blob: bb0b37023b0ff6c720c739d783ce3800f980b17a [file] [log] [blame]
/*
* Copyright (c) 2017 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
/* Include esp-idf headers first to avoid redefining BIT() macro */
#include "soc.h"
#include <soc/rtc_cntl_reg.h>
#include <soc/timer_group_reg.h>
#include <xtensa/config/core-isa.h>
#include <xtensa/corebits.h>
#include <kernel_structs.h>
#include <string.h>
#include <toolchain/gcc.h>
#include <zephyr/types.h>
extern void z_cstart(void);
/*
* This is written in C rather than assembly since, during the port bring up,
* Zephyr is being booted by the Espressif bootloader. With it, the C stack
* is already set up.
*/
void __attribute__((section(".iram1"))) __start(void)
{
volatile u32_t *wdt_rtc_reg = (u32_t *)RTC_CNTL_WDTCONFIG0_REG;
volatile u32_t *wdt_timg_reg = (u32_t *)TIMG_WDTCONFIG0_REG(0);
volatile u32_t *app_cpu_config_reg = (u32_t *)DPORT_APPCPU_CTRL_B_REG;
extern u32_t _init_start;
extern u32_t _bss_start;
extern u32_t _bss_end;
/* Move the exception vector table to IRAM. */
__asm__ __volatile__ (
"wsr %0, vecbase"
:
: "r"(&_init_start));
/* Zero out BSS. Clobber _bss_start to avoid memset() elision. */
(void)memset(&_bss_start, 0,
(&_bss_end - &_bss_start) * sizeof(_bss_start));
__asm__ __volatile__ (
""
:
: "g"(&_bss_start)
: "memory");
/* The watchdog timer is enabled in the bootloader. We're done booting,
* so disable it.
*/
*wdt_rtc_reg &= ~RTC_CNTL_WDT_FLASHBOOT_MOD_EN;
*wdt_timg_reg &= ~TIMG_WDT_FLASHBOOT_MOD_EN;
/* Disable normal interrupts. */
__asm__ __volatile__ (
"wsr %0, PS"
:
: "r"(PS_INTLEVEL(XCHAL_EXCM_LEVEL) | PS_UM | PS_WOE));
/* Disable CPU1 while we figure out how to have SMP in Zephyr. */
*app_cpu_config_reg &= ~DPORT_APPCPU_CLKGATE_EN;
/* Initialize the architecture CPU pointer. Some of the
* initialization code wants a valid _current before
* kernel_arch_init() is invoked.
*/
__asm__ volatile("wsr.MISC0 %0; rsync" : : "r"(&_kernel.cpus[0]));
/* Start Zephyr */
z_cstart();
CODE_UNREACHABLE;
}
/* Boot-time static default printk handler, possibly to be overriden later. */
int z_arch_printk_char_out(int c)
{
if (c == '\n') {
esp32_rom_uart_tx_one_char('\r');
}
esp32_rom_uart_tx_one_char(c);
return 0;
}