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, 7 insertions, 3 deletions

diff --git a/src/northbridge/amd/agesa/family15tn/fam15tn_callouts.c b/src/northbridge/amd/agesa/family15tn/fam15tn_callouts.c
index 7c3b0ac9cf..8c5605c041 100644
--- a/src/northbridge/amd/agesa/family15tn/fam15tn_callouts.c
+++ b/src/northbridge/amd/agesa/family15tn/fam15tn_callouts.c
@@ -398,7 +398,9 @@ AGESA_STATUS fam15tn_DefaultRet (UINT32 Func, UINT32 Data, VOID *ConfigPtr)
 AGESA_STATUS fam15tn_HookGfxGetVbiosImage(UINT32 Func, UINT32 FchData, VOID *ConfigPrt)
 {
 	GFX_VBIOS_IMAGE_INFO  *pVbiosImageInfo = (GFX_VBIOS_IMAGE_INFO *)ConfigPrt;
-	pVbiosImageInfo->ImagePtr = cbfs_find_file("pci"CONFIG_VGA_BIOS_ID".rom", CBFS_TYPE_OPTIONROM);
+	pVbiosImageInfo->ImagePtr = cbfs_get_file_content(
+			CBFS_DEFAULT_MEDIA, "pci"CONFIG_VGA_BIOS_ID".rom",
+			CBFS_TYPE_OPTIONROM);
 	/* printk(BIOS_DEBUG, "IMGptr=%x\n", pVbiosImageInfo->ImagePtr); */
 	return pVbiosImageInfo->ImagePtr == NULL ? AGESA_WARNING : AGESA_SUCCESS;
 }
diff --git a/src/northbridge/intel/i82830/vga.c b/src/northbridge/intel/i82830/vga.c
index 1ec7f87b6b..40e7d9d9d2 100644
--- a/src/northbridge/intel/i82830/vga.c
+++ b/src/northbridge/intel/i82830/vga.c
@@ -32,7 +32,7 @@
 static void vga_init(device_t dev)
 {
 	printk(BIOS_INFO, "Starting Graphics Initialization\n");
-	struct cbfs_file *file = cbfs_find("mbi.bin");
+	struct cbfs_file *file = cbfs_get_file(CBFS_DEFAULT_MEDIA, "mbi.bin");
 	void *mbi = NULL;
 	unsigned int mbi_len = 0;
 
diff --git a/src/northbridge/intel/sandybridge/raminit.c b/src/northbridge/intel/sandybridge/raminit.c
index b5a1c23f94..f25aaa1195 100644
--- a/src/northbridge/intel/sandybridge/raminit.c
+++ b/src/northbridge/intel/sandybridge/raminit.c
@@ -252,7 +252,9 @@ void sdram_initialize(struct pei_data *pei_data)
 	pei_data->tx_byte = console_tx_byte;
 
 	/* Locate and call UEFI System Agent binary. */
-	entry = (unsigned long)cbfs_find_file("mrc.bin", 0xab);
+	/* TODO make MRC blob (0xab?) defined in cbfs_core.h. */
+	entry = (unsigned long)cbfs_get_file_content(
+			CBFS_DEFAULT_MEDIA, "mrc.bin", 0xab);
 	if (entry) {
 		int rv;
 		asm volatile (