cbfs: new API and better program loading

A new CBFS API is introduced to allow making CBFS access
easier for providing multiple CBFS sources. That is achieved
by decoupling the cbfs source from a CBFS file. A CBFS
source is described by a descriptor. It contains the necessary
properties for walking a CBFS to locate a file. The CBFS
file is then decoupled from the CBFS descriptor in that it's
no longer needed to access the contents of the file.

All of this is accomplished using the regions infrastructure
by repsenting CBFS sources and files as region_devices. Because
region_devices can be chained together forming subregions this
allows one to decouple a CBFS source from a file. This also allows
one to provide CBFS files that came from other sources for
payload and/or stage loading.

The program loading takes advantage of those very properties
by allowing multiple sources for locating a program. Because of
this we can reduce the overhead of loading programs because
it's all done in the common code paths. Only locating the
program is per source.

Change-Id: I339b84fce95f03d1dbb63a0f54a26be5eb07f7c8
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/9134
Tested-by: build bot (Jenkins)
Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

1 files changed, 247 insertions, 0 deletions

diff --git a/src/lib/prog_loaders.c b/src/lib/prog_loaders.c
new file mode 100644
index 0000000000..881cd99794
--- /dev/null
+++ b/src/lib/prog_loaders.c
@@ -0,0 +1,247 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 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 <stdlib.h>
+#include <arch/stages.h>
+#include <boot_device.h>
+#include <cbfs.h>
+#include <cbmem.h>
+#include <console/console.h>
+#include <fallback.h>
+#include <halt.h>
+#include <lib.h>
+#include <program_loading.h>
+#include <romstage_handoff.h>
+#include <rmodule.h>
+#include <rules.h>
+#include <stage_cache.h>
+#include <symbols.h>
+#include <timestamp.h>
+
+#define DEFAULT_CBFS_LOADER_PRESENT \
+	(!ENV_VERSTAGE || (ENV_VERSTAGE && !CONFIG_RETURN_FROM_VERSTAGE))
+
+#if DEFAULT_CBFS_LOADER_PRESENT
+static int cbfs_boot_prog_locate(struct prog *prog)
+{
+	return cbfs_boot_locate(&prog->rdev, prog->name, NULL);
+}
+
+static const struct prog_loader_ops cbfs_default_loader = {
+	.locate = cbfs_boot_prog_locate,
+};
+#endif
+
+extern const struct prog_loader_ops vboot_loader;
+
+static const struct prog_loader_ops *loaders[] = {
+#if CONFIG_VBOOT_VERIFY_FIRMWARE
+	&vboot_loader,
+#endif
+#if DEFAULT_CBFS_LOADER_PRESENT
+	&cbfs_default_loader,
+#endif
+};
+
+int prog_locate(struct prog *prog)
+{
+	int i;
+
+	boot_device_init();
+
+	for (i = 0; i < ARRAY_SIZE(loaders); i++) {
+		/* Default loader state is active. */
+		int ret = 1;
+		const struct prog_loader_ops *ops;
+
+		ops = loaders[i];
+
+		if (ops->is_loader_active != NULL)
+			ret = ops->is_loader_active(prog);
+
+		if (ret == 0) {
+			printk(BIOS_DEBUG, "%s loader inactive.\n",
+				ops->name);
+			continue;
+		} else if (ret < 0) {
+			printk(BIOS_DEBUG, "%s loader failure.\n",
+				ops->name);
+			continue;
+		}
+
+		printk(BIOS_DEBUG, "%s loader active.\n", ops->name);
+
+		if (ops->locate(prog))
+			continue;
+
+		printk(BIOS_DEBUG, "'%s' located at offset: %zx size: %zx\n",
+			prog->name, region_device_offset(&prog->rdev),
+			region_device_sz(&prog->rdev));
+
+		return 0;
+	}
+
+	return -1;
+}
+
+void run_romstage(void)
+{
+	struct prog romstage = {
+		.name = CONFIG_CBFS_PREFIX "/romstage",
+		.type = PROG_ROMSTAGE,
+	};
+
+	/* The only time the default CBFS loader isn't present is during
+	 * VERSTAGE in which it returns back to the calling stage. */
+	if (!DEFAULT_CBFS_LOADER_PRESENT)
+		return;
+
+	if (prog_locate(&romstage))
+		goto fail;
+
+	timestamp_add_now(TS_START_COPYROM);
+
+	if (cbfs_prog_stage_load(&romstage))
+		goto fail;
+
+	timestamp_add_now(TS_END_COPYROM);
+
+	prog_run(&romstage);
+
+fail:
+	if (IS_ENABLED(CONFIG_BOOTBLOCK_CONSOLE))
+		die("Couldn't load romstage.\n");
+	halt();
+}
+
+void __attribute__((weak)) stage_cache_add(int stage_id, struct prog *stage) {}
+void __attribute__((weak)) stage_cache_load_stage(int stage_id,
+							struct prog *stage) {}
+void __attribute__((weak)) ramstage_cache_invalid(void) {}
+
+static void run_ramstage_from_resume(struct romstage_handoff *handoff,
+					struct prog *ramstage)
+{
+	if (handoff != NULL && handoff->s3_resume) {
+		/* Load the cached ramstage to runtime location. */
+		stage_cache_load_stage(STAGE_RAMSTAGE, ramstage);
+
+		if (prog_entry(ramstage) != NULL) {
+			printk(BIOS_DEBUG, "Jumping to image.\n");
+			prog_run(ramstage);
+		}
+		ramstage_cache_invalid();
+	}
+}
+
+static int load_relocatable_ramstage(struct prog *ramstage)
+{
+	struct rmod_stage_load rmod_ram = {
+		.cbmem_id = CBMEM_ID_RAMSTAGE,
+		.prog = ramstage,
+	};
+
+	return rmodule_stage_load(&rmod_ram);
+}
+
+void run_ramstage(void)
+{
+	struct prog ramstage = {
+		.name = CONFIG_CBFS_PREFIX "/ramstage",
+		.type = PROG_RAMSTAGE,
+	};
+
+	/* Only x86 systems currently take the same firmware path on resume. */
+	if (IS_ENABLED(CONFIG_ARCH_X86) && IS_ENABLED(CONFIG_EARLY_CBMEM_INIT))
+		run_ramstage_from_resume(romstage_handoff_find_or_add(),
+						&ramstage);
+
+	if (prog_locate(&ramstage))
+		goto fail;
+
+	timestamp_add_now(TS_START_COPYRAM);
+
+	if (IS_ENABLED(CONFIG_RELOCATABLE_RAMSTAGE)) {
+		if (load_relocatable_ramstage(&ramstage))
+			goto fail;
+	} else if (cbfs_prog_stage_load(&ramstage))
+		goto fail;
+
+	stage_cache_add(STAGE_RAMSTAGE, &ramstage);
+
+	timestamp_add_now(TS_END_COPYRAM);
+
+	prog_run(&ramstage);
+
+fail:
+	die("Ramstage was not loaded!\n");
+}
+
+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)
+{
+	struct prog *payload = &global_payload;
+
+	timestamp_add_now(TS_LOAD_PAYLOAD);
+
+	if (prog_locate(payload))
+		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);
+}