#include "rcc.h"
#include "stm32.h"

void rcc_init() {
	// Set flash latency.
	FLASH.ACR = 0x12;
	
	// Enable HSE.
	RCC.CR |= 0x10000;
	while(RCC.CR & 0x20000);
	
	// Configure and enable PLL.
	RCC.CFGR = 0x1d0000;
	RCC.CR |= 0x1000000;
	while(RCC.CR & 0x2000000);
	
	// Switch to PLL.
	RCC.CFGR |= 0x2;
	while(!(RCC.CFGR & 0x8));
	
	// Set APB1 prescaler to /2.
	RCC.CFGR |= 0x400;
}