wip, thread support and timer

[ginge.git] / loader / emu_arm.s

diff --git a/loader/emu_arm.s b/loader/emu_arm.s
new file mode 100644 (file)
index 0000000..aa0d63f
--- /dev/null
+++ b/loader/emu_arm.s
@@ -0,0 +1,25 @@
+@ vim:filetype=armasm
+.text
+
+@ save registers and flags and call emu_handle_op
+@ r0 and r14 must be saved by caller, r0 is arg for handle_op
+@ on return everything is restored except lr, which is used to return
+
+.globl emu_call_handle_op
+emu_call_handle_op:
+    str   sp, [sp, #(-0xf00 + 4*13)]
+    sub   sp, sp, #0xf00
+    add   sp, sp, #4
+    stmia sp, {r1-r12}
+    sub   sp, sp, #4
+    mrs   r2, cpsr
+    mov   r1, sp
+    str   r2, [sp, #4*15]
+    mov   r4, lr
+    bl    emu_handle_op
+    ldr   r1, [sp, #4*15]
+    mov   lr, r4
+    msr   cpsr_f, r1
+    ldmia sp, {r0-r13}
+    bx    lr
+