|  | /* | 
|  | * 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; | 
|  | } |