chore(core/embed): remove unused code

[no changelog]

core/embed/bootloader/main.c

@@ -348,9 +348,6 @@ void real_jump_to_firmware(void) {
   display_finish_actions();
   ensure_compatible_settings();
 
-  // mpu_config_firmware();
-  // jump_to_unprivileged(FIRMWARE_START + vhdr.hdrlen + IMAGE_HEADER_SIZE);
-
   mpu_config_off();
   jump_to(FIRMWARE_START + vhdr.hdrlen + IMAGE_HEADER_SIZE);
 }

core/embed/bootloader_ci/main.c

@@ -293,9 +293,6 @@ int main(void) {
 
   // do not check any trust flags on header, proceed
 
-  // mpu_config_firmware();
-  // jump_to_unprivileged(FIRMWARE_START + vhdr.hdrlen + IMAGE_HEADER_SIZE);
-
   mpu_config_off();
   jump_to(FIRMWARE_START + vhdr.hdrlen + IMAGE_HEADER_SIZE);
 

core/embed/trezorhal/stm32f4/platform.h

@@ -34,7 +34,6 @@ void set_core_clock(clock_settings_t settings);
 
 void memset_reg(volatile void *start, volatile void *stop, uint32_t val);
 void jump_to(uint32_t address);
-void jump_to_unprivileged(uint32_t address);
 void jump_to_with_flag(uint32_t address, uint32_t register_flag);
 void ensure_compatible_settings(void);
 void clear_otg_hs_memory(void);

core/embed/trezorhal/stm32f4/util.s

@@ -77,61 +77,6 @@ jump_to_with_flag:
   ldr lr, [lr, 4]       // set lr to the next stage's reset_handler
   bx lr
 
-  .global jump_to_unprivileged
-  .type jump_to_unprivileged, STT_FUNC
-jump_to_unprivileged:
-  mov r4, r0            // save input argument r0 (the address of the next stage's vector table) (r4 is callee save)
-  // this subroutine re-points the exception handlers before the C code
-  // that comprises them has been given a good environment to run.
-  // therefore, this code needs to disable interrupts before the VTOR
-  // update. then, the reset_handler of the next stage needs to re-enable interrupts.
-  // the following prevents activation of all exceptions except Non-Maskable Interrupt (NMI).
-  // according to "ARM Cortex-M Programming Guide to Memory Barrier Instructions" Application Note 321, section 4.8:
-  // "there is no requirement to insert memory barrier instructions after CPSID".
-  cpsid f
-  // wipe memory at the end of the current stage of code
-  bl clear_otg_hs_memory
-  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
-  mov lr, r4
-  // clear out the general purpose registers before the next stage's code can run (even the NMI exception handler)
-  ldr r0, =0
-  mov r1, r0
-  mov r2, r0
-  mov r3, r0
-  mov r4, r0
-  mov r5, r0
-  mov r6, r0
-  mov r7, r0
-  mov r8, r0
-  mov r9, r0
-  mov r10, r0
-  mov r11, r0
-  mov r12, r0
-  // give the next stage a fresh main stack pointer
-  ldr r0, [lr]          // set r0 to the main stack pointer in the next stage's vector table
-  msr msp, r0           // give the next stage its main stack pointer
-  // point to the next stage's exception handlers
-  // AN321, section 4.11: "a memory barrier is not required after a VTOR update"
-  .set SCB_VTOR, 0xE000ED08 // reference "Cortex-M4 Devices Generic User Guide" section 4.3
-  ldr r0, =SCB_VTOR
-  str lr, [r0]
-  mov r0, r1            // zero out r0
-  // go on to the next stage
-  ldr lr, [lr, 4]       // set lr to the next stage's reset_handler
-  // switch to unprivileged mode
-  ldr r0, =1
-  msr control, r0
-  isb
-  // jump
-  bx lr
-
   .global shutdown_privileged
   .type shutdown_privileged, STT_FUNC
   // The function must be called from the privileged mode

core/embed/trezorhal/stm32u5/limited_util.s

@@ -53,8 +53,9 @@ jump_to:
   ldr r0, =__fb_end      // r0 - point to end of framebuffer
   ldr r1, =sram5_end     // r1 - point to byte after the end of SRAM
   bl memset_reg
+
   mov lr, r4
-  // clear out the general purpose registers before the next stage's code can run (even the NMI exception handler)
+  // clear out the general purpose registers before the next stage's code can run
   ldr r0, =0
   mov r1, r0
   mov r2, r0
@@ -81,7 +82,6 @@ jump_to:
   ldr lr, [lr, 4]       // set lr to the next stage's reset_handler
   bx lr
 
