diff options
Diffstat (limited to 'docs/codehandler.s')
| -rw-r--r-- | docs/codehandler.s | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/docs/codehandler.s b/docs/codehandler.s index 0385c7605a..f80f22729c 100644 --- a/docs/codehandler.s +++ b/docs/codehandler.s @@ -21,6 +21,8 @@ #SOFTWARE.
#Based off of codehandleronly.s from Gecko OS source code.
+# Example command to build:
+# powerpc-elf-gcc -mpowerpc -mpaired -mbig codehandler.s -nostartfiles -nodefaultlibs -nostdlib -T codehandler.ld -o codehandler.bin
.text
#Register Defines
@@ -42,11 +44,11 @@ cheatdata: .space 39*4
_start:
- stwu r1,-168(r1) # stores sp
+ stwu r1,-172(r1) # stores sp
stw r0,8(r1) # stores r0
mflr r0
- stw r0,172(r1) # stores lr
+ stw r0,176(r1) # stores lr
mfcr r0
stw r0,12(r1) # stores cr
@@ -60,6 +62,8 @@ _start: stmw r3,24(r1) # saves r3-r31
mfmsr r25
+ stw r25,168(r1) # save msr
+
ori r26,r25,0x2000 #enable floating point ?
andi. r26,r26,0xF9FF
mtmsr r26
@@ -70,18 +74,17 @@ _start: - lis r31,_start@h #0x8000
+ lis r31,cheatdata@h #0x8000
lis r20, 0xCC00
lhz r28, 0x4010(r20)
ori r21, r28, 0xFF
sth r21, 0x4010(r20) # disable MP3 memory protection
- mflr r29
lis r15, codelist@h
ori r15, r15, codelist@l
- ori r7, 31, cheatdata@l # set pointer for storing data (before the codelist)
+ ori r7, r31, cheatdata@l # set pointer for storing data (before the codelist)
lis r6,0x8000 # default base address = 0x80000000 (code handler)
@@ -101,17 +104,16 @@ _start: addi r15,r15,8
b _readcodes
_exitcodehandler:
- mtlr r29
-resumegame:
sth r28,0x4010(r20) # restore memory protection value
lfd f2,152(r1) # loads f2
lfd f3,160(r1) # loads f3
+ lwz r25,168(r1)
mtmsr r25
- lwz r0,172(r1)
+ lwz r0,176(r1)
mtlr r0 # restores lr
lwz r0,12(r1)
@@ -127,7 +129,7 @@ resumegame: lwz r0,8(r1) # loads r0
- addi r1,r1,168
+ addi r1,r1,172
isync
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