source: ar5315_microredboot/microredboot/boot/src/misc_lzma.c @ 12336

/*
 * misc_lzma.c
 * originally written for xscale based linux kernel decompression
 * now adapted for AR531X based redboot stub and kernel loader
 * copyright 2009 Sebastian Gottschall / NewMedia-NET GmbH / DD-WRT.COM
 * licensed under GPL conditions
 * this stub will load and decompress redboot if the reset button is pushed, otherwise it parses the redboot directory for a partition named linux*, vmlinux* or kernel*
 * if such a partition has been found, it will be decompressed and executed, if not. redboot is started. if a decompression error occures while loading the linux partition, 
 * the redboot is started too.
 * take care about the ramconfig.h header since it must contain the correct ram size and gpio button value for the reset button
 * this code is partially based on redboot and linux sources
 */

#ifdef STANDALONE_DEBUG
#define putstr printf
#else

#include <linux/kernel.h>

#include <asm/uaccess.h>
#include "ramconfig.h"
#include "uncompress.h"
#include "lib/lib.c"
#include "lib/print.c"
#include "lib/printf.c"

#endif

#define __ptr_t void *

typedef unsigned char uch;
typedef unsigned short ush;
typedef unsigned long ulg;

static uch *inbuf;              /* input buffer */
static unsigned int nvramdetect = 0;

static unsigned insize = 0;     /* valid bytes in inbuf */
static unsigned inptr = 0;      /* index of next byte to be processed in inbuf */
static unsigned outcnt;         /* bytes in output buffer */

static void fill_inbuf(void);

static inline unsigned char get_byte(void)
{
        static unsigned int vall;

        if (((unsigned int)inptr % 4) == 0) {
                vall = *(unsigned int *)inbuf;
                inbuf += 4;
        }
        return *(((unsigned char *)&vall) + (inptr++ & 3));
}

//#define get_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf())

static void flush_window(void);
static void error(char *m);

extern unsigned char input_data[];
extern unsigned char input_data_end[];

static ulg output_ptr = 0;
static uch *output_data;
static ulg bytes_out;

extern int end;
static ulg free_mem_ptr;
static ulg free_mem_ptr_end;

#define _LZMA_IN_CB

#include "lib/LzmaDecode.h"
static unsigned int icnt = 0;
static inline int read_byte(unsigned char **buffer, UInt32 * bufferSize)
{
        static unsigned char val;
        *bufferSize = 1;
        val = get_byte();
        *buffer = &val;
        if (icnt++ % (1024 * 10) == 0)
                putc('.');
        return LZMA_RESULT_OK;
}

#include "lib/LzmaDecode.c"

int bootoffset = 0x800004bc;

/*
 * Do the lzma decompression
 */

static int disaster = 0;
static int lzma_unzip(void)
{

        unsigned int i;
        unsigned int uncompressedSize = 0;
        unsigned char *workspace;
        unsigned int lc, lp, pb;
        if (inptr >= insize)
                fill_inbuf();

        // lzma args
        i = get_byte();
        lc = i % 9, i = i / 9;
        lp = i % 5, pb = i / 5;

        // skip dictionary size
        for (i = 0; i < 4; i++)
                get_byte();
        // get uncompressed size
        int a, b, c, d;
        a = get_byte();
        b = get_byte();
        c = get_byte();
        d = get_byte();
        uncompressedSize = (a) + (b << 8) + (c << 16) + (d << 24);
        if (uncompressedSize > 0x400000 || lc > 3 || pb > 3 || lp > 3) {
                if (disaster) {
                        error
                            ("\ndata corrupted in recovery RedBoot too, this is a disaster condition. please re-jtag\n");
                }
                disaster = 1;
                puts("\ndata corrupted!\nswitching to recovery RedBoot\nloading");
                inbuf = input_data;
                insize = &input_data_end[0] - &input_data[0];
                inptr = 0;
                output_data = (uch *) 0x80000400;
                bootoffset = 0x800004bc;
                return lzma_unzip();

