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02a884c0fe
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
/* ----------------------------------------------------------------------- *
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*
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* Copyright (C) 2009 Intel Corporation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version
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* 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*
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* H. Peter Anvin <hpa@linux.intel.com>
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*
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* ----------------------------------------------------------------------- */
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/*
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* Compute the desired load offset from a compressed program; outputs
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* a small assembly wrapper with the appropriate symbols defined.
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <inttypes.h>
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static uint32_t getle32(const void *p)
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{
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const uint8_t *cp = p;
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return (uint32_t)cp[0] + ((uint32_t)cp[1] << 8) +
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((uint32_t)cp[2] << 16) + ((uint32_t)cp[3] << 24);
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}
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int main(int argc, char *argv[])
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{
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uint32_t olen;
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long ilen;
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unsigned long offs;
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FILE *f;
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if (argc < 2) {
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fprintf(stderr, "Usage: %s compressed_file\n", argv[0]);
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return 1;
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}
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/* Get the information for the compressed kernel image first */
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f = fopen(argv[1], "r");
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if (!f) {
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perror(argv[1]);
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return 1;
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}
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if (fseek(f, -4L, SEEK_END)) {
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perror(argv[1]);
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}
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fread(&olen, sizeof olen, 1, f);
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ilen = ftell(f);
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olen = getle32(&olen);
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fclose(f);
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/*
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* Now we have the input (compressed) and output (uncompressed)
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* sizes, compute the necessary decompression offset...
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*/
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offs = (olen > ilen) ? olen - ilen : 0;
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offs += olen >> 12; /* Add 8 bytes for each 32K block */
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offs += 32*1024 + 18; /* Add 32K + 18 bytes slack */
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offs = (offs+4095) & ~4095; /* Round to a 4K boundary */
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printf(".section \".rodata.compressed\",\"a\",@progbits\n");
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printf(".globl z_input_len\n");
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printf("z_input_len = %lu\n", ilen);
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printf(".globl z_output_len\n");
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printf("z_output_len = %lu\n", (unsigned long)olen);
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printf(".globl z_extract_offset\n");
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printf("z_extract_offset = 0x%lx\n", offs);
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/* z_extract_offset_negative allows simplification of head_32.S */
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printf(".globl z_extract_offset_negative\n");
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printf("z_extract_offset_negative = -0x%lx\n", offs);
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printf(".globl input_data, input_data_end\n");
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printf("input_data:\n");
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printf(".incbin \"%s\"\n", argv[1]);
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printf("input_data_end:\n");
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return 0;
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}
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