bootblock: Support normal/fallback mechanism again

Change-Id: I7395e62f6682f4ef123da10ac125127a57711ec6
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37760
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/arch/x86/Kconfig

@@ -232,11 +232,10 @@ config ROMSTAGE_DEBUG_SPINLOOP
 	  Add a spin (JMP .) in assembly_entry.S during early romstage to wait
 	  for a JTAG debugger to break into the execution sequence.
 
-# Selecting a cbfs prefix from the bootblock is only implemented with romcc
 choice
 	prompt "Bootblock behaviour"
 	default BOOTBLOCK_SIMPLE
-	depends on ROMCC_BOOTBLOCK
+	depends on !VBOOT
 
 config BOOTBLOCK_SIMPLE
 	bool "Always load fallback"

src/arch/x86/Makefile.inc

@@ -112,7 +112,7 @@ bootblock-$(CONFIG_IDT_IN_EVERY_STAGE) += exception.c
 bootblock-$(CONFIG_IDT_IN_EVERY_STAGE) += idt.S
 bootblock-$(CONFIG_COLLECT_TIMESTAMPS_TSC) += timestamp.c
 bootblock-$(CONFIG_X86_TOP4G_BOOTMEDIA_MAP) += mmap_boot.c
-
+bootblock-$(CONFIG_BOOTBLOCK_NORMAL) += bootblock_normal.c
 bootblock-y += id.S
 $(call src-to-obj,bootblock,$(dir)/id.S): $(obj)/build.h
 

src/arch/x86/bootblock_normal.c

@@ -0,0 +1,45 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * 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.
+ */
+
+#include <cbfs.h>
+#include <pc80/mc146818rtc.h>
+#include <program_loading.h>
+#include <stddef.h>
+#include <string.h>
+
+static const char *get_fallback(const char *stagelist)
+{
+	while (*stagelist)
+		stagelist++;
+	return ++stagelist;
+}
+
+int legacy_romstage_selector(struct prog *romstage)
+{
+	static const char *default_filenames = "normal/romstage\0fallback/romstage";
+	const char *boot_candidate;
+	size_t stages_len;
+
+	boot_candidate = cbfs_boot_map_with_leak("coreboot-stages", CBFS_TYPE_RAW, &stages_len);
+	if (!boot_candidate)
+		boot_candidate = default_filenames;
+
+	if (do_normal_boot()) {
+		romstage->name = boot_candidate;
+		if (!prog_locate(romstage))
+			return 0;
+	}
+
+	romstage->name = get_fallback(boot_candidate);
+	return prog_locate(romstage);
+}

src/include/program_loading.h

@@ -179,6 +179,9 @@ struct prog_loader_ops {
 /* Run romstage from bootblock. */
 void run_romstage(void);
 
+/* Runtime selector for CBFS_PREFIX of romstage. */
+int legacy_romstage_selector(struct prog *romstage);
+
 /************************
  *   RAMSTAGE LOADING   *
  ************************/

src/lib/prog_loaders.c

@@ -60,8 +60,13 @@ void run_romstage(void)
 
 	vboot_run_logic();
 
-	if (prog_locate(&romstage))
-		goto fail;
+	if (CONFIG(ARCH_X86) && CONFIG(BOOTBLOCK_NORMAL)) {
+		if (legacy_romstage_selector(&romstage))
+			goto fail;
+	} else {
+		if (prog_locate(&romstage))
+			goto fail;
+	}
 
 	timestamp_add_now(TS_START_COPYROM);