arch/arm64/core/prep_c.c

/*
 * Copyright (c) 2019 Carlo Caione <ccaione@baylibre.com>
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @file
 * @brief Full C support initialization
 *
 * Initialization of full C support: zero the .bss and call z_cstart().
 *
 * Stack is available in this module, but not the global data/bss until their
 * initialization is performed.
 */

#include <kernel_internal.h>
#include <zephyr/linker/linker-defs.h>

__weak void z_arm64_mm_init(bool is_primary_core) { }

extern void z_arm64_mm_init(bool is_primary_core);

/*
 * These simple memset/memcpy alternatives are necessary as the optimized
 * ones depend on the MMU to be active (see commit c5b898743a20).
 */
void z_early_memset(void *dst, int c, size_t n)
{
	uint8_t *d = dst;

	while (n--) {
		*d++ = c;
	}
}

void z_early_memcpy(void *dst, const void *src, size_t n)
{
	uint8_t *d = dst;
	const uint8_t *s = src;

	while (n--) {
		*d++ = *s++;
	}
}

/**
 *
 * @brief Prepare to and run C code
 *
 * This routine prepares for the execution of and runs C code.
 *
 */
void z_arm64_prep_c(void)
{
	/* Initialize tpidrro_el0 with our struct _cpu instance address */
	write_tpidrro_el0((uintptr_t)&_kernel.cpus[0]);

	z_bss_zero();
	z_data_copy();
	z_arm64_mm_init(true);
	z_arm64_interrupt_init();
	z_cstart();

	CODE_UNREACHABLE;
}

#if CONFIG_MP_NUM_CPUS > 1
extern FUNC_NORETURN void z_arm64_secondary_start(void);
void z_arm64_secondary_prep_c(void)
{
	z_arm64_secondary_start();

	CODE_UNREACHABLE;
}
#endif