coreboot-kgpe-d16/src/lib/cbfs_spi.c

81 lines
2.1 KiB
C

/*
* This file is part of the coreboot project.
*
* Copyright 2014 Google Inc.
*
* 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.
*/
/*
* This file provides a common CBFS wrapper for SPI storage. SPI driver
* context is expanded with the buffer descriptor used to store data read from
* SPI.
*/
#include <boot_device.h>
#include <spi_flash.h>
#include <symbols.h>
#include <cbmem.h>
static struct spi_flash *spi_flash_info;
static ssize_t spi_readat(const struct region_device *rd, void *b,
size_t offset, size_t size)
{
if (spi_flash_info->read(spi_flash_info, offset, size, b))
return -1;
return size;
}
static const struct region_device_ops spi_ops = {
.mmap = mmap_helper_rdev_mmap,
.munmap = mmap_helper_rdev_munmap,
.readat = spi_readat,
};
static struct mmap_helper_region_device mdev =
MMAP_HELPER_REGION_INIT(&spi_ops, 0, CONFIG_ROM_SIZE);
static void switch_to_postram_cache(int unused)
{
/*
* Call boot_device_init() to ensure spi_flash is initialized before
* backing mdev with postram cache. This prevents the mdev backing from
* being overwritten if spi_flash was not accessed before dram was up.
*/
boot_device_init();
if (_preram_cbfs_cache != _postram_cbfs_cache)
mmap_helper_device_init(&mdev, _postram_cbfs_cache,
_postram_cbfs_cache_size);
}
ROMSTAGE_CBMEM_INIT_HOOK(switch_to_postram_cache);
void boot_device_init(void)
{
int bus = CONFIG_BOOT_MEDIA_SPI_BUS;
int cs = 0;
if (spi_flash_info != NULL)
return;
spi_flash_info = spi_flash_probe(bus, cs);
mmap_helper_device_init(&mdev, _cbfs_cache, _cbfs_cache_size);
}
/* Return the CBFS boot device. */
const struct region_device *boot_device_ro(void)
{
if (spi_flash_info == NULL)
return NULL;
return &mdev.rdev;
}