text: /*
   * 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
   * puts by Nick Holloway 1993, better puts by Martin Mares 1995
   * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
   */
  
  #undef CONFIG_PARAVIRT
  #include <linux/linkage.h>
  #include <linux/vmalloc.h>
  #include <linux/screen_info.h>
  #include <asm/io.h>
  #include <asm/page.h>
  #include <asm/boot.h>
  
  /* WARNING!!
   * This code is compiled with -fPIC and it is relocated dynamically
   * at run time, but no relocation processing is performed.
   * This means that it is not safe to place pointers in static structures.
   */
  
  /*
   * Getting to provable safe in place decompression is hard.
   * Worst case behaviours need to be analyzed.
   * Background information:
   *
   * The file layout is:
   *    magic[2]
   *    method[1]
   *    flags[1]
   *    timestamp[4]
   *    extraflags[1]
   *    os[1]
   *    compressed data blocks[N]
   *    crc[4] orig_len[4]
   *
   * resulting in 18 bytes of non compressed data overhead.
   *
   * Files divided into blocks
   * 1 bit (last block flag)
   * 2 bits (block type)
   *
   * 1 block occurs every 32K -1 bytes or when there 50% compression has been achieved.
   * The smallest block type encoding is always used.
   *
   * stored:
   *    32 bits length in bytes.
   *
   * fixed:
   *    magic fixed tree.
   *    symbols.
   *
   * dynamic:
   *    dynamic tree encoding.
   *    symbols.
   *
   *
   * The buffer for decompression in place is the length of the
   * uncompressed data, plus a small amount extra to keep the algorithm safe.
   * The compressed data is placed at the end of the buffer.  The output
   * pointer is placed at the start of the buffer and the input pointer
   * is placed where the compressed data starts.  Problems will occur
   * when the output pointer overruns the input pointer.
   *
   * The output pointer can only overrun the input pointer if the input
   * pointer is moving faster than the output pointer.  A condition only
   * triggered by data whose compressed form is larger than the uncompressed
   * form.
   *
   * The worst case at the block level is a growth of the compressed data
   * of 5 bytes per 32767 bytes.
   *
   * The worst case internal to a compressed block is very hard to figure.
   * The worst case can at least be boundined by having one bit that represents
   * 32764 bytes and then all of the rest of the bytes representing the very
   * very last byte.
   *
   * All of which is enough to compute an amount of extra data that is required
   * to be safe.  To avoid problems at the block level allocating 5 extra bytes
   * per 32767 bytes of data is sufficient.  To avoind problems internal to a block
   * adding an extra 32767 bytes (the worst case uncompressed block size) is
   * sufficient, to ensure that in the worst case the decompressed data for
   * block will stop the byte before the compressed data for a block begins.
   * To avoid problems with the compressed data's meta information an extra 18
   * bytes are needed.  Leading to the formula:
   *
   * extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
   *
   * Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
   * Adding 32768 instead of 32767 just makes for round numbers.
   * Adding the decompressor_size is necessary as it musht live after all
   * of the data as well.  Last I measured the decompressor is about 14K.
   * 10K of actual data and 4K of bss.
   *
   */
  
  /*
   * 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 0x80000000	/* Window size must be at least 32k,
  				 * and a power of two
  				 * We don't actually have a window just
  				 * a huge output buffer so I report
  				 * a 2G windows size, as that should
  				 * always be larger than our output buffer.
  				 */
  
  static uch *inbuf;	/* input buffer */
  static uch *window;	/* Sliding window buffer, (and final output 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())
  		
  /* Diagnostic functions */
  #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);
  static void gzip_mark(void **);
  static void gzip_release(void **);
    
  /*
   * This is set up by the setup-routine at boot-time
   */
  static unsigned char *real_mode; /* Pointer to real-mode data */
  
  #define RM_EXT_MEM_K   (*(unsigned short *)(real_mode + 0x2))
  #ifndef STANDARD_MEMORY_BIOS_CALL
  #define RM_ALT_MEM_K   (*(unsigned long *)(real_mode + 0x1e0))
  #endif
  #define RM_SCREEN_INFO (*(struct screen_info *)(real_mode+0))
  
  extern unsigned char input_data[];
  extern int input_len;
  
  static long bytes_out = 0;
  
  static void *malloc(int size);
  static void free(void *where);
  
  static void *memset(void *s, int c, unsigned n);
  static void *memcpy(void *dest, const void *src, unsigned n);
  
  static void putstr(const char *);
  
  static unsigned long free_mem_ptr;
  static unsigned long free_mem_end_ptr;
  
  #define HEAP_SIZE             0x4000
  
  static char *vidmem = (char *)0xb8000;
  static int vidport;
  static int lines, cols;
  
