coreboot-kgpe-d16/payloads/libpayload/libcbfs/ram_media.c

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/*
* This file is part of the libpayload project.
*
* Copyright (C) 2013 Google, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <cbfs.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
// Implementation of a media source based on given memory buffer.
struct ram_media {
char *start;
size_t size;
};
static int ram_open(struct cbfs_media *media) {
return 0;
}
static void *ram_map(struct cbfs_media *media, size_t offset, size_t count) {
struct ram_media *m = (struct ram_media*)media->context;
/* assume addressing from top of image in this case */
if (offset > 0xf0000000) {
offset = m->size + offset;
}
if (offset + count > m->size) {
printf("ERROR: ram_map: request out of range (0x%x+0x%x)\n",
offset, count);
return NULL;
}
return (void*)(m->start + offset);
}
static void *ram_unmap(struct cbfs_media *media, const void *address) {
return NULL;
}
static size_t ram_read(struct cbfs_media *media, void *dest, size_t offset,
size_t count) {
void *ptr = ram_map(media, offset, count);
memcpy(dest, ptr, count);
ram_unmap(media, ptr);
return count;
}
static int ram_close(struct cbfs_media *media) {
return 0;
}
int init_cbfs_ram_media(struct cbfs_media *media, void *start, size_t size);
int init_cbfs_ram_media(struct cbfs_media *media, void *start, size_t size) {
// TODO Find a way to release unused media. Maybe adding media->destroy.
struct ram_media *m = (struct ram_media*)malloc(sizeof(*m));
m->start = start;
m->size = size;
media->context = (void*)m;
media->open = ram_open;
media->close = ram_close;
media->map = ram_map;
media->unmap = ram_unmap;
media->read = ram_read;
return 0;
}
// Legacy setup_cbfs_from_*.
static int is_default_cbfs_media_initialized;
static struct cbfs_media default_cbfs_media;
int setup_cbfs_from_ram(void *start, uint32_t size);
int setup_cbfs_from_ram(void *start, uint32_t size) {
int result = init_cbfs_ram_media(&default_cbfs_media, start, size);
if (result == 0)
is_default_cbfs_media_initialized = 1;
return result;
}
extern int libpayload_init_default_cbfs_media(struct cbfs_media *media);
int setup_cbfs_from_flash(void);
int setup_cbfs_from_flash(void) {
int result = libpayload_init_default_cbfs_media(&default_cbfs_media);
if (result == 0)
is_default_cbfs_media_initialized = 1;
return result;
}
int init_default_cbfs_media(struct cbfs_media *media) {
int result = 0;
if (is_default_cbfs_media_initialized != 1) {
result = setup_cbfs_from_flash();
}
if (result == 0)
memcpy(media, &default_cbfs_media, sizeof(*media));
return result;
}