/*
* 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
*/
#include "gzip.h"
#include "lzw.h"
#define EOF -1
DECLARE(uch, inbuf, INBUFSIZ);
DECLARE(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
DECLARE(uch, window, WSIZE);
unsigned outcnt;
unsigned insize;
unsigned inptr;
extern char input_data[];
extern int input_len;
int input_ptr;
int method, exit_code, part_nb, last_member;
int test = 0;
int force = 0;
int verbose = 1;
long bytes_in, bytes_out;
char *output_data;
unsigned long output_ptr;
extern int end;
long free_mem_ptr = (long)&end;
int to_stdout = 0;
int hard_math = 0;
void (*work)(int inf, int outf);
void makecrc(void);
local int get_method(int);
char *vidmem = (char *)0xC00B8000;
int lines, cols;
int orig_x, orig_y;
void puts(const char *);
void *malloc(int size)
{
void *p;
if (size <0) error("Malloc error\n");
if (free_mem_ptr <= 0) error("Memory error\n");
while(1) {
free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
p = (void *)free_mem_ptr;
free_mem_ptr += size;
/*
* The part of the compressed kernel which has already been expanded
* is no longer needed. Therefore we can reuse it for malloc.
* With bigger kernels, this is necessary.
*/
if (free_mem_ptr < (long)&end) {
if (free_mem_ptr > (long)&input_data[input_ptr])
error("\nOut of memory\n");
return p;
}
#if 0
if (free_mem_ptr < 0x90000)
#endif
return p;
puts("large kernel, low 1M tight...");
free_mem_ptr = (long)input_data;
}
}
void free(void *where)
{ /* Don't care */
}
static void scroll()
{
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] = ' ';
}
void puts(const char *s)
{
int x,y;
char c;
#if 0
x = SCREEN_INFO.orig_x;
y = SCREEN_INFO.orig_y;
#else
x = orig_x;
y = orig_y;
#endif
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--;
}
}
}
}
#if 0
SCREEN_INFO.orig_x = x;
SCREEN_INFO.orig_y = y;
#else
orig_x = x;
orig_y = y;
#endif
}
__ptr_t memset(__ptr_t s, int c, size_t n)
{
int i;
char *ss = (char*)s;
for (i=0;i<n;i++) ss[i] = c;
}
__ptr_t memcpy(__ptr_t __dest, __const __ptr_t __src,
size_t __n)
{
int i;
char *d = (char *)__dest, *s = (char *)__src;
for (i=0;i<__n;i++) d[i] = s[i];
}
int memcmp(__ptr_t __dest, __const __ptr_t __src,
size_t __n)
{
int i;
char *d = (char *)__dest, *s = (char *)__src;
for (i=0;i<__n;i++, d++, s++)
{
if (*d != *s)
{
return (*s - *d);
}
}
return (0);
}
extern ulg crc_32_tab[]; /* crc table, defined below */
/* ===========================================================================
* Run a set of bytes through the crc shift register. If s is a NULL
* pointer, then initialize the crc shift register contents instead.
* Return the current crc in either case.
*/
ulg updcrc(s, n)
uch *s; /* pointer to bytes to pump through */
unsigned n; /* number of bytes in s[] */
{
register ulg c; /* temporary variable */
static ulg crc = (ulg)0xffffffffL; /* shift register contents */
if (s == NULL) {
c = 0xffffffffL;
} else {
c = crc;
while (n--) {
c = crc_32_tab[((int)c ^ (*s++)) & 0xff] ^ (c >> 8);
}
}
crc = c;
return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
}
/* ===========================================================================
* Clear input and output buffers
*/
void clear_bufs()
{
outcnt = 0;
insize = inptr = 0;
bytes_in = bytes_out = 0L;
}
/* ===========================================================================
* Fill the input buffer. This is called only when the buffer is empty
* and at least one byte is really needed.
*/
int fill_inbuf()
{
int len, i;
/* Read as much as possible */
puts("*");
insize = 0;
do {
len = INBUFSIZ-insize;
if (len > (input_len-input_ptr+1)) len=input_len-input_ptr+1;
if (len == 0 || len == EOF) break;
for (i=0;i<len;i++) inbuf[insize+i] = input_data[input_ptr+i];
insize += len;
input_ptr += len;
} while (insize < INBUFSIZ);
if (insize == 0) {
error("unable to fill buffer\n");
}
bytes_in += (ulg)insize;
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.)