  #ifdef CONFIG_X86_NUMAQ
  void *xquad_portio;
  #endif
  
  #include "../../../../lib/inflate.c"
  
  static void *malloc(int size)
  {
  	void *p;
  
  	if (size <0) error("Malloc error");
  	if (free_mem_ptr <= 0) error("Memory error");
  
  	free_mem_ptr = (free_mem_ptr + 3) & ~3;	/* Align */
  
  	p = (void *)free_mem_ptr;
  	free_mem_ptr += size;
  
  	if (free_mem_ptr >= free_mem_end_ptr)
  		error("Out of memory");
  
  	return p;
  }
  
  static void free(void *where)
  {	/* Don't care */
  }
  
  static void gzip_mark(void **ptr)
  {
  	*ptr = (void *) free_mem_ptr;
  }
  
  static void gzip_release(void **ptr)
  {
  	free_mem_ptr = (unsigned long) *ptr;
  }
   
  static void scroll(void)
  {
  	int i;
  
  	memcpy ( vidmem, vidmem + cols * 2, ( lines - 1 ) * cols * 2 );
  	for ( i = ( lines - 1 ) * cols * 2; i < lines * cols * 2; i += 2 )
  		vidmem[i] = ' ';
  }
  
  static void putstr(const char *s)
  {
  	int x,y,pos;
  	char c;
  
  	if (RM_SCREEN_INFO.orig_video_mode == 0 && lines == 0 && cols == 0)
  		return;
  
  	x = RM_SCREEN_INFO.orig_x;
  	y = RM_SCREEN_INFO.orig_y;
  
  	while ( ( c = *s++ ) != '\0' ) {
  		if ( c == '\n' ) {
  			x = 0;
  			if ( ++y >= lines ) {
  				scroll();
  				y--;
  			}
  		} else {
  			vidmem [ ( x + cols * y ) * 2 ] = c;
  			if ( ++x >= cols ) {
  				x = 0;
  				if ( ++y >= lines ) {
  					scroll();
  					y--;
  				}
  			}
  		}
  	}
  
  	RM_SCREEN_INFO.orig_x = x;
  	RM_SCREEN_INFO.orig_y = y;
  
  	pos = (x + cols * y) * 2;	/* Update cursor position */
  	outb_p(14, vidport);
  	outb_p(0xff & (pos >> 9), vidport+1);
  	outb_p(15, vidport);
  	outb_p(0xff & (pos >> 1), vidport+1);
  }
  
  static void* memset(void* s, int c, unsigned n)
  {
  	int i;
  	char *ss = (char*)s;
  
  	for (i=0;i<n;i++) ss[i] = c;
  	return s;
  }
  
  static void* memcpy(void* dest, const void* src, unsigned 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)
  {
  	error("ran out of input data");
  	return 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)
  {
  	/* With my window equal to my output buffer
  	 * I only need to compute the crc here.
  	 */
  	ulg c = crc;         /* temporary variable */
  	unsigned n;
  	uch *in, ch;
  
  	in = window;
  	for (n = 0; n < outcnt; n++) {
  		ch = *in++;
  		c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
  	}
  	crc = c;
  	bytes_out += (ulg)outcnt;
  	outcnt = 0;
  }
  
  static void error(char *x)
  {
  	putstr("\n\n");
  	putstr(x);
  	putstr("\n\n -- System halted");
  
  	while(1);	/* Halt */
  }
  
  asmlinkage void decompress_kernel(void *rmode, unsigned long end,
  			uch *input_data, unsigned long input_len, uch *output)
  {
  	real_mode = rmode;
  
  	if (RM_SCREEN_INFO.orig_video_mode == 7) {
  		vidmem = (char *) 0xb0000;
  		vidport = 0x3b4;
  	} else {
  		vidmem = (char *) 0xb8000;
  		vidport = 0x3d4;
  	}
  
  	lines = RM_SCREEN_INFO.orig_video_lines;
  	cols = RM_SCREEN_INFO.orig_video_cols;
  
  	window = output;  	/* Output buffer (Normally at 1M) */
  	free_mem_ptr     = end;	/* Heap  */
  	free_mem_end_ptr = end + HEAP_SIZE;
  	inbuf  = input_data;	/* Input buffer */
  	insize = input_len;
  	inptr  = 0;
  
  	if ((u32)output & (CONFIG_PHYSICAL_ALIGN -1))
  		error("Destination address not CONFIG_PHYSICAL_ALIGN aligned");
  	if (end > ((-__PAGE_OFFSET-(512 <<20)-1) & 0x7fffffff))
  		error("Destination address too large");
  #ifndef CONFIG_RELOCATABLE
  	if ((u32)output != LOAD_PHYSICAL_ADDR)
  		error("Wrong destination address");
  #endif
  
  	makecrc();
  	putstr("Uncompressing Linux... ");
  	gunzip();
  	putstr("Ok, booting the kernel.\n");
  	return;
  }
  