SummerCart64/sw/controller/src/loader.S
2022-08-15 20:33:05 +02:00

100 lines
1.6 KiB
ArmAsm

.syntax unified
.cpu cortex-m0plus
.fpu softvfp
.thumb
.section .text.Reset_Handler
.type Reset_Handler, %function
Reset_Handler:
.global Reset_Handler
cpsid i
init_text:
ldr r0, =_stext
ldr r1, =_etext
ldr r2, =_sitext
bl copy_section
init_rodata:
ldr r0, =_srodata
ldr r1, =_erodata
ldr r2, =_sirodata
bl copy_section
init_data:
ldr r0, =_sdata
ldr r1, =_edata
ldr r2, =_sidata
bl copy_section
init_bss:
ldr r2, =_sbss
ldr r4, =_ebss
movs r3, #0
b 2f
1:
str r3, [r2]
adds r2, r2, #4
2:
cmp r2, r4
bcc 1b
run:
bl loader
boot:
ldr r0, =_app_magic
ldr r0, [r0]
ldr r1, =0x34364353
cmp r0, r1
bne empty_image
ldr r0, =_app_header
push {r0}
bl set_vector_table_offset
pop {r0}
ldr r1, [r0, #0]
msr MSP, r1
ldr r1, [r0, #4]
blx r1
empty_image:
bl no_valid_image
loop:
b loop
copy_section:
movs r3, #0
b 2f
1:
ldr r4, [r2, r3]
str r4, [r0, r3]
adds r3, r3, #4
2:
adds r4, r0, r3
cmp r4, r1
bcc 1b
bx lr
.section .text.Default_Handler, "ax", %progbits
Default_Handler:
.global Default_Handler
b Default_Handler
.section .isr_vector, "a", %progbits
.type g_pfnVectors, %object
g_pfnVectors:
.global g_pfnVectors
.word _estack
.word Reset_Handler
.word NMI_Handler
.word HardFault_Handler
.weak NMI_Handler
.thumb_set NMI_Handler, Default_Handler
.weak HardFault_Handler
.thumb_set HardFault_Handler, Default_Handler