src/arch/arm/stages.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright 2012 Google Inc.
 *
 * 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; version 2 of the License.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

/*
 * This file contains entry/exit functions for each stage during coreboot
 * execution (bootblock entry and ramstage exit will depend on external
 * loading.
 *
 * Unlike other files, this one should be compiled with a -m option to
 * specify a pre-determined instruction set. This is to ensure consistency
 * in the CPU operating mode (ARM or Thumb) when hand-off between stages
 * occurs.
 *
 * Entry points must be placed at the location the previous stage jumps
 * to (the lowest address in the stage image). This is done by giving
 * stage_entry() its own section in .text and placing it first in the
 * linker script.
 */

#include <arch/stages.h>
#include <arch/cache.h>

void stage_entry(void)
{
	main();
}

/* we had marked 'doit' as 'noreturn'.
 * There is no apparent harm in leaving it as something we can return from, and in the one
 * case where we call a payload, the payload is allowed to return.
 * Hence, leave it as something we can return from.
 */
void stage_exit(void *addr)
{
	void (*doit)(void) = addr;
	/* make sure any code we installed is written to memory. Not all ARM have
	 * unified caches.
	 */
	dcache_clean_all();
	/* Because most stages copy code to memory, it's a safe and hygienic thing
	 * to flush the icache here.
	 */
	icache_invalidate_all();
	doit();
}