/*
* 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 analized.
* 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 actuall 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;
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;
}
