misc.c

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/*
 * misc.c
 * 
 * This is a collection of several routines from gzip-1.0.3 
 * adapted for Linux.
 *
 * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
 *
 * Modified for ARM Linux by Russell King
 *
 * Nicolas Pitre <[email protected]>  1999/04/14 :
 *  For this code to run directly from Flash, all constant variables must
 *  be marked with 'const' and all other variables initialized at run-time 
 *  only.  This way all non constant variables will end up in the bss segment,
 *  which should point to addresses in RAM and cleared to 0 on start.
 *  This allows for a much quicker boot time.
 */

unsigned int __machine_arch_type;

#include <linux/compiler.h> /* for inline */
#include <linux/types.h>
#include <linux/linkage.h>

static void putstr(const char *ptr);
extern void error(char *x);

#ifdef CONFIG_ARCH_MULTIPLATFORM
static inline void putc(int c) {}
static inline void flush(void) {}
static inline void arch_decomp_setup(void) {}
#else
#include <mach/uncompress.h>
#endif

#ifdef CONFIG_DEBUG_ICEDCC

#if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) || defined(CONFIG_CPU_V7)

static void icedcc_putc(int ch)
{
    int status, i = 0x4000000;

    do {
        if (--i < 0)
            return;

        asm volatile ("mrc p14, 0, %0, c0, c1, 0" : "=r" (status));
    } while (status & (1 << 29));

    asm("mcr p14, 0, %0, c0, c5, 0" : : "r" (ch));
}


#elif defined(CONFIG_CPU_XSCALE)

static void icedcc_putc(int ch)
{
    int status, i = 0x4000000;

    do {
        if (--i < 0)
            return;

        asm volatile ("mrc p14, 0, %0, c14, c0, 0" : "=r" (status));
    } while (status & (1 << 28));

    asm("mcr p14, 0, %0, c8, c0, 0" : : "r" (ch));
}

#else

static void icedcc_putc(int ch)
{
    int status, i = 0x4000000;

    do {
        if (--i < 0)
            return;

        asm volatile ("mrc p14, 0, %0, c0, c0, 0" : "=r" (status));
    } while (status & 2);

    asm("mcr p14, 0, %0, c1, c0, 0" : : "r" (ch));
}

#endif

#define putc(ch)    icedcc_putc(ch)
#endif

static void putstr(const char *ptr)
{
    char c;

    while ((c = *ptr++) != '\0') {
        if (c == '\n')
            putc('\r');
        putc(c);
    }

    flush();
}

/*
 * gzip declarations
 */
extern char input_data[];
extern char input_data_end[];

unsigned char *output_data;

unsigned long free_mem_ptr;
unsigned long free_mem_end_ptr;

#ifndef arch_error
#define arch_error(x)
#endif

void error(char *x)
{
    arch_error(x);

    putstr("\n\n");
    putstr(x);
    putstr("\n\n -- System halted");

    while(1);   /* Halt */
}

asmlinkage void __div0(void)
{
    error("Attempting division by 0!");
}

extern int do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x));


void
decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
        unsigned long free_mem_ptr_end_p,
        int arch_id)
{
    int ret;

    output_data     = (unsigned char *)output_start;
    free_mem_ptr        = free_mem_ptr_p;
    free_mem_end_ptr    = free_mem_ptr_end_p;
    __machine_arch_type = arch_id;

    arch_decomp_setup();

    putstr("Uncompressing Linux...");
    ret = do_decompress(input_data, input_data_end - input_data,
                output_data, error);
    if (ret)
        error("decompressor returned an error");
    else
        putstr(" done, booting the kernel.\n");
}