Extend CBFS to support arbitrary ROM source media.

Summary:
	Isolate CBFS underlying I/O to board/arch-specific implementations as
	"media stream", to allow loading and booting romstage on non-x86.

	CBFS functions now all take a new "media source" parameter; use
	CBFS_DEFAULT_MEDIA if you simply want to load from main firmware.
	API Changes:
		cbfs_find => cbfs_get_file.
		cbfs_find_file => cbfs_get_file_content.
		cbfs_get_file => cbfs_get_file_content with correct type.

CBFS used to work only on memory-mapped ROM (all x86). For platforms like ARM,
the ROM may come from USB, UART, or SPI -- any serial devices and not available
for memory mapping.

To support these devices (and allowing CBFS to read from multiple source
at the same time), CBFS operations are now virtual-ized into "cbfs_media".  To
simplify porting existing code, every media source must support both "reading
into pre-allocated memory (read)" and "read and return an allocated buffer
(map)". For devices without native memory-mapped ROM, "cbfs_simple_buffer*"
provides simple memory mapping simulation.

Every CBFS function now takes a cbfs_media* as parameter. CBFS_DEFAULT_MEDIA
is defined for CBFS functions to automatically initialize a per-board default
media (CBFS will internally calls init_default_cbfs_media).  Also revised CBFS
function names relying on memory mapped backend (ex, "cbfs_find" => actually
loads files). Now we only have two getters:
	struct cbfs_file *entry = cbfs_get_file(media, name);
	void *data = cbfs_get_file_content(CBFS_DEFAULT_MEDIA, name, type);

Test results:
 - Verified to work on x86/qemu.
 - Compiles on ARM, and follow up commit will provide working SPI driver.

Change-Id: Iac911ded25a6f2feffbf3101a81364625bb07746
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: http://review.coreboot.org/2182
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

3 files changed, 105 insertions, 1 deletions

diff --git a/src/arch/x86/lib/Makefile.inc b/src/arch/x86/lib/Makefile.inc
index 2186072ab4..f4dc8b8426 100644
--- a/src/arch/x86/lib/Makefile.inc
+++ b/src/arch/x86/lib/Makefile.inc
@@ -8,13 +8,16 @@ ramstage-$(CONFIG_IOAPIC) += ioapic.c
 ramstage-y += memset.c
 ramstage-y += memcpy.c
 ramstage-y += ebda.c
+ramstage-y += rom_media.c
 
 romstage-y += romstage_console.c
 romstage-y += cbfs_and_run.c
 romstage-y += memset.c
 romstage-y += memcpy.c
+romstage-y += rom_media.c
 
 smm-y += memset.c
 smm-y += memcpy.c
+smm-y += rom_media.c
 
 $(obj)/arch/x86/lib/console.ramstage.o :: $(obj)/build.h
diff --git a/src/arch/x86/lib/cbfs_and_run.c b/src/arch/x86/lib/cbfs_and_run.c
index 1f87e7ab62..a023141650 100644
--- a/src/arch/x86/lib/cbfs_and_run.c
+++ b/src/arch/x86/lib/cbfs_and_run.c
@@ -28,7 +28,7 @@ static void cbfs_and_run_core(const char *filename, unsigned ebp)
 
 	timestamp_add_now(TS_START_COPYRAM);
 	print_debug("Loading image.\n");
-	dst = cbfs_load_stage(filename);
+	dst = cbfs_load_stage(CBFS_DEFAULT_MEDIA, filename);
 	if ((void *)dst == (void *) -1)
 		die("FATAL: Essential component is missing.\n");
 
diff --git a/src/arch/x86/lib/rom_media.c b/src/arch/x86/lib/rom_media.c
new file mode 100644
index 0000000000..ed2122cb4e
--- /dev/null
+++ b/src/arch/x86/lib/rom_media.c
@@ -0,0 +1,101 @@
+/*
+ * 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., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+#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;
+	// Some address (ex, pointer to master header) may be given in memory
+	// mapped location. To workaround that, we handle >0xf0000000 as real
+	// memory pointer.
+
+	if ((uint32_t)offset > (uint32_t)0xf0000000)
+		ptr = (void*)offset;
+	else
+		ptr = (void*)(0 - (uint32_t)media->context + offset);
+	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 = x86_rom_map(media, offset, count);
+	memcpy(dest, ptr, count);
+	x86_rom_unmap(media, ptr);
+	return count;
+}
+
+static int x86_rom_close(struct cbfs_media *media) {
+	return 0;
+}
+
+int init_x86rom_cbfs_media(struct cbfs_media *media);
+int init_x86rom_cbfs_media(struct cbfs_media *media) {
+	// On X86, we always keep a reference of pointer to CBFS header in
+	// 0xfffffffc, and the pointer is still a memory-mapped address.
+	// Since the CBFS core always use ROM offset, we need to figure out
+	// header->romsize even before media is initialized.
+	struct cbfs_header *header = (struct cbfs_header*)
+			*(uint32_t*)(0xfffffffc);
+	if (CBFS_HEADER_MAGIC != ntohl(header->magic)) {
+#if defined(CONFIG_ROM_SIZE)
+		printk(BIOS_ERR, "Invalid CBFS master header at %p\n", header);
+		media->context = (void*)CONFIG_ROM_SIZE;
+#else
+		return -1;
+#endif
+	} else {
+		uint32_t romsize = ntohl(header->romsize);
+		media->context = (void*)romsize;
+#if defined(CONFIG_ROM_SIZE)
+		if (CONFIG_ROM_SIZE != romsize)
+			printk(BIOS_INFO, "Warning: rom size unmatch (%d/%d)\n",
+			       CONFIG_ROM_SIZE, romsize);
+#endif
+	}
+	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);
+}