coreboot-kgpe-d16/src/arch/x86/lib/rom_media.c
Hung-Te Lin 6fe0cab205 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>
2013-01-30 17:58:32 +01:00

101 lines
3.1 KiB
C

/*
* 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);
}