mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-11-22 23:48:12 +00:00
108 lines
3.5 KiB
ArmAsm
108 lines
3.5 KiB
ArmAsm
.syntax unified
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.text
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.global reset_handler
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.type reset_handler, STT_FUNC
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reset_handler:
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// set the stack protection
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ldr r0, =_sstack
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add r0, r0, #16 // padding
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msr MSPLIM, r0
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bl SystemInit
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// read the first rng data and save it
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ldr r0, =0 // r0 - previous value
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ldr r1, =0 // r1 - whether to compare the previous value
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bl rng_read
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// read the next rng data and make sure it is different than previous
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// r0 - value returned from previous call
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ldr r1, =1 // r1 - whether to compare the previous value
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bl rng_read
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mov r4, r0 // save TRNG output in r4
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// wipe memory to remove any possible vestiges of sensitive data
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fill_ram:
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ldr r0, =sram1_start // r0 - point to beginning of SRAM
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ldr r1, =sram1_end // r1 - point to byte after the end of SRAM
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mov r2, r4 // r2 - the word-sized value to be written
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bl memset_reg
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ldr r0, =sram2_start // r0 - point to beginning of SRAM
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ldr r1, =sram2_end // r1 - point to byte after the end of SRAM
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mov r2, r4 // r2 - the word-sized value to be written
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bl memset_reg
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ldr r0, =sram3_start // r0 - point to beginning of SRAM
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ldr r1, =sram3_end // r1 - point to byte after the end of SRAM
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mov r2, r4 // r2 - the word-sized value to be written
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bl memset_reg
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ldr r0, =sram4_start // r0 - point to beginning of SRAM
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ldr r1, =sram4_end // r1 - point to byte after the end of SRAM
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mov r2, r4 // r2 - the word-sized value to be written
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bl memset_reg
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ldr r0, =sram5_start // r0 - point to beginning of SRAM
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ldr r1, =sram5_end // r1 - point to byte after the end of SRAM
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mov r2, r4 // r2 - the word-sized value to be written
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bl memset_reg
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ldr r0, =sram6_start // r0 - point to beginning of SRAM
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ldr r1, =sram6_end // r1 - point to byte after the end of SRAM
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mov r2, r4 // r2 - the word-sized value to be written
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bl memset_reg
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// setup environment for subsequent stage of code
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clear_ram:
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ldr r2, =0 // r2 - the word-sized value to be written
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ldr r0, =sram1_start // r0 - point to beginning of SRAM
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ldr r1, =sram1_end // r1 - point to byte after the end of SRAM
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bl memset_reg
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ldr r0, =sram2_start // r0 - point to beginning of SRAM
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ldr r1, =sram2_end // r1 - point to byte after the end of SRAM
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bl memset_reg
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ldr r0, =sram3_start // r0 - point to beginning of SRAM
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ldr r1, =sram3_end // r1 - point to byte after the end of SRAM
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bl memset_reg
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ldr r0, =sram4_start // r0 - point to beginning of SRAM
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ldr r1, =sram4_end // r1 - point to byte after the end of SRAM
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bl memset_reg
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ldr r0, =sram5_start // r0 - point to beginning of SRAM
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ldr r1, =sram5_end // r1 - point to byte after the end of SRAM
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bl memset_reg
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ldr r0, =sram6_start // r0 - point to beginning of SRAM
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ldr r1, =sram6_end // r1 - point to byte after the end of SRAM
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bl memset_reg
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// copy data in from flash
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ldr r0, =data_vma // dst addr
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ldr r1, =data_lma // src addr
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ldr r2, =data_size // size in bytes
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bl memcpy
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// copy sensitive data in from flash
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ldr r0, =sensitive_vma // dst addr
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ldr r1, =sensitive_lma // src addr
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ldr r2, =sensitive_size // size in bytes
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bl memcpy
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// setup the stack protector (see build script "-fstack-protector-all") with an unpredictable value
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bl rng_get
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ldr r1, = __stack_chk_guard
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str r0, [r1]
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// enter the application code
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bl main
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b shutdown_privileged
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.end
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