ARM bootblock approach

This lays out the groundwork for using a proper bootblock on ARM.
Currently we bypass the bootblock entirely and go straight to
romstage. However we want to utilize CBFS to maximize flexibility
of placing code without relying on a lot of magic numbers which
will break depending on the SoC in use.

Change-Id: I9cc2a8191d2db38b27b6363ba673e5a360de9684
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/2118
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/arch/armv7/Makefile.inc

@@ -149,7 +149,6 @@ CFLAGS += \
 # For various headers imported from Linux
 CFLAGS += -D__LINUX_ARM_ARCH__=7
 
-crt0s = $(src)/arch/armv7/bootblock.inc
 ldscripts =
 ldscripts += $(src)/arch/armv7/romstage.ld
 
@@ -223,19 +222,14 @@ $(obj)/coreboot.pre: $(objcbfs)/romstage_xip.elf $(obj)/coreboot.pre1 $(CBFSTOOL
 ################################################################################
 # Build the bootblock
 
-#bootblock_lds = $(src)/arch/armv7/ldscript_fallback_cbfs.lb
+bootblock_lds = $(src)/arch/armv7/bootblock.lds
-bootblock_lds = $(src)/arch/armv7/lib/id.lds
+bootblock_lds += $(src)/arch/armv7/lib/id.lds
-#bootblock_lds = $(src)/arch/armv7/romstage.ld
 bootblock_lds += $(chipset_bootblock_lds)
 
+bootblock_inc += $(src)/arch/armv7/bootblock.inc
 bootblock_inc += $(src)/arch/armv7/lib/id.inc
 bootblock_inc += $(chipset_bootblock_inc)
-
+bootblock_inc += $(objgenerated)/bootblock.inc
-# FIXME: CONFIG_NEON or something similar for ARM?
-#ifeq ($(CONFIG_SSE),y)
-#bootblock_inc += $(src)/cpu/x86/sse_enable.inc
-#endif
-#bootblock_inc += $(objgenerated)/bootblock.inc
 
 $(objgenerated)/bootblock.ld: $$(bootblock_lds) $(obj)/ldoptions
 	@printf "    GEN        $(subst $(obj)/,,$(@))\n"
@@ -253,11 +247,11 @@ $(objgenerated)/bootblock.s: $(objgenerated)/bootblock_inc.S $(obj)/config.h $(o
 	@printf "    CC         $(subst $(obj)/,,$(@))\n"
 	$(CC) -MMD -x assembler-with-cpp -E -I$(src)/include -I$(src)/arch/armv7/include -I$(obj) -include $(obj)/build.h -include $(obj)/config.h -I. -I$(src) $< -o $@
 
-#$(objgenerated)/bootblock.inc: $(src)/arch/armv7/init/$(subst ",,$(CONFIG_BOOTBLOCK_SOURCE)) $(objutil)/romcc/romcc $(OPTION_TABLE_H)
+$(objgenerated)/bootblock.inc: $(src)/arch/armv7/$(subst ",,$(CONFIG_BOOTBLOCK_SOURCE)) $(OPTION_TABLE_H)
-#	@printf "    ROMCC      $(subst $(obj)/,,$(@))\n"
+	@printf "    CC      $(subst $(obj)/,,$(@))\n"
-#	$(CC) $(INCLUDES) -MM -MT$(objgenerated)/bootblock.inc \
+	$(CC) $(INCLUDES) -MM -MT$(objgenerated)/bootblock.inc \
-#		$< > $(objgenerated)/bootblock.inc.d
+		$< > $(objgenerated)/bootblock.inc.d
-#	$(ROMCC) -c -S $(bootblock_romccflags) $(ROMCCFLAGS) -I. $(INCLUDES) $< -o $@
+	$(CC) -c -S $(CFLAGS) -I. $(INCLUDES) $< -o $@
 
 $(objcbfs)/bootblock.debug: $(objgenerated)/bootblock.o $(objgenerated)/bootblock.ld
 	@printf "    LINK       $(subst $(obj)/,,$(@))\n"

src/arch/armv7/bootblock.inc

@@ -36,8 +36,7 @@ _bl1:
 	 * on ARM, which is 8KB in size and it is prepended to the
 	 * reset vector
 	 */
-	/* this comes a bit later. */
+	.skip 8192
-//	.skip 8192
 
