try this....
Code:
stwu sp, -0x50 (sp)
stmw r16, 0x8 (sp)
lis r11, 0x8000
lmw r16, 0x0498 (r11)
lis r12, 0x8150
addi r22,r22,1
cmpwi r22,5 #XX value to modify
blt- 0xA8
cmpwi r19,0
bne- 0x0C
li r20,255
li r19,1
cmpwi r19,1
bne- 0x14
addi r16,r16,1
cmpwi r16,255
bne- 0x08
li r19,2
cmpwi r19,2
bne- 0x14
subi r20,r20,1
cmpwi r20,0
bne- 0x08
li r19,3
cmpwi r19,3
bne- 0x14
addi r17,r17,1
cmpwi r17,255
bne- 0x08
li r19,4
cmpwi r19,4
bne- 0x14
subi r16,r16,1
cmpwi r16,0
bne- 0x08
li r19,5
cmpwi r19,5
bne- 0x14
addi r20,r20,1
cmpwi r20,255
bne- 0x08
li r19,6
cmpwi r19,6
bne- 0x14
subi r17,r17,1
cmpwi r17,0
bne- 0x08
li r19,1
li r22,0
stb r20,0(r12)
stb r16,1(r12)
stb r17,2(r12)
stmw r16, 0x0498 (r11)
lmw r16, 0x8 (sp)
addi sp, sp, 0x50
cmpwi r0,0 #Default instruction