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>

1 files changed, 6 insertions, 3 deletions

diff --git a/src/device/pci_rom.c b/src/device/pci_rom.c
index fe67515936..bb0d76066e 100644
--- a/src/device/pci_rom.c
+++ b/src/device/pci_rom.c
@@ -35,7 +35,8 @@ struct rom_header *pci_rom_probe(struct device *dev)
 	struct pci_data *rom_data;
 
 	/* If it's in FLASH, then don't check device for ROM. */
-	rom_header = cbfs_load_optionrom(dev->vendor, dev->device, NULL);
+	rom_header = cbfs_load_optionrom(CBFS_DEFAULT_MEDIA, dev->vendor,
+					 dev->device, NULL);
 
 	u32 vendev = (dev->vendor << 16) | dev->device;
 	u32 mapped_vendev = vendev;
@@ -45,8 +46,10 @@ struct rom_header *pci_rom_probe(struct device *dev)
 
 	if (!rom_header) {
 		if (vendev != mapped_vendev) {
-			rom_header = cbfs_load_optionrom(mapped_vendev >> 16,
-					mapped_vendev & 0xffff , NULL);
+			rom_header = cbfs_load_optionrom(
+					CBFS_DEFAULT_MEDIA,
+					mapped_vendev >> 16,
+					mapped_vendev & 0xffff, NULL);
 		}
 	}