422 lines
11 KiB
C
422 lines
11 KiB
C
/*
|
|
* 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
|
|
*/
|
|
|
|
#include "misc.h"
|
|
#include "../string.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 STATIC static
|
|
|
|
#undef memcpy
|
|
|
|
/*
|
|
* Use a normal definition of memset() from string.c. There are already
|
|
* included header files which expect a definition of memset() and by
|
|
* the time we define memset macro, it is too late.
|
|
*/
|
|
#undef memset
|
|
#define memzero(s, n) memset((s), 0, (n))
|
|
|
|
|
|
static void error(char *m);
|
|
|
|
/*
|
|
* This is set up by the setup-routine at boot-time
|
|
*/
|
|
struct boot_params *real_mode; /* Pointer to real-mode data */
|
|
|
|
memptr free_mem_ptr;
|
|
memptr free_mem_end_ptr;
|
|
|
|
static char *vidmem;
|
|
static int vidport;
|
|
static int lines, cols;
|
|
|
|
#ifdef CONFIG_KERNEL_GZIP
|
|
#include "../../../../lib/decompress_inflate.c"
|
|
#endif
|
|
|
|
#ifdef CONFIG_KERNEL_BZIP2
|
|
#include "../../../../lib/decompress_bunzip2.c"
|
|
#endif
|
|
|
|
#ifdef CONFIG_KERNEL_LZMA
|
|
#include "../../../../lib/decompress_unlzma.c"
|
|
#endif
|
|
|
|
#ifdef CONFIG_KERNEL_XZ
|
|
#include "../../../../lib/decompress_unxz.c"
|
|
#endif
|
|
|
|
#ifdef CONFIG_KERNEL_LZO
|
|
#include "../../../../lib/decompress_unlzo.c"
|
|
#endif
|
|
|
|
#ifdef CONFIG_KERNEL_LZ4
|
|
#include "../../../../lib/decompress_unlz4.c"
|
|
#endif
|
|
|
|
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] = ' ';
|
|
}
|
|
|
|
#define XMTRDY 0x20
|
|
|
|
#define TXR 0 /* Transmit register (WRITE) */
|
|
#define LSR 5 /* Line Status */
|
|
static void serial_putchar(int ch)
|
|
{
|
|
unsigned timeout = 0xffff;
|
|
|
|
while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
|
|
cpu_relax();
|
|
|
|
outb(ch, early_serial_base + TXR);
|
|
}
|
|
|
|
void __putstr(const char *s)
|
|
{
|
|
int x, y, pos;
|
|
char c;
|
|
|
|
if (early_serial_base) {
|
|
const char *str = s;
|
|
while (*str) {
|
|
if (*str == '\n')
|
|
serial_putchar('\r');
|
|
serial_putchar(*str++);
|
|
}
|
|
}
|
|
|
|
if (real_mode->screen_info.orig_video_mode == 0 &&
|
|
lines == 0 && cols == 0)
|
|
return;
|
|
|
|
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 error(char *x)
|
|
{
|
|
error_putstr("\n\n");
|
|
error_putstr(x);
|
|
error_putstr("\n\n -- System halted");
|
|
|
|
while (1)
|
|
asm("hlt");
|
|
}
|
|
|
|
#if CONFIG_X86_NEED_RELOCS
|
|
static void handle_relocations(void *output, unsigned long output_len)
|
|
{
|
|
int *reloc;
|
|
unsigned long delta, map, ptr;
|
|
unsigned long min_addr = (unsigned long)output;
|
|
unsigned long max_addr = min_addr + output_len;
|
|
|
|
/*
|
|
* Calculate the delta between where vmlinux was linked to load
|
|
* and where it was actually loaded.
|
|
*/
|
|
delta = min_addr - LOAD_PHYSICAL_ADDR;
|
|
if (!delta) {
|
|
debug_putstr("No relocation needed... ");
|
|
return;
|
|
}
|
|
debug_putstr("Performing relocations... ");
|
|
|
|
/*
|
|
* The kernel contains a table of relocation addresses. Those
|
|
* addresses have the final load address of the kernel in virtual
|
|
* memory. We are currently working in the self map. So we need to
|
|
* create an adjustment for kernel memory addresses to the self map.
