Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * XIP kernel .data segment decompressor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * Created by:	Nicolas Pitre, August 2017
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  * Copyright:	(C) 2017  Linaro Limited
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/zutil.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) /* for struct inflate_state */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include "../../../lib/zlib_inflate/inftrees.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include "../../../lib/zlib_inflate/inflate.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include "../../../lib/zlib_inflate/infutil.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) extern char __data_loc[];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) extern char _edata_loc[];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) extern char _sdata[];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)  * This code is called very early during the boot process to decompress
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)  * the .data segment stored compressed in ROM. Therefore none of the global
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)  * variables are valid yet, hence no kernel services such as memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)  * allocation is available. Everything must be allocated on the stack and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)  * we must avoid any global data access. We use a temporary stack located
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)  * in the .bss area. The linker script makes sure the .bss is big enough
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)  * to hold our stack frame plus some room for called functions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)  * We mimic the code in lib/decompress_inflate.c to use the smallest work
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)  * area possible. And because everything is statically allocated on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)  * stack then there is no need to clean up before returning.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) int __init __inflate_kernel_data(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	struct z_stream_s stream, *strm = &stream;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	struct inflate_state state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	char *in = __data_loc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	int rc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	/* Check and skip gzip header (assume no filename) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	if (in[0] != 0x1f || in[1] != 0x8b || in[2] != 0x08 || in[3] & ~3)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 		return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 	in += 10;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	strm->workspace = &state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 	strm->next_in = in;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 	strm->avail_in = _edata_loc - __data_loc;  /* upper bound */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 	strm->next_out = _sdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	strm->avail_out = _edata_loc - __data_loc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 	zlib_inflateInit2(strm, -MAX_WBITS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 	WS(strm)->inflate_state.wsize = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 	WS(strm)->inflate_state.window = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 	rc = zlib_inflate(strm, Z_FINISH);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 	if (rc == Z_OK || rc == Z_STREAM_END)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 		rc = strm->avail_out;  /* should be 0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 	return rc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) }