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Atmosphere/emummc/source/nx/start.s
2019-06-16 11:09:02 -07:00

131 lines
2.4 KiB
ArmAsm

/**
* @file start.s
* @copyright libnx Authors
*/
.macro push_all
SUB SP, SP, #0x100
STP X29, X30, [SP, #0x0]
STP X27, X28, [SP, #0x10]
STP X25, X26, [SP, #0x20]
STP X23, X24, [SP, #0x30]
STP X21, X22, [SP, #0x40]
STP X19, X20, [SP, #0x50]
STP X17, X18, [SP, #0x60]
STP X15, X16, [SP, #0x70]
STP X13, X14, [SP, #0x80]
STP X11, X12, [SP, #0x90]
STP X9, X10, [SP, #0xA0]
STP X7, X8, [SP, #0xB0]
STP X5, X6, [SP, #0xC0]
STP X3, X4, [SP, #0xD0]
STP X1, X2, [SP, #0xE0]
STR X0, [SP, #0xF0]
.endm
.macro pop_all
LDR X0, [SP, #0xF0]
LDP X1, X2, [SP, #0xE0]
LDP X3, X4, [SP, #0xD0]
LDP X5, X6, [SP, #0xC0]
LDP X7, X8, [SP, #0xB0]
LDP X9, X10, [SP, #0xA0]
LDP X11, X12, [SP, #0x90]
LDP X13, X14, [SP, #0x80]
LDP X15, X16, [SP, #0x70]
LDP X17, X18, [SP, #0x60]
LDP X19, X20, [SP, #0x50]
LDP X21, X22, [SP, #0x40]
LDP X23, X24, [SP, #0x30]
LDP X25, X26, [SP, #0x20]
LDP X27, X28, [SP, #0x10]
LDP X29, X30, [SP, #0x0]
ADD SP, SP, #0x100
.endm
.section ".crt0","ax"
.global _start
_start:
B startup
.org _start+0xc
B sdmmc_wrapper_read
.org _start+0x18
B sdmmc_wrapper_write
.org _start+0x80
.section ".crt0","ax"
startup:
# Save LR
MOV X7, X30
# Retrieve ASLR Base
BL +4
SUB X6, X30, #0x88
# Context Ptr and MainThread Handle
MOV X5, X0
MOV X4, X1
# Inject start
push_all
MOV W0, #0xFFFF8001
ADR X1, __rodata_start
ADR X2, __data_start
SUB X2, X2, X1
MOV X3, #1
SVC 0x73
MOV W0, #0xFFFF8001
ADR X1, __data_start
ADR X2, __argdata__
SUB X2, X2, X1
MOV X3, #3
SVC 0x73
pop_all
MOV X27, X7
MOV X25, X5
MOV X26, X4
# Clear .bss
ADRP X0, __bss_start__
ADRP X1, __bss_end__
ADD X0, X0, #:lo12:__bss_start__
ADD X1, X1, #:lo12:__bss_end__
SUB X1, X1, X0
ADD X1, X1, #7
BIC X1, X1, #7
bss_loop:
STR XZR, [X0], #8
SUBS X1, X1, #8
BNE bss_loop
# Store SP
MOV X1, SP
ADRP X0, __stack_top
STR X1, [X0, #:lo12:__stack_top]
# Process _DYNAMIC Section
MOV X0, X6
ADRP X1, _DYNAMIC
ADD X1, X1, #:lo12:_DYNAMIC
BL __nx_dynamic
# TODO: handle in code
MOV X0, X25
MOV X1, X26
MOV X2, X27
BL __initheap
BL __init
MOV X0, X25
MOV X1, X26
MOV X30, X27
# FS main
ADRP X16, __argdata__
BR X16