        }
        workspace = output_data + uncompressedSize;
        // skip high order bytes
        for (i = 0; i < 4; i++)
                get_byte();
        // decompress kernel
        if (LzmaDecode
            (workspace, ~0, lc, lp, pb, (unsigned char *)output_data,
             uncompressedSize, &i) == LZMA_RESULT_OK) {
                if (i != uncompressedSize) {
                        if (disaster) {
                                error
                                    ("data corrupted in recovery RedBoot too, this is a disaster condition. please re-jtag\n");
                        }
                        disaster = 1;
                        puts("\ndata corrupted!\nswitching to recovery RedBoot\nloading");
                        inbuf = input_data;
                        insize = &input_data_end[0] - &input_data[0];
                        inptr = 0;
                        output_data = (uch *) 0x80000400;
                        bootoffset = 0x800004bc;
                        return lzma_unzip();
                }
                //copy it back to low_buffer
                bytes_out = i;
                output_ptr = i;
                return 0;
        }
        return 1;
}

#ifdef AR5312
#include "arch/ar5312.c"
#else
#include "arch/ar2315.c"
#endif

#include "lib/fis.c"
/* ===========================================================================
 * Fill the input buffer. This is called only when the buffer is empty
 * and at least one byte is really needed.
 */
static int resettrigger = 0;

static void fill_inbuf(void)
{
        if (insize != 0)
                error("ran out of input data");
        if (resettrigger) {
                inbuf = (uch *) linuxaddr;
                insize = 0x400000;
                inptr = 0;
        } else {
                inbuf = input_data;
                insize = &input_data_end[0] - &input_data[0];
                inptr = 0;
        }
        return;
}

/* ===========================================================================
 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 * (Used for the decompressed data only.)
 */

#ifndef arch_error
#define arch_error(x)
#endif

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

        printf("\n\n%s\n\n -- System halted", x);

        while (1) ;             /* Halt */
}

/*
 * checks if the reset button is pressed, return 1 if the button is pressed and 0 if not
 */
static int resetTouched(void)
{
        int trigger = getGPIO(RESETBUTTON & 0x0f);
        if (RESETBUTTON & 0xf0)
                trigger = 1 - trigger;
        return trigger;
}

#include <lib/nvram.c>

ulg
decompress_kernel(ulg output_start, ulg free_mem_ptr_p, ulg free_mem_ptr_end_p)
{
        output_data = (uch *) output_start;
        free_mem_ptr = free_mem_ptr_p;
        free_mem_ptr_end = free_mem_ptr_end_p;
        disable_watchdog();
        arch_decomp_setup();
        printf("MicroRedBoot v1.3, (c) 2009 DD-WRT.COM (%s)\n", __DATE__);
        nvram_init();
        char *ddboard = nvram_get("DD_BOARD");
        if (ddboard)
                printf("Board: %s\n", ddboard);
        char *resetbutton = nvram_get("resetbutton_enable");
        if (resetbutton && !strcmp(resetbutton, "1"))
                puts("reset button manual override detected! (nvram var resetbutton_enable=1)\n");
        if (resetTouched() || (resetbutton && !strcmp(resetbutton, "1"))) {
                puts("Reset Button triggered\nBooting Recovery RedBoot\n");

                int count = 5;
                while (count--) {
                        if (!resetTouched())    // check if reset button is unpressed again
                                break;
                        udelay(1000000);
                }
                if (count <= 0) {
                        puts("reset button 5 seconds pushed, erasing nvram\n");

                        if (!flashdetect())
                                flash_erase_nvram(flashsize, sectorsize);
                }

                bootoffset = 0x800004bc;
                resettrigger = 0;
        } else {
                flashdetect();
                linuxaddr = getLinux();
                puts("Booting Linux\n");
                resettrigger = 1;
                /* initialize clock */
                HAL_CLOCK_INITIALIZE(RTC_PERIOD);

                /* important, enable ethernet bus, if the following lines are not initialized linux will not be able to use the ethernet mac, taken from redboot source */
                enable_ethernet();
        }
        puts("loading");
        lzma_unzip();
        puts("\n\n\n");

        return output_ptr;
}