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>

3 files changed, 44 insertions, 100 deletions

diff --git a/src/arch/x86/lib/Makefile.inc b/src/arch/x86/lib/Makefile.inc
index e308be91bc..0d88a6daea 100644
--- a/src/arch/x86/lib/Makefile.inc
+++ b/src/arch/x86/lib/Makefile.inc
@@ -5,7 +5,6 @@ romstage-y += cbfs_and_run.c
 romstage-y += memset.c
 romstage-y += memcpy.c
 romstage-y += memmove.c
-romstage-y += rom_media.c
 romstage-y += mmap_boot.c
 
 endif # CONFIG_ARCH_ROMSTAGE_X86_32
@@ -22,7 +21,6 @@ ramstage-y += memset.c
 ramstage-y += memcpy.c
 ramstage-y += memmove.c
 ramstage-y += ebda.c
-ramstage-y += rom_media.c
 ramstage-y += mmap_boot.c
 ramstage-$(CONFIG_COOP_MULTITASKING) += thread.c
 ramstage-$(CONFIG_COOP_MULTITASKING) += thread_switch.S
@@ -33,7 +31,6 @@ romstage-$(CONFIG_COLLECT_TIMESTAMPS) += timestamp.c
 smm-y += memset.c
 smm-y += memcpy.c
 smm-y += memmove.c
-smm-y += rom_media.c
 smm-y += mmap_boot.c
 
 rmodules_x86_32-y += memset.c
diff --git a/src/arch/x86/lib/mmap_boot.c b/src/arch/x86/lib/mmap_boot.c
index eb7b23e2b1..4dd269b772 100644
--- a/src/arch/x86/lib/mmap_boot.c
+++ b/src/arch/x86/lib/mmap_boot.c
@@ -18,6 +18,10 @@
  */
 
 #include <boot_device.h>
+#include <console/console.h>
+#include <cbfs.h>
+#include <endian.h>
+#include <stdlib.h>
 
 /* The ROM is memory mapped just below 4GiB. Form a pointer for the base. */
 #define rom_base ((void *)(uintptr_t)(-(int32_t)CONFIG_ROM_SIZE))
@@ -29,3 +33,43 @@ const struct region_device *boot_device_ro(void)
 {
 	return &boot_dev.rdev;
 }
+
+int cbfs_boot_region_properties(struct cbfs_props *props)
+{
+	struct cbfs_header header;
+	int32_t offset;
+	const struct region_device *bdev;
+
+	bdev = boot_device_ro();
+
+	rdev_readat(bdev, &offset, CONFIG_ROM_SIZE - sizeof(offset),
+			sizeof(offset));
+
+	/* The offset is relative to the end of the media. */
+	offset += CONFIG_ROM_SIZE;
+
+	rdev_readat(bdev, &header , offset, sizeof(header));
+
+	header.magic = ntohl(header.magic);
+	header.romsize = ntohl(header.romsize);
+	header.bootblocksize = ntohl(header.bootblocksize);
+	header.align = ntohl(header.align);
+	header.offset = ntohl(header.offset);
+
+	if (header.magic != CBFS_HEADER_MAGIC)
+		return -1;
+
+	props->align = header.align;
+	props->offset = header.offset;
+	if (CONFIG_ROM_SIZE != header.romsize)
+		props->size = CONFIG_ROM_SIZE;
+	else
+		props->size = header.romsize;
+	props->size -= props->offset;
+	props->size -= header.bootblocksize;
+	props->size = ALIGN_DOWN(props->size, props->align);
+
+	printk(BIOS_DEBUG, "CBFS @ %zx size %zx\n", props->offset, props->size);
+
+	return 0;
+}
diff --git a/src/arch/x86/lib/rom_media.c b/src/arch/x86/lib/rom_media.c
deleted file mode 100644
index d4663c7f60..0000000000
--- a/src/arch/x86/lib/rom_media.c
+++ /dev/null
@@ -1,97 +0,0 @@
-/*
- * This file is part of the coreboot project.
- *
- * Copyright (C) 2013 The Chromium OS 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.
- */
-
-#include <boot_device.h>
-#include <cbfs.h>
-#include <string.h>
-
-#ifdef LIBPAYLOAD
-# define printk(x...)
-# define init_default_cbfs_media libpayload_init_default_cbfs_media
-  extern int libpayload_init_default_cbfs_media(struct cbfs_media *media);
-#else
-# include <console/console.h>
-#endif
-
-// Implementation of memory-mapped ROM media source on X86.
-
-static int x86_rom_open(struct cbfs_media *media) {
-	return 0;
-}
-
-static void *x86_rom_map(struct cbfs_media *media, size_t offset, size_t count) {
-	void *ptr;
-	const struct region_device *boot_dev;
-
-	boot_dev = media->context;
-
-	/* Extremely large offsets are considered relative to end of region. */
-	if ((uint32_t)offset > (uint32_t)0xf0000000)
-		offset += region_device_sz(boot_dev);
-
-	ptr = rdev_mmap(boot_dev, offset, count);
-
-	if (ptr == NULL)
-		return (void *)-1;
-
-	return ptr;
-}
-
-static void *x86_rom_unmap(struct cbfs_media *media, const void *address) {
-	return NULL;
-}
-
-static size_t x86_rom_read(struct cbfs_media *media, void *dest, size_t offset,
-			   size_t count) {
-	void *ptr;
-
-	ptr = x86_rom_map(media, offset, count);
-
-	if (ptr == (void *)-1)
-		return 0;
-
-	memcpy(dest, ptr, count);
-	x86_rom_unmap(media, ptr);
-	return count;
-}
-
-static int x86_rom_close(struct cbfs_media *media) {
-	return 0;
-}
-
-static int init_x86rom_cbfs_media(struct cbfs_media *media) {
-	boot_device_init();
-
-	media->context = (void *)boot_device_ro();
-
-	if (media->context == NULL)
-		return -1;
-
-	media->open = x86_rom_open;
-	media->close = x86_rom_close;
-	media->map = x86_rom_map;
-	media->unmap = x86_rom_unmap;
-	media->read = x86_rom_read;
-	return 0;
-}
-
-int init_default_cbfs_media(struct cbfs_media *media) {
-	return init_x86rom_cbfs_media(media);
-}