// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2009 Thomas Chou <thomas@wytron.com.tw>
 *
 * This is a collection of several routines from gzip-1.0.3
 * adapted for Linux.
 *
 * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
 *
 * Adapted for SH by Stuart Menefy, Aug 1999
 *
 * Modified to use standard LinuxSH BIOS by Greg Banks 7Jul2000
 *
 * Based on arch/sh/boot/compressed/misc.c
 */

#include <linux/string.h>

/*
 * gzip declarations
 */
#define OF(args)  args
#define STATIC static

#undef memset
#undef memcpy
#define memzero(s, n)           memset((s), 0, (n))

typedef unsigned char  uch;
typedef unsigned short ush;
typedef unsigned long  ulg;
#define WSIZE 0x8000            /* Window size must be at least 32k, */
                                /* and a power of two */

static uch *inbuf;              /* input buffer */
static uch window[WSIZE];       /* Sliding window buffer */

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

/* gzip flag byte */
#define ASCII_FLAG      0x01 /* bit 0 set: file probably ASCII text */
#define CONTINUATION    0x02 /* bit 1 set: continuation of multi-part gzip
                                file */
#define EXTRA_FIELD     0x04 /* bit 2 set: extra field present */
#define ORIG_NAME       0x08 /* bit 3 set: original file name present */
#define COMMENT         0x10 /* bit 4 set: file comment present */
#define ENCRYPTED       0x20 /* bit 5 set: file is encrypted */
#define RESERVED        0xC0 /* bit 6,7:   reserved */

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

#ifdef DEBUG
#  define Assert(cond, msg) {if (!(cond)) error(msg); }
#  define Trace(x) fprintf x
#  define Tracev(x) {if (verbose) fprintf x ; }
#  define Tracevv(x) {if (verbose > 1) fprintf x ; }
#  define Tracec(c, x) {if (verbose && (c)) fprintf x ; }
#  define Tracecv(c, x) {if (verbose > 1 && (c)) fprintf x ; }
#else
#  define Assert(cond, msg)
#  define Trace(x)
#  define Tracev(x)
#  define Tracevv(x)
#  define Tracec(c, x)
#  define Tracecv(c, x)
#endif
static int  fill_inbuf(void);
static void flush_window(void);
static void error(char *m);

extern char input_data[];
extern int input_len;

static long bytes_out;
static uch *output_data;
static unsigned long output_ptr;

#include "console.c"

static void error(char *m);

int puts(const char *);

extern int _end;
static unsigned long free_mem_ptr;
static unsigned long free_mem_end_ptr;

#define HEAP_SIZE                       0x10000

#include "../../../../lib/inflate.c"

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

        for (i = 0; i < n; i++)
                ss[i] = c;
        return s;
}

void *memcpy(void *__dest, __const void *__src, size_t __n)
{
        int i;
        char *d = (char *)__dest, *s = (char *)__src;

        for (i = 0; i < __n; i++)
                d[i] = s[i];
        return __dest;
}

/*
 * Fill the input buffer. This is called only when the buffer is empty
 * and at least one byte is really needed.
 */
static int fill_inbuf(void)
{
        if (insize != 0)
                error("ran out of input data");

        inbuf = input_data;
        insize = input_len;
        inptr = 1;
        return inbuf[0];
}

/*
 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 * (Used for the decompressed data only.)
 */
static void flush_window(void)
{
        ulg c = crc;    /* temporary variable */
        unsigned n;
        uch *in, *out, ch;

        in = window;
        out = &output_data[output_ptr];
        for (n = 0; n < outcnt; n++) {
                ch = *out++ = *in++;
                c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
        }
        crc = c;
        bytes_out += (ulg)outcnt;
        output_ptr += (ulg)outcnt;
        outcnt = 0;
}

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

        while (1)       /* Halt */
                ;
}

void decompress_kernel(void)
{
        output_data = (void *) (CONFIG_NIOS2_MEM_BASE |
                                CONFIG_NIOS2_KERNEL_REGION_BASE);
        output_ptr = 0;
        free_mem_ptr = (unsigned long)&_end;
        free_mem_end_ptr = free_mem_ptr + HEAP_SIZE;

        console_init();
        makecrc();
        puts("Uncompressing Linux... ");
        gunzip();
        puts("Ok, booting the kernel.\n");
}