1. 根目录:
2. arch
3. mips
4. boot
5. compressed
6. decompress.c

/*
 * Copyright 2001 MontaVista Software Inc.
 * Author: Matt Porter <mporter@mvista.com>
 *
 * Copyright (C) 2009 Lemote, Inc.
 * Author: Wu Zhangjin <wuzhangjin@gmail.com>
 *
 * 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");
}