*/
void flush_window()
{
if (outcnt == 0) return;
updcrc(window, outcnt);
memcpy(&output_data[output_ptr], (char *)window, outcnt);
bytes_out += (ulg)outcnt;
output_ptr += (ulg)outcnt;
outcnt = 0;
}
/*
* Code to compute the CRC-32 table. Borrowed from
* gzip-1.0.3/makecrc.c.
*/
ulg crc_32_tab[256];
void
makecrc(void)
{
/* Not copyrighted 1990 Mark Adler */
unsigned long c; /* crc shift register */
unsigned long e; /* polynomial exclusive-or pattern */
int i; /* counter for all possible eight bit values */
int k; /* byte being shifted into crc apparatus */
/* terms of polynomial defining this crc (except x^32): */
static int p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26};
/* Make exclusive-or pattern from polynomial */
e = 0;
for (i = 0; i < sizeof(p)/sizeof(int); i++)
e |= 1L << (31 - p[i]);
crc_32_tab[0] = 0;
for (i = 1; i < 256; i++)
{
c = 0;
for (k = i | 256; k != 1; k >>= 1)
{
c = c & 1 ? (c >> 1) ^ e : c >> 1;
if (k & 1)
c ^= e;
}
crc_32_tab[i] = c;
}
}
void error(char *x)
{
puts("\n\n");
puts(x);
puts("\n\n -- System halted");
while(1); /* Halt */
}
#if 0
#define STACK_SIZE (4096)
long user_stack [STACK_SIZE];
struct {
long * a;
short b;
} stack_start = { & user_stack [STACK_SIZE] , KERNEL_DS };
#endif
void decompress_kernel()
{
#if 0
if (SCREEN_INFO.orig_video_mode == 7)
vidmem = (char *) 0xb0000;
else
vidmem = (char *) 0xb8000;
lines = SCREEN_INFO.orig_video_lines;
cols = SCREEN_INFO.orig_video_cols;
if (EXT_MEM_K < 1024) error("<2M of mem\n");
output_data = (char *)0x100000; /* Points to 1M */
#else
output_data = (char *)0x0; /* Points to 0 */
lines = 25;
cols = 80;
orig_x = 0;
orig_y = 24;
#endif
output_ptr = 0;
exit_code = 0;
test = 0;
input_ptr = 0;
part_nb = 0;
clear_bufs();
makecrc();
puts("Uncompressing Linux...");
method = get_method(0);
work(0, 0);
puts("done.\n");
puts("Now booting the kernel\n");
}
/* ========================================================================
* Check the magic number of the input file and update ofname if an
* original name was given and to_stdout is not set.
* Return the compression method, -1 for error, -2 for warning.
* Set inptr to the offset of the next byte to be processed.
* This function may be called repeatedly for an input file consisting
* of several contiguous gzip'ed members.
* IN assertions: there is at least one remaining compressed member.
* If the member is a zip file, it must be the only one.
*/
local int get_method(in)
int in; /* input file descriptor */
{
uch flags;
char magic[2]; /* magic header */
magic[0] = (char)get_byte();
magic[1] = (char)get_byte();
method = -1; /* unknown yet */
part_nb++; /* number of parts in gzip file */
last_member = 0;
/* assume multiple members in gzip file except for record oriented I/O */
if (memcmp(magic, GZIP_MAGIC, 2) == 0
|| memcmp(magic, OLD_GZIP_MAGIC, 2) == 0) {
work = unzip;
method = (int)get_byte();
flags = (uch)get_byte();
if ((flags & ENCRYPTED) != 0)
error("Input is encrypted\n");
if ((flags & CONTINUATION) != 0)
error("Multi part input\n");
if ((flags & RESERVED) != 0) {
error("Input has invalid flags\n");
exit_code = ERROR;
if (force <= 1) return -1;
}
(ulg)get_byte(); /* Get timestamp */
((ulg)get_byte()) << 8;
((ulg)get_byte()) << 16;
((ulg)get_byte()) << 24;
(void)get_byte(); /* Ignore extra flags for the moment */
(void)get_byte(); /* Ignore OS type for the moment */
if ((flags & EXTRA_FIELD) != 0) {
unsigned len = (unsigned)get_byte();
len |= ((unsigned)get_byte())<<8;
while (len--) (void)get_byte();
}
/* Get original file name if it was truncated */
if ((flags & ORIG_NAME) != 0) {
if (to_stdout || part_nb > 1) {
/* Discard the old name */
while (get_byte() != 0) /* null */ ;
} else {
} /* to_stdout */
} /* orig_name */
/* Discard file comment if any */
if ((flags & COMMENT) != 0) {
while (get_byte() != 0) /* null */ ;
}
} else
error("unknown compression method");
return method;
}
