![H. Peter Anvin](/assets/img/avatar_default.png)
Determine the compressed code offset (from the kernel runtime address) at compile time. This allows some minor optimizations in arch/x86/boot/compressed/head_*.S, but more importantly it makes this value available to the build process, which will enable a future patch to export the necessary linear memory footprint into the bzImage header. [ Impact: cleanup, future patch enabling ] Signed-off-by: H. Peter Anvin <hpa@zytor.com>
98 lines
2.7 KiB
C
98 lines
2.7 KiB
C
/* ----------------------------------------------------------------------- *
|
|
*
|
|
* Copyright (C) 2009 Intel Corporation. All rights reserved.
|
|
*
|
|
* 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.
|
|
*
|
|
* 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.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
* 02110-1301, USA.
|
|
*
|
|
* H. Peter Anvin <hpa@linux.intel.com>
|
|
*
|
|
* ----------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* Compute the desired load offset from a compressed program; outputs
|
|
* a small assembly wrapper with the appropriate symbols defined.
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <inttypes.h>
|
|
|
|
static uint32_t getle32(const void *p)
|
|
{
|
|
const uint8_t *cp = p;
|
|
|
|
return (uint32_t)cp[0] + ((uint32_t)cp[1] << 8) +
|
|
((uint32_t)cp[2] << 16) + ((uint32_t)cp[3] << 24);
|
|
}
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
uint32_t olen;
|
|
long ilen;
|
|
unsigned long offs;
|
|
FILE *f;
|
|
|
|
if (argc < 2) {
|
|
fprintf(stderr, "Usage: %s compressed_file\n", argv[0]);
|
|
return 1;
|
|
}
|
|
|
|
/* Get the information for the compressed kernel image first */
|
|
|
|
f = fopen(argv[1], "r");
|
|
if (!f) {
|
|
perror(argv[1]);
|
|
return 1;
|
|
}
|
|
|
|
|
|
if (fseek(f, -4L, SEEK_END)) {
|
|
perror(argv[1]);
|
|
}
|
|
fread(&olen, sizeof olen, 1, f);
|
|
ilen = ftell(f);
|
|
olen = getle32(&olen);
|
|
fclose(f);
|
|
|
|
/*
|
|
* Now we have the input (compressed) and output (uncompressed)
|
|
* sizes, compute the necessary decompression offset...
|
|
*/
|
|
|
|
offs = (olen > ilen) ? olen - ilen : 0;
|
|
offs += olen >> 12; /* Add 8 bytes for each 32K block */
|
|
offs += 32*1024 + 18; /* Add 32K + 18 bytes slack */
|
|
offs = (offs+4095) & ~4095; /* Round to a 4K boundary */
|
|
|
|
printf(".section \".rodata.compressed\",\"a\",@progbits\n");
|
|
printf(".globl z_input_len\n");
|
|
printf("z_input_len = %lu\n", ilen);
|
|
printf(".globl z_output_len\n");
|
|
printf("z_output_len = %lu\n", (unsigned long)olen);
|
|
printf(".globl z_extract_offset\n");
|
|
printf("z_extract_offset = 0x%lx\n", offs);
|
|
/* z_extract_offset_negative allows simplification of head_32.S */
|
|
printf(".globl z_extract_offset_negative\n");
|
|
printf("z_extract_offset_negative = -0x%lx\n", offs);
|
|
|
|
printf(".globl input_data, input_data_end\n");
|
|
printf("input_data:\n");
|
|
printf(".incbin \"%s\"\n", argv[1]);
|
|
printf("input_data_end:\n");
|
|
|
|
return 0;
|
|
}
|