mkpiggy.c

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/* ----------------------------------------------------------------------- *
 *
 *  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 <[email protected]>
 *
 * ----------------------------------------------------------------------- */

/*
 * 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>
#include <tools/le_byteshift.h>

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]);
    }

    if (fread(&olen, sizeof(olen), 1, f) != 1) {
        perror(argv[1]);
        return 1;
    }

    ilen = ftell(f);
    olen = get_unaligned_le32(&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 += 64*1024 + 128;  /* Add 64K + 128 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;
}