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/**
* @file init.c
* Kernel initialization procedure
*
* Copyright (C) 2018 Clyne Sullivan
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include "clock.h"
#include "gpio.h"
#include "heap.h"
#include "serial.h"
#include "task.h"
#include "vfs.h"
#include <fs/initrd.h>
#include <arch/stm/stm32l476xx.h>
// Heap goes after the end of the BSS section
extern uint8_t __bss_end__;
extern void user_main(void);
void init_idle(void);
int main(void)
{
// Disable interrupts while we get ready
asm("cpsid i");
// Disabling cached writes can help give more precise debug info
//*((uint32_t *)0xE000E008) |= 2;
// Prepare flash latency for 80MHz operation
FLASH->ACR &= ~(FLASH_ACR_LATENCY);
FLASH->ACR |= FLASH_ACR_LATENCY_4WS;
// Initialize core components
clock_init();
heap_init(&__bss_end__);
gpio_init();
serial_init(9600);
vfs_init();
initrd_init();
// Enable FPU (TODO why isn't it enabled?)
//SCB->CPACR |= (0xF << 20);
// Begin multi-tasking (enables interrupts)
task_init(init_idle, 512);
while (1);
}
void init_idle(void)
{
// Start the main userspace task with a 4kB stack
task_start(user_main, 4096);
// Idle
while (1)
clock_delay(10);
}
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