/*
 * Copyright (C) 2023 Daniele Lacamera <root@danielinux.net>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdint.h>
#include "system.h"

extern uint32_t SystemCoreClock;
extern uint32_t _start_heap;

static void flash_set_waitstates(int waitstates)
{
    FLASH_ACR |=  waitstates | FLASH_ACR_ENABLE_DATA_CACHE | FLASH_ACR_ENABLE_INST_CACHE;
}

void clock_pll_off(void)
{
    uint32_t reg32;
    /* Enable internal high-speed oscillator. */
    RCC_CR |= RCC_CR_HSION;
    DMB();
    while ((RCC_CR & RCC_CR_HSIRDY) == 0) {};

    /* Select HSI as SYSCLK source. */
    reg32 = RCC_CFGR;
    reg32 &= ~((1 << 1) | (1 << 0));
    RCC_CFGR = (reg32 | RCC_CFGR_SW_HSI);
    DMB();

    /* Turn off PLL */
    RCC_CR &= ~RCC_CR_PLLON;
    DMB();
}

#include <string.h>
/*
size_t strlen(const char *s)
{
    int i = 0;

    while (s[i] != 0)
        i++;

    return i;
}
*/

void * _sbrk(unsigned int incr)
{
    static unsigned char *heap = (unsigned char *)&_start_heap;
    void *old_heap = heap;
    if (((incr >> 2) << 2) != incr)
        incr = ((incr >> 2) + 1) << 2;

    if (heap == NULL)
		heap = (unsigned char *)&_start_heap;
	else
        heap += incr;
    return old_heap;
}