|
|
* This will involve subtracting out the base address of the kernel.
|
|
*/
|
|
map = delta - __START_KERNEL_map;
|
|
|
|
/*
|
|
* Process relocations: 32 bit relocations first then 64 bit after.
|
|
* Two sets of binary relocations are added to the end of the kernel
|
|
* before compression. Each relocation table entry is the kernel
|
|
* address of the location which needs to be updated stored as a
|
|
* 32-bit value which is sign extended to 64 bits.
|
|
*
|
|
* Format is:
|
|
*
|
|
* kernel bits...
|
|
* 0 - zero terminator for 64 bit relocations
|
|
* 64 bit relocation repeated
|
|
* 0 - zero terminator for 32 bit relocations
|
|
* 32 bit relocation repeated
|
|
*
|
|
* So we work backwards from the end of the decompressed image.
|
|
*/
|
|
for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) {
|
|
int extended = *reloc;
|
|
extended += map;
|
|
|
|
ptr = (unsigned long)extended;
|
|
if (ptr < min_addr || ptr > max_addr)
|
|
error("32-bit relocation outside of kernel!\n");
|
|
|
|
*(uint32_t *)ptr += delta;
|
|
}
|
|
#ifdef CONFIG_X86_64
|
|
for (reloc--; *reloc; reloc--) {
|
|
long extended = *reloc;
|
|
extended += map;
|
|
|
|
ptr = (unsigned long)extended;
|
|
if (ptr < min_addr || ptr > max_addr)
|
|
error("64-bit relocation outside of kernel!\n");
|
|
|
|
*(uint64_t *)ptr += delta;
|
|
}
|
|
#endif
|
|
}
|
|
#else
|
|
static inline void handle_relocations(void *output, unsigned long output_len)
|
|
{ }
|
|
#endif
|
|
|
|
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;
|
|
}
|
|
|
|
debug_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;
|
|
}
|
|
}
|
|
|
|
free(phdrs);
|
|
}
|
|
|
|
asmlinkage __visible void *decompress_kernel(void *rmode, memptr heap,
|
|
unsigned char *input_data,
|
|
unsigned long input_len,
|
|
unsigned char *output,
|
|
unsigned long output_len,
|
|
unsigned long run_size)
|
|
{
|
|
unsigned char *output_orig = output;
|
|
|
|
real_mode = rmode;
|
|
|
|
sanitize_boot_params(real_mode);
|
|
|
|
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;
|
|
|
|
console_init();
|
|
debug_putstr("early console in decompress_kernel\n");
|
|
|
|
free_mem_ptr = heap; /* Heap */
|
|
free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
|
|
|
|
/*
|
|
* The memory hole needed for the kernel is the larger of either
|
|
* the entire decompressed kernel plus relocation table, or the
|
|
* entire decompressed kernel plus .bss and .brk sections.
|
|
*/
|
|
output = choose_kernel_location(input_data, input_len, output,
|
|
output_len > run_size ? output_len
|
|
: run_size);
|
|
|
|
/* Validate memory location choices. */
|
|
if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
|
|
error("Destination address inappropriately aligned");
|
|
#ifdef CONFIG_X86_64
|
|
if (heap > 0x3fffffffffffUL)
|
|
error("Destination address too large");
|
|
#else
|
|
if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff))
|
|
error("Destination address too large");
|
|
#endif
|
|
#ifndef CONFIG_RELOCATABLE
|
|
if ((unsigned long)output != LOAD_PHYSICAL_ADDR)
|
|
error("Wrong destination address");
|
|
#endif
|
|
|
|
debug_putstr("\nDecompressing Linux... ");
|
|
decompress(input_data, input_len, NULL, NULL, output, NULL, error);
|
|
parse_elf(output);
|
|
/*
|
|
* 32-bit always performs relocations. 64-bit relocations are only
|
|
* needed if kASLR has chosen a different load address.
|
|
*/
|
|
if (!IS_ENABLED(CONFIG_X86_64) || output != output_orig)
|
|
handle_relocations(output, output_len);
|
|
debug_putstr("done.\nBooting the kernel.\n");
|
|
return output;
|
|
}
|