coreboot-kgpe-d16/src/include/region_file.h

63 lines
2.0 KiB
C

/*
* This file is part of the coreboot project.
*
* Copyright 2016 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.
*/
#ifndef REGION_FILE_H
#define REGION_FILE_H
#include <commonlib/region.h>
#include <stdint.h>
/*
* A region file is an abstraction to allow appending updates in a
* region_device where the data returned is the most recently written
* data. It is block based with a 16 byte granularity. So if you write
* 2 bytes into the file the data returned in the region_device would
* have 16 bytes allocated for the latest update. Additionally, the
* current maximum file size allowed is 1MiB - 48 bytes. See comments
* in C implementation file for further details.
*/
struct region_file;
/*
* Initialize a region file associated with a provided region device.
* Returns < 0 on error, 0 on success.
*/
int region_file_init(struct region_file *f, const struct region_device *p);
/*
* Initialize region device object associated with latest update of file data.
* Returns < 0 on error, 0 on success.
*/
int region_file_data(const struct region_file *f, struct region_device *rdev);
/* Update region file with latest data. Returns < 0 on error, 0 on success. */
int region_file_update_data(struct region_file *f, const void *buf,
size_t size);
/* Declared here for easy object allocation. */
struct region_file {
/* Region device covering file */
struct region_device rdev;
/* Metadata containing blocks of the data stream. */
struct region_device metadata;
/* Blocks forming data. */
uint16_t data_blocks[2];
/* Current slot in metadata marking end of data. */
int slot;
};
#endif /* REGION_FILE_H */