elleoma/os-in-1000-lines
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

finish implementation of running multiple processes concurrently (unsafely)

Browse Source
This commit is contained in:
Amoelle
2025-07-23 15:52:18 +03:00
parent 1b45f68095
commit 954a379c2d
1 changed files with 11 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
kernel.c
View File

@@ -43,7 +43,9 @@ __attribute__((naked))
__attribute__((aligned(4))) __attribute__((aligned(4)))
void kernel_entry(void) { void kernel_entry(void) {
__asm__ __volatile__( __asm__ __volatile__(
"csrw sscratch, sp\n" // Retrieve the kernel stack of the running process from sscratch
"csrrw sp, sscratch, sp\n"
"addi sp, sp, -4 * 31\n" "addi sp, sp, -4 * 31\n"
"sw ra, 4 * 0(sp)\n" "sw ra, 4 * 0(sp)\n"
"sw gp, 4 * 1(sp)\n" "sw gp, 4 * 1(sp)\n"
@@ -76,9 +78,11 @@ void kernel_entry(void) {
"sw s10, 4 * 28(sp)\n" "sw s10, 4 * 28(sp)\n"
"sw s11, 4 * 29(sp)\n" "sw s11, 4 * 29(sp)\n"
// Retrieve and save the sp at the time of exception
"csrr a0, sscratch\n" "csrr a0, sscratch\n"
"sw a0, 4 * 30(sp)\n" "sw a0, 4 * 30(sp)\n"
// Reset the kernel stack
"mv a0, sp\n" "mv a0, sp\n"
"call handle_trap\n" "call handle_trap\n"
@@ -230,6 +234,12 @@ void yield(void) {
if (next == current_proc) if (next == current_proc)
return; return;
__asm__ __volatile__(
"csrw sscratch, %[sscratch]\n"
:
: [sscratch] "r" ((uint32_t) &next->stack[sizeof(next->stack)])
);
// Context switch // Context switch
struct process *prev = current_proc; struct process *prev = current_proc;
current_proc = next; current_proc = next;