 .globl _start
 _start: b	reset
@@ -81,10 +80,6 @@ call_bootblock:
 	 * Thumb. However, "b" will not and GCC may attempt to create a
 	 * wrapper which is currently broken.
 	 */
-	/* for now call board_init_f; change later. We're trying to get as much into ToT as
-	 * we can
-	 */
-	bl	board_init_f
 	bl	main
 
 wait_for_interrupt:

src/arch/armv7/bootblock.lds

@@ -0,0 +1,49 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2006 Advanced Micro Devices, Inc.
+ * Copyright (C) 2008-2010 coresystems GmbH
+ *
+ * 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
+ */
+
+/* We use ELF as output format. So that we can debug the code in some form. */
+OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm")
+OUTPUT_ARCH(arm)
+
+TARGET(binary)
+SECTIONS
+{
+	ROMLOC = 0x2023400 - 8192;
+
+	/* This section might be better named .setup */
+	.rom ROMLOC : {
+		_rom = .;
+		*(.text);
+		*(.text.*);
+		*(.rom.text);
+		*(.rom.data);
+		*(.rom.data.*);
+		*(.rodata.*);
+		_erom = .;
+	} = 0xff
+
+	/DISCARD/ : {
+		*(.comment)
+		*(.note)
+		*(.comment.*)
+		*(.note.*)
+		*(.ARM.*)
+	}
+}

src/arch/armv7/bootblock_simple.c

@@ -19,33 +19,31 @@
  * MA 02110-1301 USA
  */
 
-
-
 #include <bootblock_common.h>
+#include <arch/cbfs.h>
+#include <arch/hlt.h>
 
-
+static int boot_cpu(void)
-#include "../../lib/uart8250.c"
+{
-#include "lib/div.c"
+	/*
-
+	 * FIXME: This is a stub for now. All non-boot CPUs should be
-struct uart8250 uart = {
+	 * waiting for an interrupt. We could move the chunk of assembly
-	115200
+	 * which puts them to sleep in here...
-}; 
+	 */
+	return 1;
+}
 
 void main(unsigned long bist)
 {
-	init_uart8250(CONFIG_TTYS0_BASE, &uart);
-	uart8250_tx_byte(CONFIG_TTYS0_BASE, '@');
-
-	if (boot_cpu()) {
-		bootblock_cpu_init();
-		bootblock_northbridge_init();
-		bootblock_southbridge_init();
-	}
 	const char *target1 = "fallback/romstage";
 	unsigned long entry;
+
+	if (boot_cpu()) {
+		bootblock_mainboard_init();
+	}
+
 	entry = findstage(target1);
-	if (entry) call(entry, bist);
+	if (entry) call(entry);
 
 	hlt();
 }
-

src/arch/armv7/include/arch/cbfs.h

@@ -0,0 +1,67 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2012 The ChromiumOS Authors.  All rights reserved.
+ *
+ * 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
+ */
+
+#ifndef __INCLUDE_ARCH_CBFS__
+#define __INCLUDE_ARCH_CBFS__
+
+#include <string.h>
+#include <types.h>
+#include <cbfs_core.h>
+#include <arch/byteorder.h>
+#include <arch/cbfs.h>
+
+static int cbfs_check_magic(struct cbfs_file *file)
+{
+	return !strcmp(file->magic, CBFS_FILE_MAGIC) ? 1 : 0;
+}
+
+static unsigned long findstage(const char* target)
+{
+	unsigned long offset, align;
+	/* FIXME: magic offsets */
+	struct cbfs_header *header = (struct cbfs_header *)(0x02023400 + 0x40);
+	// if (ntohl(header->magic) != CBFS_HEADER_MAGIC)
+	// 	printk(BIOS_ERR, "ERROR: No valid CBFS header found!\n");
+
+	offset = ntohl(header->offset);
+	align = ntohl(header->align);
+	while(1) {
+		struct cbfs_file *file;
+		file = (struct cbfs_file *)(offset + CONFIG_ROMSTAGE_BASE);
+		if (!cbfs_check_magic(file))
+			return 0;
+		if (!strcmp(CBFS_NAME(file), target))
+			return (unsigned long)CBFS_SUBHEADER(file);
+		int flen = ntohl(file->len);
+		int foffset = ntohl(file->offset);
+		unsigned long oldoffset = offset;
+		offset = ALIGN(offset + foffset + flen, align);
+		if (offset <= oldoffset)
+			return 0;
+		if (offset < CONFIG_ROMSTAGE_BASE + ntohl(header->romsize));
+			return 0;
+	}
+}
+
+static inline void call(unsigned long addr)
+{
+	void (*doit)(void) = (void *)addr;
+	doit();
+}
+#endif

