1 files changed, 60 insertions, 0 deletions
diff --git a/kernel/asm.s b/kernel/asm.s
new file mode 100644
index 0000000..4abe607
--- /dev/null
+++ b/kernel/asm.s
@@ -0,0 +1,60 @@
+global switch_to
+extern ctask
+extern tss
+
+switch_to:
+  push ebp
+  mov ebp, esp
+  mov eax, [ebp+8]
+  mov [ctask], eax
+  mov esi, [ebp+12]
+  mov ecx, 13
+.loop:
+  lodsd
+  push eax
+  dec ecx
+  jz .end
+  jmp .loop
+.end:
+  mov ax, 0x23
+  mov ds, ax
+  mov es, ax
+  mov fs, ax
+  mov gs, ax
+  popa
+  iret
+
+; uint32_t ss;
+; uint32_t esp;
+; uint32_t eflags;
+; uint32_t cs;
+; uint32_t eip;
+; uint32_t eax;
+; uint32_t ecx;
+; uint32_t edx;
+; uint32_t ebx;
+; uint32_t esp_garbage;
+; uint32_t ebp;
+; uint32_t esi;
+; uint32_t edi;
+
+; switch_to:
+  ; push ebp
+  ; mov ebp, esp
+  ; cli
+  ; mov ax, 0x23
+  ; mov ds, ax
+  ; mov es, ax
+  ; mov fs, ax
+  ; mov gs, ax
+  ; mov eax, esp
+  ; ; save ESP in the TSS
+  ; mov [tss+4], eax
+  ; push dword 0x23
+  ; push dword 0x00180000
+  ; pushf
+  ; push dword 0x1B
+  ; push dword 0x00100000
+  ; iret
+  ; pop ebp
+  ; ret