaskState, CURRENT_TASKS},
     },
     BROADCASTED_PANIC,
 };
@@ -113,8 +113,8 @@ extern "C" fn isr_handler(state: &mut ISRState) {
     IN_ISR_HANDLER[lapic_id].store(true, Ordering::SeqCst);
     if state.isr < 32 {
         if state.cs == 0x23 && state.isr != 2 && state.isr != 8 && state.isr != 18 {
-            warn!("Exception in usermode: {}", EXCEPTIONS[state.isr as usize]);
+            debug!("Exception in usermode: {}", EXCEPTIONS[state.isr as usize]);
-            terminate_current_task();
+            CURRENT_TASKS.lock()[get_current_lapic_id()].as_mut().unwrap().task_state = TaskState::Terminated;
             IN_ISR_HANDLER[lapic_id].store(false, Ordering::SeqCst);
             unsafe {
                 asm!("int $254");

kernel/src/cpu/syscall.s

@@ -8,26 +8,19 @@ syscall:
   swapgs
   sti
   push %r11
-  push %r10
-  push %r9
-  push %r8
-  push %rsi
-  push %rdi
-  push %rdx
   push %rcx
-  push %rax
+  mov %r10, %rcx
 
   call syscall_handler
 
-  pop %rax
   pop %rcx
-  pop %rdx
-  pop %rdi
-  pop %rsi
-  pop %r8
-  pop %r9
-  pop %r10
   pop %r11
+  xor %rdx, %rdx
+  xor %rdi, %rdi
+  xor %rsi, %rsi
+  xor %r8, %r8
+  xor %r9, %r9
+  xor %r10, %r10
   cli
   swapgs
   mov %gs:8, %rsp

kernel/src/sys/syscall.rs

@@ -1,2 +1,34 @@
+use log::debug;
+
+use super::task::terminate_current_task;
+
+struct SyscallArgs {
+    _arg1: usize,
+    _arg2: usize,
+    _arg3: usize,
+    _arg4: usize,
+    _arg5: usize,
+}
+
+const SYSCALL_TABLE: [fn(SyscallArgs) -> usize; 1] = [syscall_get_kernel_version];
+
+fn syscall_get_kernel_version(_args: SyscallArgs) -> usize {
+    0
+}
+
 #[no_mangle]
-extern "C" fn syscall_handler() {}
+extern "C" fn syscall_handler(syscall: u64, arg1: u64, arg2: u64, arg3: u64, arg4: u64, arg5: u64) -> u64 {
+    if syscall as usize >= SYSCALL_TABLE.len() {
+        debug!("Process requested invalid syscall");
+        terminate_current_task();
+    }
+    let args = SyscallArgs {
+        _arg1: arg1 as usize,
+        _arg2: arg2 as usize,
+        _arg3: arg3 as usize,
+        _arg4: arg4 as usize,
+        _arg5: arg5 as usize,
+    };
+    let result = SYSCALL_TABLE[syscall as usize](args);
+    result as u64
+}

kernel/src/sys/task.rs

@@ -145,8 +145,10 @@ fn create_idle_task() {
         IDLE_TASKS.lock().push(idle_task);
     }
 }
-pub fn terminate_current_task() {
+pub fn terminate_current_task() -> ! {
     CURRENT_TASKS.lock()[get_current_lapic_id()].as_mut().unwrap().task_state = TaskState::Terminated;
+    yield_task();
+    panic!("Failed to terminate task");
 }
 extern "C" fn task_entry() -> ! {
     let func;
@@ -156,8 +158,6 @@ extern "C" fn task_entry() -> ! {
     }
     func();
     terminate_current_task();
-    yield_task();
-    panic!("Failed to terminate task");
 }
 fn idle_main() {
     while !ALL_APS_STARTED.load(Ordering::SeqCst) {

qemu.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
 # shellcheck disable=SC2068
 set -euo pipefail
-./build.sh
+./build.py
 qemu-system-x86_64 -M q35 -accel kvm -cpu qemu64,rdrand,smap,smep,umip -smp 4 -m 256M -L /usr/share/OVMF -bios OVMF_CODE.fd -drive file=img/os.img,format=raw $@