Improve scheduler

1 files changed, 46 insertions, 0 deletions

diff --git a/src/core/scheduler_asm.S b/src/core/scheduler_asm.S
new file mode 100644
index 0000000..92e3f2e
--- /dev/null
+++ b/src/core/scheduler_asm.S
@@ -0,0 +1,46 @@
+.globl task_switch
+
+// This function takes a pointer
+// to a PROC structure and jump
+// to this process
+task_switch:
+    push 12(%esi)  # eax (cf PROC struct)
+    push 16(%esi)  # ebx
+    push 20(%esi)  # ecx
+    push 24(%esi)  # edx
+    push 44(%esi)  # ebp
+    push 48(%esi)  # esi
+    push 52(%esi)  # edi
+    push 56(%esi)  # ds
+    push 60(%esi)  # es
+    push 64(%esi)  # fs
+    push 68(%esi)  # gs
+
+    // Don't forget to clear the interrupt
+    movb $0x20, %al
+    outb %al, $0x20
+
+    // Setup process page directory
+    mov 8(%esi), %eax
+    mov %eax, %cr3
+
+    // Setup registers
+    pop %gs
+    pop %fs
+    pop %es
+    pop %ds
+    pop %edi
+    pop %esi
+    pop %ebp
+    pop %edx
+    pop %ecx
+    pop %ebx
+    pop %eax
+
+    // Perform the task switch
+    push 36(%esi)  # ss
+    push 40(%esi)  # esp
+    push 72(%esi)  # eflags
+    push 28(%esi)  # cs
+    push 32(%esi)  # eip
+    iret