-
   .global shutdown_privileged
   .type shutdown_privileged, STT_FUNC
   // The function must be called from the privileged mode

core/embed/trezorhal/stm32u5/platform.h

@@ -40,7 +40,6 @@ void drop_privileges(void);
 // the following functions are defined in util.s
 void memset_reg(volatile void *start, volatile void *stop, uint32_t val);
 void jump_to(uint32_t address);
-void jump_to_unprivileged(uint32_t address);
 void jump_to_with_flag(uint32_t address, uint32_t register_flag);
 
 extern uint32_t __stack_chk_guard;

core/embed/trezorhal/stm32u5/util.s

@@ -58,7 +58,7 @@ jump_to:
   bl memset_reg
 
   mov lr, r4
-  // clear out the general purpose registers before the next stage's except the register with flag R11
+  // clear out the general purpose registers before the next stage's code can run
   ldr r0, =0
   mov r1, r0
   mov r2, r0
@@ -85,74 +85,6 @@ jump_to:
   ldr lr, [lr, 4]       // set lr to the next stage's reset_handler
   bx lr
 
-  .global jump_to_unprivileged
-  .type jump_to_unprivileged, STT_FUNC
-jump_to_unprivileged:
-  mov r4, r0            // save input argument r0 (the address of the next stage's vector table) (r4 is callee save)
-  // this subroutine re-points the exception handlers before the C code
-  // that comprises them has been given a good environment to run.
-  // therefore, this code needs to disable interrupts before the VTOR
-  // update. then, the reset_handler of the next stage needs to re-enable interrupts.
-  // the following prevents activation of all exceptions except Non-Maskable Interrupt (NMI).
-  // according to "ARM Cortex-M Programming Guide to Memory Barrier Instructions" Application Note 321, section 4.8:
-  // "there is no requirement to insert memory barrier instructions after CPSID".
-  cpsid f
-  // wipe memory at the end of the current stage of code
-  ldr r2, =0             // r2 - the word-sized value to be written
-  ldr r0, =sram1_start   // r0 - point to beginning of SRAM
-  ldr r1, =sram1_end     // r1 - point to byte after the end of SRAM
-  bl memset_reg
-  ldr r0, =sram2_start   // r0 - point to beginning of SRAM
-  ldr r1, =sram2_end     // r1 - point to byte after the end of SRAM
-  bl memset_reg
-  ldr r0, =sram4_start   // r0 - point to beginning of SRAM
-  ldr r1, =sram4_end     // r1 - point to byte after the end of SRAM
-  bl memset_reg
-  ldr r0, =sram6_start   // r0 - point to beginning of SRAM
-  ldr r1, =sram6_end     // r1 - point to byte after the end of SRAM
-  bl memset_reg
-  ldr r0, =boot_args_start   // r0 - point to beginning of boot args
-  ldr r1, =boot_args_end     // r1 - point to byte after the end of boot args
-  bl memset_reg
-  ldr r0, =sram3_start   // r0 - point to beginning of SRAM
-  ldr r1, =__fb_start    // r1 - point to beginning of framebuffer
-  bl memset_reg
-  ldr r0, =__fb_end      // r0 - point to end of framebuffer
-  ldr r1, =sram5_end     // r1 - point to byte after the end of SRAM
-  bl memset_reg
-  mov lr, r4
-  // clear out the general purpose registers before the next stage's code can run (even the NMI exception handler)
-  ldr r0, =0
-  mov r1, r0
-  mov r2, r0
-  mov r3, r0
-  mov r4, r0
-  mov r5, r0
-  mov r6, r0
-  mov r7, r0
-  mov r8, r0
-  mov r9, r0
-  mov r10, r0
-  mov r11, r0
-  mov r12, r0
-  // give the next stage a fresh main stack pointer
-  ldr r0, [lr]          // set r0 to the main stack pointer in the next stage's vector table
-  msr msp, r0           // give the next stage its main stack pointer
-  // point to the next stage's exception handlers
-  // AN321, section 4.11: "a memory barrier is not required after a VTOR update"
-  .set SCB_VTOR, 0xE000ED08 // reference "Cortex-M4 Devices Generic User Guide" section 4.3
-  ldr r0, =SCB_VTOR
-  str lr, [r0]
-  mov r0, r1            // zero out r0
-  // go on to the next stage
-  ldr lr, [lr, 4]       // set lr to the next stage's reset_handler
-  // switch to unprivileged mode
-  ldr r0, =1
-  msr control, r0
-  isb
-  // jump
-  bx lr
-
   .global shutdown_privileged
   .type shutdown_privileged, STT_FUNC
   // The function must be called from the privileged mode