+++ /dev/null
-/*
- * 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
- */
-
-/*
- * we have to be careful, because no indirections are allowed here, and
- * paravirt_ops is a kind of one. As it will only run in baremetal anyway,
- * we just keep it from happening
- */
-#undef CONFIG_PARAVIRT
-#define _LINUX_STRING_H_ 1
-#define __LINUX_BITMAP_H 1
-
-#include <linux/linkage.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 long free_mem_ptr;
-static long free_mem_end_ptr;
-
-#define HEAP_SIZE 0x7000
-
-static char *vidmem = (char *)0xb8000;
-static int vidport;
-static int lines, cols;
-
-#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 = (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;
-
- 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(14, vidport);
- outb(0xff & (pos >> 9), vidport+1);
- outb(15, vidport);
- outb(0xff & (pos >> 1), vidport+1);
-}
-
-static void* memset(void* s, int c, unsigned n)
-{
- int i;
- char *ss = s;
-
- for (i=0;i<n;i++) ss[i] = c;
- return s;
-}
-
-static void* memcpy(void* dest, const void* src, unsigned n)
-{
- int i;
- const char *s = src;
- char *d = dest;
-
- 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)
- asm("hlt");
-}
-
-asmlinkage void decompress_kernel(void *rmode, unsigned long heap,
- 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 = heap; /* Heap */
- free_mem_end_ptr = heap + HEAP_SIZE;
- inbuf = input_data; /* Input buffer */
- insize = input_len;
- inptr = 0;
-
- if ((ulg)output & (__KERNEL_ALIGN - 1))
- error("Destination address not 2M aligned");
- if ((ulg)output >= 0xffffffffffUL)
- error("Destination address too large");
-
- makecrc();
- putstr("\nDecompressing Linux... ");
- gunzip();
- putstr("done.\nBooting the kernel.\n");
- return;
-}
projects / linux-2.6 / commitdiff