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trezor-firmware/embed/trezorhal/stm32.c
2017-10-11 23:11:59 +02:00

67 lines
3.0 KiB
C

#include STM32_HAL_H
#include "rng.h"
const uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};
const uint8_t APBPrescTable[8] = {0, 0, 0, 0, 1, 2, 3, 4};
uint32_t SystemCoreClock = 168000000;
void SystemInit(void)
{
// set flash wait states for an increasing HCLK frequency -- reference RM0090 section 3.5.1
FLASH->ACR = FLASH_ACR_LATENCY_5WS;
// configure main PLL; assumes HSE is 8 MHz; this should evaluate to 0x27402a04 -- reference RM0090 section 7.3.2
RCC->PLLCFGR = (RCC_PLLCFGR_RST_VALUE & ~RCC_PLLCFGR_PLLQ & ~RCC_PLLCFGR_PLLSRC & ~RCC_PLLCFGR_PLLP & ~RCC_PLLCFGR_PLLN & ~RCC_PLLCFGR_PLLM)
| (7 << RCC_PLLCFGR_PLLQ_Pos) // Q = 7
| RCC_PLLCFGR_PLLSRC_HSE // PLLSRC = HSE
| (0 << RCC_PLLCFGR_PLLP_Pos) // P = 2 (two bits, 00 means PLLP = 2)
| (168 << RCC_PLLCFGR_PLLN_Pos) // N = 168
| (4 << RCC_PLLCFGR_PLLM_Pos); // M = 4
// enable clock security system, HSE clock, and main PLL
RCC->CR |= RCC_CR_CSSON | RCC_CR_HSEON | RCC_CR_PLLON;
// wait until PLL and HSE ready
while((RCC->CR & (RCC_CR_PLLRDY | RCC_CR_HSERDY)) != (RCC_CR_PLLRDY | RCC_CR_HSERDY));
// APB2=2, APB1=4, AHB=1, system clock = main PLL
RCC->CFGR = RCC_CFGR_PPRE2_DIV2 | RCC_CFGR_PPRE1_DIV4 | RCC_CFGR_HPRE_DIV1 | RCC_CFGR_SW_PLL;
// wait until PLL is system clock
while((RCC->CFGR & RCC_CFGR_SWS) != RCC_CFGR_SWS_PLL);
// turn off the HSI as it is now unused (it will be turned on again automatically if a clock security failure occurs)
RCC->CR &= ~RCC_CR_HSION;
// init the TRNG peripheral
rng_init();
// enable full access to the fpu coprocessor
#if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2)); /* set CP10 and CP11 Full Access */
#endif
}
void SysTick_Handler(void) {
// Instead of calling HAL_IncTick we do the increment here of the counter.
// This is purely for efficiency, since SysTick is called 1000 times per
// second at the highest interrupt priority.
// Note: we don't need uwTick to be declared volatile here because this is
// the only place where it can be modified, and the code is more efficient
// without the volatile specifier.
extern uint32_t uwTick;
uwTick += 1;
// Read the systick control regster. This has the side effect of clearing
// the COUNTFLAG bit, which makes the logic in sys_tick_get_microseconds
// work properly.
SysTick->CTRL;
// Right now we have the storage and DMA controllers to process during
// this interrupt and we use custom dispatch handlers. If this needs to
// be generalised in the future then a dispatch table can be used as
// follows: ((void(*)(void))(systick_dispatch[uwTick & 0xf]))();
// if (STORAGE_IDLE_TICK(uwTick)) {
// NVIC->STIR = FLASH_IRQn;
// }
// if (DMA_IDLE_ENABLED() && DMA_IDLE_TICK(uwTick)) {
// dma_idle_handler(uwTick);
// }
}