src/lib/loaders/load_and_run_payload.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2014 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.
 */

#include <stdint.h>
#include <stdlib.h>
#include <cbmem.h>
#include <console/console.h>
#include <fallback.h>
#include <lib.h>
#include <program_loading.h>
#include <symbols.h>
#include <timestamp.h>

extern const struct prog_loader_ops vboot_loader;
extern const struct prog_loader_ops cbfs_payload_loader;

static const struct prog_loader_ops *payload_ops[] = {
#if CONFIG_VBOOT_VERIFY_FIRMWARE
	&vboot_loader,
#endif
	&cbfs_payload_loader,
};

static struct prog global_payload = {
	.name = CONFIG_CBFS_PREFIX "/payload",
	.type = PROG_PAYLOAD,
};

void __attribute__((weak)) mirror_payload(struct prog *payload)
{
	return;
}

void payload_load(void)
{
	int i;
	const struct prog_loader_ops *ops;
	struct prog *payload = &global_payload;

	for (i = 0; i < ARRAY_SIZE(payload_ops); i++) {
		/* Default loader state is active. */
		int ret = 1;

		ops = payload_ops[i];

		if (ops->is_loader_active != NULL)
			ret = ops->is_loader_active(payload);

		if (ret == 0) {
			printk(BIOS_DEBUG, "%s payload loader inactive.\n",
				ops->name);
			continue;
		} else if (ret < 0) {
			printk(BIOS_DEBUG, "%s payload loader failure.\n",
				ops->name);
			continue;
		}

		if (ops->prepare(payload) < 0) {
			printk(BIOS_DEBUG, "%s: could not locate payload.\n",
				ops->name);
			continue;
		}
		printk(BIOS_DEBUG, "%s: located payload @ %p, %zu bytes.\n",
			ops->name, prog_start(payload), prog_size(payload));
		break;
	}

	if (i == ARRAY_SIZE(payload_ops))
		goto out;

	mirror_payload(payload);

	/* Pass cbtables to payload if architecture desires it. */
	prog_set_entry(payload, selfload(payload),
			cbmem_find(CBMEM_ID_CBTABLE));

out:
	if (prog_entry(payload) == NULL)
		die("Payload not loaded.\n");
}

void payload_run(void)
{
	struct prog *payload = &global_payload;

	/* Reset to booting from this image as late as possible */
	boot_successful();

	printk(BIOS_DEBUG, "Jumping to boot code at %p(%p)\n",
		prog_entry(payload), prog_entry_arg(payload));
	post_code(POST_ENTER_ELF_BOOT);

	timestamp_add_now(TS_SELFBOOT_JUMP);

	/* Before we go off to run the payload, see if
	 * we stayed within our bounds.
	 */
	checkstack(_estack, 0);

	prog_run(payload);
}