decompress.c

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/*
 * Copyright 2001 MontaVista Software Inc.
 * Author: Matt Porter <[email protected]>
 *
 * Copyright (C) 2009 Lemote, Inc.
 * Author: Wu Zhangjin <[email protected]>
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/types.h>
#include <linux/kernel.h>

#include <asm/addrspace.h>

/*
 * These two variables specify the free mem region
 * that can be used for temporary malloc area
 */
unsigned long free_mem_ptr;
unsigned long free_mem_end_ptr;

/* The linker tells us where the image is. */
extern unsigned char __image_begin, __image_end;

/* debug interfaces  */
extern void puts(const char *s);
extern void puthex(unsigned long long val);

void error(char *x)
{
    puts("\n\n");
    puts(x);
    puts("\n\n -- System halted");

    while (1)
        ;   /* Halt */
}

/* activate the code for pre-boot environment */
#define STATIC static

#ifdef CONFIG_KERNEL_GZIP
void *memcpy(void *dest, const void *src, size_t n)
{
    int i;
    const char *s = src;
    char *d = dest;

    for (i = 0; i < n; i++)
        d[i] = s[i];
    return dest;
}
#include "../../../../lib/decompress_inflate.c"
#endif

#ifdef CONFIG_KERNEL_BZIP2
void *memset(void *s, int c, size_t n)
{
    int i;
    char *ss = s;

    for (i = 0; i < n; i++)
        ss[i] = c;
    return s;
}
#include "../../../../lib/decompress_bunzip2.c"
#endif

#ifdef CONFIG_KERNEL_LZMA
#include "../../../../lib/decompress_unlzma.c"
#endif

#ifdef CONFIG_KERNEL_LZO
#include "../../../../lib/decompress_unlzo.c"
#endif

void decompress_kernel(unsigned long boot_heap_start)
{
    unsigned long zimage_start, zimage_size;

    zimage_start = (unsigned long)(&__image_begin);
    zimage_size = (unsigned long)(&__image_end) -
        (unsigned long)(&__image_begin);

    puts("zimage at:     ");
    puthex(zimage_start);
    puts(" ");
    puthex(zimage_size + zimage_start);
    puts("\n");

    /* This area are prepared for mallocing when decompressing */
    free_mem_ptr = boot_heap_start;
    free_mem_end_ptr = boot_heap_start + BOOT_HEAP_SIZE;

    /* Display standard Linux/MIPS boot prompt */
    puts("Uncompressing Linux at load address ");
    puthex(VMLINUX_LOAD_ADDRESS_ULL);
    puts("\n");

    /* Decompress the kernel with according algorithm */
    decompress((char *)zimage_start, zimage_size, 0, 0,
           (void *)VMLINUX_LOAD_ADDRESS_ULL, 0, error);

    /* FIXME: should we flush cache here? */
    puts("Now, booting the kernel...\n");
}