* High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
*/
-#include "miscsetup.h"
+#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>
+/* 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
*/
typedef unsigned short ush;
typedef unsigned long ulg;
-#define WSIZE 0x8000 /* Window size must be at least 32k, */
- /* and a power of two */
+#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[WSIZE]; /* Sliding window buffer */
+static uch *inbuf; /* input buffer */
+static uch *window; /* Sliding window buffer, (and final output buffer) */
-static unsigned insize = 0; /* valid bytes in inbuf */
-static unsigned inptr = 0; /* index of next byte to be processed in inbuf */
-static unsigned outcnt = 0; /* bytes in 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 */
*/
static unsigned char *real_mode; /* Pointer to real-mode data */
-#define EXT_MEM_K (*(unsigned short *)(real_mode + 0x2))
+#define RM_EXT_MEM_K (*(unsigned short *)(real_mode + 0x2))
#ifndef STANDARD_MEMORY_BIOS_CALL
-#define ALT_MEM_K (*(unsigned long *)(real_mode + 0x1e0))
+#define RM_ALT_MEM_K (*(unsigned long *)(real_mode + 0x1e0))
#endif
-#define SCREEN_INFO (*(struct screen_info *)(real_mode+0))
+#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 uch *output_data;
-static unsigned long output_ptr = 0;
static void *malloc(int size);
static void free(void *where);
-
-void* memset(void* s, int c, unsigned n);
-void* memcpy(void* dest, const void* src, unsigned n);
+
+static void *memset(void *s, int c, unsigned n);
+static void *memcpy(void *dest, const void *src, unsigned n);
static void putstr(const char *);
-extern int end;
-static long free_mem_ptr = (long)&end;
+static long free_mem_ptr;
static long free_mem_end_ptr;
-#define INPLACE_MOVE_ROUTINE 0x1000
-#define LOW_BUFFER_START 0x2000
-#define LOW_BUFFER_MAX 0x90000
-#define HEAP_SIZE 0x3000
-static unsigned int low_buffer_end, low_buffer_size;
-static int high_loaded =0;
-static uch *high_buffer_start /* = (uch *)(((ulg)&end) + HEAP_SIZE)*/;
+#define HEAP_SIZE 0x7000
static char *vidmem = (char *)0xb8000;
static int vidport;
int x,y,pos;
char c;
- x = SCREEN_INFO.orig_x;
- y = SCREEN_INFO.orig_y;
+ x = RM_SCREEN_INFO.orig_x;
+ y = RM_SCREEN_INFO.orig_y;
while ( ( c = *s++ ) != '\0' ) {
if ( c == '\n' ) {
}
}
- SCREEN_INFO.orig_x = x;
- SCREEN_INFO.orig_y = 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 >> 1), vidport+1);
}
-void* memset(void* s, int c, unsigned n)
+static void* memset(void* s, int c, unsigned n)
{
int i;
char *ss = (char*)s;
return s;
}
-void* memcpy(void* dest, const void* src, unsigned n)
+static void* memcpy(void* dest, const void* src, unsigned n)
{
int i;
char *d = (char *)dest, *s = (char *)src;
*/
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];
+ 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_low(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 flush_window_high(void)
-{
- ulg c = crc; /* temporary variable */
- unsigned n;
- uch *in, ch;
- in = window;
- for (n = 0; n < outcnt; n++) {
- ch = *output_data++ = *in++;
- if ((ulg)output_data == low_buffer_end) output_data=high_buffer_start;
- c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
- }
- crc = c;
- bytes_out += (ulg)outcnt;
- outcnt = 0;
-}
-
static void flush_window(void)
{
- if (high_loaded) flush_window_high();
- else flush_window_low();
+ /* 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(x);
putstr("\n\n -- System halted");
- while(1);
-}
-
-void setup_normal_output_buffer(void)
-{
-#ifdef STANDARD_MEMORY_BIOS_CALL
- if (EXT_MEM_K < 1024) error("Less than 2MB of memory");
-#else
- if ((ALT_MEM_K > EXT_MEM_K ? ALT_MEM_K : EXT_MEM_K) < 1024) error("Less than 2MB of memory");
-#endif
- output_data = (unsigned char *)__PHYSICAL_START; /* Normally Points to 1M */
- free_mem_end_ptr = (long)real_mode;
-}
-
-struct moveparams {
- uch *low_buffer_start; int lcount;
- uch *high_buffer_start; int hcount;
-};
-
-void setup_output_buffer_if_we_run_high(struct moveparams *mv)
-{
- high_buffer_start = (uch *)(((ulg)&end) + HEAP_SIZE);
-#ifdef STANDARD_MEMORY_BIOS_CALL
- if (EXT_MEM_K < (3*1024)) error("Less than 4MB of memory");
-#else
- if ((ALT_MEM_K > EXT_MEM_K ? ALT_MEM_K : EXT_MEM_K) < (3*1024)) error("Less than 4MB of memory");
-#endif
- mv->low_buffer_start = output_data = (unsigned char *)LOW_BUFFER_START;
- low_buffer_end = ((unsigned int)real_mode > LOW_BUFFER_MAX
- ? LOW_BUFFER_MAX : (unsigned int)real_mode) & ~0xfff;
- low_buffer_size = low_buffer_end - LOW_BUFFER_START;
- high_loaded = 1;
- free_mem_end_ptr = (long)high_buffer_start;
- if ( (__PHYSICAL_START + low_buffer_size) > ((ulg)high_buffer_start)) {
- high_buffer_start = (uch *)(__PHYSICAL_START + low_buffer_size);
- mv->hcount = 0; /* say: we need not to move high_buffer */
- }
- else mv->hcount = -1;
- mv->high_buffer_start = high_buffer_start;
+ while(1); /* Halt */
}
-void close_output_buffer_if_we_run_high(struct moveparams *mv)
-{
- if (bytes_out > low_buffer_size) {
- mv->lcount = low_buffer_size;
- if (mv->hcount)
- mv->hcount = bytes_out - low_buffer_size;
- } else {
- mv->lcount = bytes_out;
- mv->hcount = 0;
- }
-}
-
-int decompress_kernel(struct moveparams *mv, void *rmode)
+asmlinkage void decompress_kernel(void *rmode, unsigned long heap,
+ uch *input_data, unsigned long input_len, uch *output)
{
real_mode = rmode;
- if (SCREEN_INFO.orig_video_mode == 7) {
+ if (RM_SCREEN_INFO.orig_video_mode == 7) {
vidmem = (char *) 0xb0000;
vidport = 0x3b4;
} else {
vidport = 0x3d4;
}
- lines = SCREEN_INFO.orig_video_lines;
- cols = SCREEN_INFO.orig_video_cols;
+ 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 (free_mem_ptr < 0x100000) setup_normal_output_buffer();
- else setup_output_buffer_if_we_run_high(mv);
+ 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");
- if (high_loaded) close_output_buffer_if_we_run_high(mv);
- return high_loaded;
+ return;
}
projects / linux-drm-fsl-dcu.git / blobdiff