mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-12-18 12:28:09 +00:00
98e617d874
+ group confidential data in one place + zero all SRAM where needed
40 lines
1.1 KiB
ArmAsm
40 lines
1.1 KiB
ArmAsm
.syntax unified
|
|
|
|
.text
|
|
|
|
.global memset_reg
|
|
.type memset_reg, STT_FUNC
|
|
memset_reg:
|
|
// call with the following (note that the arguments are not validated prior to use):
|
|
// r0 - address of first word to write (inclusive)
|
|
// r1 - address of first word following the address in r0 to NOT write (exclusive)
|
|
// r2 - word value to be written
|
|
// both addresses in r0 and r1 needs to be divisible by 4!
|
|
.L_loop_begin:
|
|
str r2, [r0], 4 // store the word in r2 to the address in r0, post-indexed
|
|
cmp r0, r1
|
|
bne .L_loop_begin
|
|
bx lr
|
|
|
|
.global reset_handler
|
|
.type reset_handler, STT_FUNC
|
|
reset_handler:
|
|
ldr r0, =_ram_start // r0 - point to beginning of SRAM
|
|
ldr r1, =_ram_end // r1 - point to byte after the end of SRAM
|
|
ldr r2, =0 // r2 - the byte-sized value to be written
|
|
bl memset_reg
|
|
|
|
// copy .data section from flash to SRAM
|
|
ldr r0, =_data // dst addr
|
|
ldr r1, =_data_loadaddr // src addr
|
|
ldr r2, =_data_size // length in bytes
|
|
bl memcpy
|
|
|
|
// enter the application code
|
|
bl main
|
|
|
|
// loop forever if the application code returns
|
|
b .
|
|
|
|
.end
|