/*
* 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
#ifdef CONFIG_X86_32
#define _ASM_DESC_H_ 1
#endif
#ifdef CONFIG_X86_64
#define _LINUX_STRING_H_ 1
#define __LINUX_BITMAP_H 1
#endif
#include <linux/linkage.h>
#include <linux/screen_info.h>
#include <linux/elf.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/boot.h>
#include <asm/bootparam.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;
/*
* 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 we report a 2G window size, as that should always be
* larger than our output buffer:
*/
#define WSIZE 0x80000000
/* Input buffer: */
static unsigned char *inbuf;
/* Sliding window buffer (and final output buffer): */
static unsigned char *window;
/* Valid bytes in inbuf: */
static unsigned insize;
/* Index of next byte to be processed in inbuf: */
static unsigned inptr;
/* Bytes in output buffer: */
static unsigned outcnt;
/* gzip flag byte */
#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gz file */
#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
#define ORIG_NAM 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) do { if (!(cond)) error(msg); } while (0)
# define Trace(x) do { fprintf x; } while (0)
# define Tracev(x) do { if (verbose) fprintf x ; } while (0)
# define Tracevv(x) do { if (verbose > 1) fprintf x ; } while (0)
# define Tracec(c, x) do { if (verbose && (c)) fprintf x ; } while (0)
# define Tracecv(c, x) do { if (verbose > 1 && (c)) fprintf x ; } while (0)
#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);
/*
* This is set up by the setup-routine at boot-time
*/
static struct boot_params *real_mode; /* Pointer to real-mode data */
static int quiet;
extern unsigned char input_data[];
extern int input_len;
static long bytes_out;
static void *memset(void *s, int c, unsigned n);
static void *memcpy(void *dest, const void *src, unsigned n);
static void __putstr(int, const char *);
#define putstr(__x) __putstr(0, __x)
#ifdef CONFIG_X86_64
#define memptr long
#else
#define memptr unsigned
#endif
static memptr free_mem_ptr;
static memptr free_mem_end_ptr;
static char *vidmem;
static int vidport;
static int lines, cols;
#include "../../../../lib/inflate.c"
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(int error, const char *s)
{
int x, y, pos;
char c;
#ifndef CONFIG_X86_VERBOSE_BOOTUP
if (!error)
return;
#endif
#ifdef CONFIG_X86_32
if (real_mode->screen_info.orig_video_mode == 0 &&
lines == 0 && cols == 0)
return;
#endif
x = real_mode->screen_info.orig_x;
y = real_mode->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--;
}
}
}
}
real_mode->screen_info.orig_x = x;
real_mode->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.
*/
unsigned long c = crc; /* temporary variable */
unsigned n;
unsigned char *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 += (unsigned long)outcnt;
outcnt = 0;
}
static void error(char *x)
{
__putstr(1, "\n\n");
__putstr(1, x);
__putstr(1, "\n\n -- System halted");
while (1)
asm("hlt");
}
static void parse_elf(void *output)
{
#ifdef CONFIG_X86_64
Elf64_Ehdr ehdr;
Elf64_Phdr *phdrs, *phdr;
#else
Elf32_Ehdr ehdr;
Elf32_Phdr *phdrs, *phdr;
#endif
void *dest;
int i;
memcpy(&ehdr, output, sizeof(ehdr));
if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
ehdr.e_ident[EI_MAG3] != ELFMAG3) {
error("Kernel is not a valid ELF file");
return;
}
if (!quiet)
putstr("Parsing ELF... ");
phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
if (!phdrs)
error("Failed to allocate space for phdrs");
memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum);
for (i = 0; i < ehdr.e_phnum; i++) {
phdr = &phdrs[i];
switch (phdr->p_type) {
case PT_LOAD:
#ifdef CONFIG_RELOCATABLE
dest = output;
dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
#else
dest = (void *)(phdr->p_paddr);
#endif
memcpy(dest,
output + phdr->p_offset,
phdr->p_filesz);
break;
default: /* Ignore other PT_* */ break;
}
}
}
asmlinkage void decompress_kernel(void *rmode, memptr heap,
unsigned char *input_data,
unsigned long input_len,
unsigned char *output)
{
real_mode = rmode;
if (real_mode->hdr.loadflags & QUIET_FLAG)
quiet = 1;
if (real_mode->screen_info.orig_video_mode == 7) {
vidmem = (char *) 0xb0000;
vidport = 0x3b4;
} else {
vidmem = (char *) 0xb8000;
vidport = 0x3d4;
}
lines = real_mode->screen_info.orig_video_lines;
cols = real_mode->screen_info.orig_video_cols;
window = output; /* Output buffer (Normally at 1M) */
free_mem_ptr = heap; /* Heap */
free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
inbuf = input_data; /* Input buffer */
insize = input_len;
inptr = 0;
#ifdef CONFIG_X86_64
if ((unsigned long)output & (__KERNEL_ALIGN - 1))
error("Destination address not 2M aligned");
if ((unsigned long)output >= 0xffffffffffUL)
error("Destination address too large");
#else
if ((u32)output & (CONFIG_PHYSICAL_ALIGN - 1))
error("Destination address not CONFIG_PHYSICAL_ALIGN aligned");
if (heap > ((-__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
#endif
makecrc();
if (!quiet)
putstr("\nDecompressing Linux... ");
gunzip();
parse_elf(output);
if (!quiet)
putstr("done.\nBooting the kernel.\n");
return;
}
