aboutsummaryrefslogtreecommitdiff
path: root/src/lib/libc/setjmp.s
diff options
context:
space:
mode:
authorAlex Auvolat <alex@adnab.me>2016-07-16 18:07:24 +0200
committerAlex Auvolat <alex@adnab.me>2016-07-16 18:07:24 +0200
commitbb2dd23f315bafa7b0b64845c2fe25d7a0893b10 (patch)
tree51657cd1ad8b6f1d5941604e75c251a246809034 /src/lib/libc/setjmp.s
parent3d6a857b9186ef6304ea6cf04627c2b787169f29 (diff)
downloadkogata-bb2dd23f315bafa7b0b64845c2fe25d7a0893b10.tar.gz
kogata-bb2dd23f315bafa7b0b64845c2fe25d7a0893b10.zip
Got Lua running \o/
Diffstat (limited to 'src/lib/libc/setjmp.s')
-rw-r--r--src/lib/libc/setjmp.s75
1 files changed, 34 insertions, 41 deletions
diff --git a/src/lib/libc/setjmp.s b/src/lib/libc/setjmp.s
index 164cc5b..a9b5f48 100644
--- a/src/lib/libc/setjmp.s
+++ b/src/lib/libc/setjmp.s
@@ -1,24 +1,18 @@
[GLOBAL setjmp]
setjmp:
- ; Store general purpose registers
- ; (in new stack frame)
- mov [esp+4], eax
- mov [esp+8], ebx
- mov [esp+12], ecx
- mov [esp+16], edx
- mov [esp+20], edi
- mov [esp+24], esi
- mov [esp+28], ebp
- mov [esp+32], esp
-
- ; Store flags
- pushf
- pop eax
- mov [esp+36], eax
+ ; get return address
+ mov edx, [esp]
+ ; get address of jmpbuf structure
+ mov ecx, [esp+4]
- ; Store return address
- mov eax, [esp]
- mov [esp+40], eax
+ ; Store general purpose registers
+ mov [ecx], ebx
+ mov [ecx+4], edx
+ mov [ecx+8], ebp
+ mov [ecx+12], esp
+ mov [ecx+16], esi
+ mov [ecx+20], edi
+ mov [ecx+24], eax
; return 0
xor eax, eax
@@ -27,27 +21,26 @@ setjmp:
[GLOBAL longjmp]
longjmp:
- ; on previous stack, resume return address
- mov eax, [esp+32]
- mov ebx, [esp+40]
- mov [eax], ebx
-
- ; resume flags
- mov eax, [esp+36]
- push eax
- popf
-
- ; load return value in eax
- mov eax, [esp+44]
- ; resume geneal purpose registers, except eax/esp
- mov ebx, [esp+8]
- mov ecx, [esp+12]
- mov edx, [esp+16]
- mov edi, [esp+20]
- mov esi, [esp+24]
- mov ebp, [esp+28]
-
- ; resume previous esp
- mov esp, [esp+32]
- ; return as if we were the setjmp call
+ ; get address of jmpbuf structure
+ mov ecx, [esp+4]
+ ; get retun value
+ mov eax, [esp+8]
+
+ ; load general purpose registers
+ ; (edx contains the return address)
+ mov ebx, [ecx]
+ mov edx, [ecx+4]
+ mov ebp, [ecx+8]
+ mov esp, [ecx+12]
+ mov esi, [ecx+16]
+ mov edi, [ecx+20]
+
+ ; make sure return value is nonzero
+ test eax, eax
+ jnz _doret
+ inc eax
+_doret:
+ ; store back return address
+ mov [esp], edx
ret
+