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Fix fs patch to work on old FIRMs

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Aurora 2016-10-15 15:04:48 +02:00
parent a795a45c34
commit 3b7b66b272
1 changed files with 40 additions and 36 deletions
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76
patches/k11modules.s
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@ -35,66 +35,70 @@
; Register contents:
; r4: Pointer to a pointer to the exheader of the current NCCH
; r6: Constant 0
; SP + 0x80 - 0x7C: Pointer to the memory location where the NCCH text was loaded
; SP + 4: Pointer to the memory location where the NCCH text was loaded
; Execute the instruction we overwrote in our detour
ldr r0, [r4]
; Save the value of the register we use
push {r1-r4}
push {r0-r4}
ldr r0, [sp, #20] ; Load the .text address
ldr r1, [r4]
ldr r2, [r1, #0x200] ; Load the low title id of the current NCCH
ldr r1, [r1, #0x18] ; Load the size of the .text
add r1, r0, r1 ; Max bounds of the memory region
ldr r1, [sp, #24] ; Load the .text address
ldr r2, [r0, #0x200] ; Load the low title id of the current NCCH
ldr r0, [r0, #0x18] ; Load the size of the .text
add r0, r1, r0 ; Max bounds of the memory region
ldr r3, =0x1002 ; Low title id of the sm module
cmp r2, r3 ; Compare the low title id to the id of the sm module
bne fs_patch ; Skip if they're not the same
ldr r3, =0x1002 ; Low title id of the sm module
cmp r2, r3 ; Compare the low title id to the id of the sm module
bne fs_patch ; Skip if they're not the same
ldr r2, =0xE1A01006 ; mov r1, r6
ldr r2, =0xE1A01006 ; mov r1, r6
loop:
cmp r1, r0
blo out ; Check if we didn't go past the bounds of the memory region
ldr r3, [r0]
cmp r0, r1
blo die ; Check if we didn't go past the bounds of the memory region
ldr r3, [r1]
cmp r3, r2
ldreqh r3, [r0, #4]
ldreqh r3, [r1, #4]
cmpeq r3, #5
addne r0, #4
addne r1, #4
bne loop
; r0 now contains the start address of the pattern we found
ldr r1, =0xE3A00001 ; mov r0, #1
str r1, [r0, #8] ; Patch the bl
; r1 now contains the start address of the pattern we found
ldr r0, =0xE3A00001 ; mov r0, #1
str r0, [r1, #8] ; Patch the bl
b out
fs_patch: ; patch adapted from BootNTR
ldr r3, =0x1102 ; Low title id of the fs module
cmp r2, r3 ; Compare the low title id to the id of the sm module
bne out ; Skip if they're not the same
ldr r2, =0x4618 ; mov r0, r3
ldr r3, =0x3481 ; add r4, #0x81
cmp r2, r3 ; Compare the low title id to the id of the sm module
bne out ; Skip if they're not the same
ldr r2, =0x7401 ; strb r1, [r0, #16]
ldr r3, =0x2000 ; movs r0, #0
loop_fs:
cmp r1, r0
blo out
ldrh r4, [r0]
cmp r0, r1
blo die
ldrh r4, [r1]
cmp r4, r2
ldreqh r4, [r0, #2]
ldreqh r4, [r1, #2]
cmpeq r4, r3
subeq r0, #8
addne r0, #2
addeq r1, #8
addne r1, #2
bne loop_fs
; r0 now contains the start address of the pattern we found
ldr r1, =0x2001 ; mov r0, #1
; r1 now contains the start address of the pattern we found
ldr r0, =0x2001 ; mov r0, #1
ldr r2, =0x4770 ; bx lr
strh r1, [r0]
strh r2, [r0, #2]
strh r0, [r1]
strh r2, [r1, #2]
out:
pop {r1-r4} ; Restore the registers we used
ldr r0, [r4] ; Execute the instruction we overwrote in our detour
bx lr ; Jump back to whoever called us
pop {r0-r4} ; Restore the registers we used
bx lr ; Jump back to whoever called us
die:
b die
.pool
.close