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shinyquagsire23 / bootstrap

ARM11 Kernel from ninjhax
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ARM11 Patching Does NOT support other firmware versions #1

Closed shinyquagsire23 closed 9 years ago

shinyquagsire23 commented 9 years ago

Currently we need offsets for the svc handler for versions 4.1-9.2 on all old 3DS kernels so that we can get the proper patching offsets to give us access to SVC 0x7B. The following code snippet demonstrates the patch needed:

ROM:FFF02244 loc_0_FFF02244                          ; CODE XREF: svc_handler+28j
ROM:FFF02244                 LDR     R8, [R8,R9,LSL#2]
ROM:FFF02248                 ADD     R10, SP, R9,LSR#3
ROM:FFF0224C                 MOV     R11, #1
ROM:FFF02250                 LDRB    R10, [R10,#0x20]
ROM:FFF02254                 AND     LR, R9, #7
ROM:FFF02258                 TST     R10, R11,LSL LR
ROM:FFF0225C                 LDRB    R10, [SP,#0x18+arg_18+1]
ROM:FFF02260                 BEQ     loc_0_FFF02210 <- change this to NOP
ROM:FFF02264                 CMP     R10, #0
ROM:FFF02268                 BEQ     loc_0_FFF022A4 <- and this one
ROM:FFF0226C                 MOV     LR, #0

Once the NOP is in place, the usermode app will be able to call SVC 0x7B and other previously unavailable SVCs.

We also need to make sure we patch back the original offsets properly, and find a proper offset for 4.x since the current offset is flawed.

shinyquagsire23 commented 9 years ago

All SVC patch offsets are now accounted for, now all that's left is getting 4.x working it seems and then testing.