forked from luck/tmp_suning_uos_patched
63 lines
2.0 KiB
C
63 lines
2.0 KiB
C
|
/*
|
||
|
|
* XIP kernel .data segment decompressor
|
||
|
|
*
|
||
|
|
* Created by: Nicolas Pitre, August 2017
|
||
|
|
* Copyright: (C) 2017 Linaro Limited
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU General Public License version 2 as
|
||
|
|
* published by the Free Software Foundation.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/init.h>
|
||
|
|
#include <linux/zutil.h>
|
||
|
|
|
||
|
|
/* for struct inflate_state */
|
||
|
|
#include "../../../lib/zlib_inflate/inftrees.h"
|
||
|
|
#include "../../../lib/zlib_inflate/inflate.h"
|
||
|
|
#include "../../../lib/zlib_inflate/infutil.h"
|
||
|
|
|
||
|
|
extern char __data_loc[];
|
||
|
|
extern char _edata_loc[];
|
||
|
|
extern char _sdata[];
|
||
|
|
|
||
|
|
/*
|
||
|
|
* This code is called very early during the boot process to decompress
|
||
|
|
* the .data segment stored compressed in ROM. Therefore none of the global
|
||
|
|
* variables are valid yet, hence no kernel services such as memory
|
||
|
|
* allocation is available. Everything must be allocated on the stack and
|
||
|
|
* we must avoid any global data access. We use a temporary stack located
|
||
|
|
* in the .bss area. The linker script makes sure the .bss is big enough
|
||
|
|
* to hold our stack frame plus some room for called functions.
|
||
|
|
*
|
||
|
|
* We mimic the code in lib/decompress_inflate.c to use the smallest work
|
||
|
|
* area possible. And because everything is statically allocated on the
|
||
|
|
* stack then there is no need to clean up before returning.
|
||
|
|
*/
|
||
|
|
|
||
|
|
int __init __inflate_kernel_data(void)
|
||
|
|
{
|
||
|
|
struct z_stream_s stream, *strm = &stream;
|
||
|
|
struct inflate_state state;
|
||
|
|
char *in = __data_loc;
|
||
|
|
int rc;
|
||
|
|
|
||
|
|
/* Check and skip gzip header (assume no filename) */
|
||
|
|
if (in[0] != 0x1f || in[1] != 0x8b || in[2] != 0x08 || in[3] & ~3)
|
||
|
|
return -1;
|
||
|
|
in += 10;
|
||
|
|
|
||
|
|
strm->workspace = &state;
|
||
|
|
strm->next_in = in;
|
||
|
|
strm->avail_in = _edata_loc - __data_loc; /* upper bound */
|
||
|
|
strm->next_out = _sdata;
|
||
|
|
strm->avail_out = _edata_loc - __data_loc;
|
||
|
|
zlib_inflateInit2(strm, -MAX_WBITS);
|
||
|
|
WS(strm)->inflate_state.wsize = 0;
|
||
|
|
WS(strm)->inflate_state.window = NULL;
|
||
|
|
rc = zlib_inflate(strm, Z_FINISH);
|
||
|
|
if (rc == Z_OK || rc == Z_STREAM_END)
|
||
|
|
rc = strm->avail_out; /* should be 0 */
|
||
|
|
return rc;
|
||
|
|
}
|