src/arch/armv7/include/bootblock_common.h

@@ -1,69 +1,14 @@
-#include <types.h>
-#include <cbfs.h>
-#include <string.h>
-#include <arch/byteorder.h>
-
-
-#define boot_cpu(x) 1
-
 #ifdef CONFIG_BOOTBLOCK_CPU_INIT
 #include CONFIG_BOOTBLOCK_CPU_INIT
-#else
-static void bootblock_cpu_init(void) { }
-#endif
-#ifdef CONFIG_BOOTBLOCK_NORTHBRIDGE_INIT
-#include CONFIG_BOOTBLOCK_NORTHBRIDGE_INIT
-#else
-static void bootblock_northbridge_init(void) { }
-#endif
-#ifdef CONFIG_BOOTBLOCK_SOUTHBRIDGE_INIT
-#include CONFIG_BOOTBLOCK_SOUTHBRIDGE_INIT
-#else
-static void bootblock_southbridge_init(void) { }
 #endif
 
-static int cbfs_check_magic(struct cbfs_file *file)
+#ifdef CONFIG_BOOTBLOCK_MAINBOARD_INIT
+#include CONFIG_BOOTBLOCK_MAINBOARD_INIT
+#else
+static void bootblock_mainboard_init(void)
 {
-	return !strcmp(file->magic, CBFS_FILE_MAGIC) ? 1 : 0;
+#ifdef CONFIG_BOOTBLOCK_CPU_INIT
-}
+	bootblock_cpu_init();
-
+#endif
-static unsigned long findstage(const char* target)
-{
-	unsigned long offset;
-
-	void *ptr = (void *)*((unsigned long *) CBFS_HEADPTR_ADDR);
-	struct cbfs_header *header = (struct cbfs_header *) ptr;
-	// if (ntohl(header->magic) != CBFS_HEADER_MAGIC)
-	// 	printk(BIOS_ERR, "ERROR: No valid CBFS header found!\n");
-
-	offset = 0 - ntohl(header->romsize) + ntohl(header->offset);
-	int align = ntohl(header->align);
-	while(1) {
-		struct cbfs_file *file = (struct cbfs_file *) offset;
-		if (!cbfs_check_magic(file))
-			return 0;
-		if (!strcmp(CBFS_NAME(file), target))
-			return (unsigned long)CBFS_SUBHEADER(file);
-		int flen = ntohl(file->len);
-		int foffset = ntohl(file->offset);
-		unsigned long oldoffset = offset;
-		offset = ALIGN(offset + foffset + flen, align);
-		if (offset <= oldoffset)
-			return 0;
-		if (offset < 0xFFFFFFFF - ntohl(header->romsize))
-			return 0;
-	}
-}
-
-
-static void call(unsigned long addr, unsigned long bist)
-{
-	asm volatile ("mov r0, %1\nbx %0\n" : : "r" (addr), "r" (bist));
-}
-
-static void hlt(void)
-{
-	/* is there such a thing as hlt on ARM? */
-	// asm volatile ("1:\n\thlt\n\tjmp 1b\n\t");
-	asm volatile ("1:\nb 1b\n\t");
 }
+#endif

src/arch/armv7/lib/id.lds

@@ -1,5 +1,6 @@
 SECTIONS {
-	. = (0x100000000 - CONFIG_ID_SECTION_OFFSET) - (__id_end - __id_start);
+	/* FIXME: determine a sensible location... */
+	. = (0x2024000) - (__id_end - __id_start);
 	.id (.): {
 		*(.id)
 	}

src/cpu/samsung/exynos5250/Kconfig

@@ -1,10 +1,3 @@
-config BOOTBLOCK_OFFSET
-	hex "Bootblock offset"
-	default 0x3400
-	help
-	  This is where the Coreboot bootblock resides. For Exynos5250,
-	  this value is pre-determined by the vendor-provided BL1.
-
 config EXYNOS_ACE_SHA
 	bool
 	default n