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dump-rom-usb.S
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dump-rom-usb.S
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.text
.global _start
_start:
disable_interrupts:
mrs r0, cpsr
mov r1, #0xc0
orr r0, r0, r1
msr cpsr_cxsf, r0
relocate_stack:
ldr r0, =0x70009ffc // stack_start
mov sp, r0
dump_memory:
bl output_newline
ldr r7, =0xfff00000 // start address
add r8, r7, #0x8800 // count
mov r5, #0
encode_hex_loop:
# hex encoding borrowed from gcc output:
ldrb r2, [r7], #1
mov r1, r2, lsr #4
add r1, r1, #48
and r2, r2, #15
add r2, r2, #48
cmp r1, #57
addhi r1, r1, #39
cmp r2, #57
addhi r2, r2, #39
adr r0, hex_msg
strb r1, [r0, #1]
strb r2, [r0, #2]
bl output_hex
add r5, r5, #1
tst r5, #15
bleq output_newline
cmp r7, r8
bne encode_hex_loop
bl output_banner
bl reboot
error:
b error
output_hex:
adr r0, hex_msg
mov r1, #6
b usb_out
output_banner:
adr r0, fake_banner
mov r1, #11
b usb_out
output_newline:
adr r0, newline_msg
mov r1, #1
usb_out:
push {lr}
# void usb_uart_write(char *data, int bytes, int timeout)
ldr r3, =0xfff00b7f
blx r3
# void usb_uart_flush(void)
ldr r3, =0xfff01cb1
blx r3
pop {lr}
bx lr
// trigger WDT reboot
reboot:
ldr r0, =0xa003001c
ldr r1, =0x1209
str r1, [r0]
bx lr // shouldn't get here
hex_msg: .asciz "\"xx\", "
newline_msg: .asciz "\n"
fake_banner: .asciz "# >"