mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-11-08 16:42:03 +00:00
61 lines
1.9 KiB
ArmAsm
61 lines
1.9 KiB
ArmAsm
.syntax unified
|
|
|
|
.text
|
|
|
|
.global reset_handler
|
|
.type reset_handler, STT_FUNC
|
|
reset_handler:
|
|
bl SystemInit
|
|
|
|
// read the first rng data and save it
|
|
ldr r0, =0 // r0 - previous value
|
|
ldr r1, =0 // r1 - whether to compare the previous value
|
|
bl rng_read
|
|
|
|
// read the next rng data and make sure it is different than previous
|
|
// r0 - value returned from previous call
|
|
ldr r1, =1 // r1 - whether to compare the previous value
|
|
bl rng_read
|
|
mov r4, r0 // save TRNG output in r4
|
|
|
|
// wipe memory to remove any possible vestiges of sensitive data
|
|
// use unpredictable value as a defense against side-channels
|
|
ldr r0, =ccmram_start // r0 - point to beginning of CCMRAM
|
|
ldr r1, =ccmram_end // r1 - point to byte after the end of CCMRAM
|
|
mov r2, r4 // r2 - the word-sized value to be written
|
|
bl memset_reg
|
|
|
|
ldr r0, =sram_start // r0 - point to beginning of SRAM
|
|
ldr r1, =sram_end // r1 - point to byte after the end of SRAM
|
|
mov r2, r4 // r2 - the word-sized value to be written
|
|
bl memset_reg
|
|
|
|
// setup environment for subsequent stage of code
|
|
ldr r0, =ccmram_start // r0 - point to beginning of CCMRAM
|
|
ldr r1, =ccmram_end // r1 - point to byte after the end of CCMRAM
|
|
ldr r2, =0 // r2 - the word-sized value to be written
|
|
bl memset_reg
|
|
|
|
ldr r0, =sram_start // r0 - point to beginning of SRAM
|
|
ldr r1, =sram_end // r1 - point to byte after the end of SRAM
|
|
ldr r2, =0 // r2 - the word-sized value to be written
|
|
bl memset_reg
|
|
|
|
// copy data in from flash
|
|
ldr r0, =data_vma // dst addr
|
|
ldr r1, =data_lma // src addr
|
|
ldr r2, =data_size // size in bytes
|
|
bl memcpy
|
|
|
|
// setup the stack protector (see build script "-fstack-protector-all") with an unpredictable value
|
|
bl rng_get
|
|
ldr r1, = __stack_chk_guard
|
|
str r0, [r1]
|
|
|
|
// enter the application code
|
|
bl main
|
|
|
|
b shutdown_privileged
|
|
|
|
.end
|