mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
synced 2024-12-27 16:58:09 +01:00
112 lines
2.7 KiB
C
112 lines
2.7 KiB
C
/*
|
|
* GRUB -- GRand Unified Bootloader
|
|
* Copyright (C) 2013 Free Software Foundation, Inc.
|
|
*
|
|
* GRUB 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, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <grub/file.h>
|
|
#include <grub/dl.h>
|
|
|
|
GRUB_MOD_LICENSE ("GPLv3+");
|
|
|
|
struct grub_offset_file
|
|
{
|
|
grub_file_t parent;
|
|
grub_off_t off;
|
|
};
|
|
|
|
static grub_ssize_t
|
|
grub_offset_read (grub_file_t file, char *buf, grub_size_t len)
|
|
{
|
|
struct grub_offset_file *data = file->data;
|
|
if (grub_file_seek (data->parent, data->off + file->offset) == (grub_off_t) -1)
|
|
return -1;
|
|
return grub_file_read (data->parent, buf, len);
|
|
}
|
|
|
|
static grub_err_t
|
|
grub_offset_close (grub_file_t file)
|
|
{
|
|
struct grub_offset_file *data = file->data;
|
|
|
|
if (data->parent)
|
|
grub_file_close (data->parent);
|
|
|
|
/* No need to close the same device twice. */
|
|
file->device = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct grub_fs grub_offset_fs = {
|
|
.name = "offset",
|
|
.dir = 0,
|
|
.open = 0,
|
|
.read = grub_offset_read,
|
|
.close = grub_offset_close,
|
|
.label = 0,
|
|
.next = 0
|
|
};
|
|
|
|
void
|
|
grub_file_offset_close (grub_file_t file)
|
|
{
|
|
struct grub_offset_file *off_data = file->data;
|
|
off_data->parent = NULL;
|
|
grub_file_close (file);
|
|
}
|
|
|
|
grub_file_t
|
|
grub_file_offset_open (grub_file_t parent, grub_off_t start, grub_off_t size)
|
|
{
|
|
struct grub_offset_file *off_data;
|
|
grub_file_t off_file, last_off_file;
|
|
grub_file_filter_id_t filter;
|
|
|
|
off_file = grub_zalloc (sizeof (*off_file));
|
|
off_data = grub_zalloc (sizeof (*off_data));
|
|
if (!off_file || !off_data)
|
|
{
|
|
grub_free (off_file);
|
|
grub_free (off_data);
|
|
return 0;
|
|
}
|
|
|
|
off_data->off = start;
|
|
off_data->parent = parent;
|
|
|
|
off_file->device = parent->device;
|
|
off_file->data = off_data;
|
|
off_file->fs = &grub_offset_fs;
|
|
off_file->size = size;
|
|
|
|
last_off_file = NULL;
|
|
for (filter = GRUB_FILE_FILTER_COMPRESSION_FIRST;
|
|
off_file && filter <= GRUB_FILE_FILTER_COMPRESSION_LAST; filter++)
|
|
if (grub_file_filters_enabled[filter])
|
|
{
|
|
last_off_file = off_file;
|
|
off_file = grub_file_filters_enabled[filter] (off_file, parent->name);
|
|
}
|
|
|
|
if (!off_file)
|
|
{
|
|
off_data->parent = NULL;
|
|
grub_file_close (last_off_file);
|
|
return 0;
|
|
}
|
|
return off_file;
|
|
}
|