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elilo/x86_64/gzip.c

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/*
* Copyright (C) 2001-2002 Hewlett-Packard Co.
* Contributed by Stephane Eranian <eranian@hpl.hp.com>
*
* Copyright (C) 2001 Silicon Graphics, Inc.
* Contributed by Brent Casavant <bcasavan@sgi.com>
*
* Copyright (C) 2006-2009 Intel Corporation
* Contributed by Fenghua Yu <fenghua.yu@intel.com>
* Contributed by Bibo Mao <bibo.mao@intel.com>
* Contributed by Chandramouli Narayanan <mouli@linux.intel.com>
*
* This file is part of the ELILO, the EFI Linux boot loader.
*
* ELILO is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* ELILO is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with ELILO; see the file COPYING. If not, write to the Free
* Software Foundation, 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*
* Please check out the elilo.txt for complete documentation on how
* to use this program.
*/
#include <efi.h>
#include <efilib.h>
#include "elf.h"
#include "elilo.h"
#include "gzip.h"
#include "private.h"
#define memzero(s, n) Memset((VOID *)(s), 0, (n))
#define memcpy(a,b,n) Memcpy((VOID *)(a),(b),(n))
/* size of output buffer */
#define WSIZE 0x8000 /* Window size must be at least 32k, */
/* and a power of two */
/* size of input buffer */
#define INBUFSIZE 0x8000
/*
* gzip declarations
*/
#define OF(args) args
#define FUNC_STATIC static
typedef unsigned char uch;
typedef unsigned short ush;
typedef unsigned long ulg;
typedef struct segment {
unsigned long addr; /* start address */
unsigned long offset; /* file offset */
unsigned long size; /* file size */
unsigned long bss_sz; /* BSS size */
UINT8 flags; /* indicates whether to load or not */
} segment_t;
#define CHUNK_FL_VALID 0x1
#define CHUNK_FL_LOAD 0x2
#define CHUNK_CAN_LOAD(n) chunks[(n)].flags |= CHUNK_FL_LOAD
#define CHUNK_NO_LOAD(n) chunks[(n)].flags &= ~CHUNK_FL_LOAD
#define CHUNK_IS_LOAD(n) (chunks[(n)].flags & CHUNK_FL_LOAD)
#define CHUNK_VALIDATE(n) chunks[(n)].flags |= CHUNK_FL_VALID
#define CHUNK_INVALIDATE(n) chunks[(n)].flags = 0
#define CHUNK_IS_VALID(n) (chunks[(n)].flags & CHUNK_FL_VALID)
/*
* static parameters to gzip helper functions
* we cannot use paramters because API was not
* designed that way
*/
static segment_t *chunks; /* holds the list of segments */
static segment_t *cur_chunk;
static UINTN nchunks;
static UINTN chunk; /* current segment */
static UINTN input_fd;
static VOID *kernel_entry, *kernel_base, *kernel_end;
static uch *inbuf; /* input buffer (compressed data) */
static uch *window; /* output buffer (uncompressed data) */
static unsigned long file_offset; /* position in the file */
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 */
/* gzip flag byte */
#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
#define ORIG_NAME 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 INFLATE_DEBUG
# define Assert(cond,msg) {if(!(cond)) error(msg);}
int stderr;
# define Trace(x) Print(L"line %d:\n", __LINE__);
# define Tracev(x) {if (verbose) Print(L"line %d:\n", __LINE__) ;}
# define Tracevv(x) {if (verbose>1) Print(L"line %d:\n", __LINE__) ;}
# define Tracec(c,x) {if (verbose && (c)) Print(L"line %d:\n", __LINE__) ;}
# define Tracecv(c,x) {if (verbose>1 && (c)) Print(L"line %d:\n", __LINE__) ;}
#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);
static long bytes_out;
static void error(char *m);
static int error_return;
static void *
gzip_malloc(int size)
{
return (void *)alloc(size, 0);
}
static void
gzip_free(void *where)
{
return free(where);
}
#include "inflate.c"
/*
* Fill the input buffer and return the first byte in it. This is called
* only when the buffer is empty and at least one byte is really needed.
*/
int
fill_inbuf(void)
{
UINTN expected, nread;
EFI_STATUS status;
expected = nread = INBUFSIZE;
status = fops_read(input_fd, inbuf, &nread);
if (EFI_ERROR(status)) {
error("elilo: Read failed");
}
#ifdef DEBUG_GZIP
DBG_PRT((L"%s : read %d bytes of %d bytes\n", LD_NAME, nread, expected));
#endif
insize = nread;
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.)
*/
/*
* 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.
*
* Input:
* S pointer to bytes to pump through.
* N number of bytes in S[].
*/
unsigned long
updcrc(unsigned char *s, unsigned n)
{
register unsigned long c;
/* crc is defined in inflate.c */
if (!s) {
c = 0xffffffffL;
} else {
c = crc;
while (n--) {
c = crc_32_tab[((int)c ^ (*s++)) & 0xff] ^ (c >> 8);
}
}
crc = c;
return c ^ 0xffffffffUL; /* (instead of ~c for 64-bit machines) */
}
/*
* Clear input and output buffers
*/
void
clear_bufs(void)
{
outcnt = 0;
inptr = 0;
chunk = 0;
cur_chunk = NULL;
file_offset = 0;
}
static INTN
is_valid_header(Elf64_Ehdr *ehdr)
{
UINT16 type, machine;
type = ehdr->e_type;
machine = ehdr->e_machine;
VERB_PRT(3, Print(L"class=%d type=%d data=%d machine=%d\n",
ehdr->e_ident[EI_CLASS],
type,
ehdr->e_ident[EI_DATA],
machine));
return ehdr->e_ident[EI_MAG0] == 0x7f
&& ehdr->e_ident[EI_MAG1] == 'E'
&& ehdr->e_ident[EI_MAG2] == 'L'
&& ehdr->e_ident[EI_MAG3] == 'F'
&& ehdr->e_ident[EI_CLASS] == ELFCLASS64
&& type == ET_EXEC /* must be executable */
&& machine == EM_X86_64 ? 0 : -1;
}
/*
* will invalidate loadble segments which overlap with others
*/
void
check_overlap(int i)
{
int j;
unsigned long iend = chunks[i].addr + chunks[i].size;
for(j=0; j < nchunks; j++) {
if (j ==i) continue;
if (chunks[i].addr >= chunks[j].addr && iend < (chunks[j].addr + chunks[j].size)) {
DBG_PRT((L"%s : segment %d fully included in segment %d\n", LD_NAME, i, j));
CHUNK_INVALIDATE(i); /* nullyify segment */
break;
}
}
}
void
analyze_chunks(void)
{
INTN i;
for (i=0; i < nchunks; i++) {
if (CHUNK_IS_VALID(i) && !CHUNK_IS_LOAD(i))
check_overlap(i);
}
}
/*
* The decompression code calls this function after decompressing the
* first block of the object file. The first block must contain all
* the relevant header information.
*/
int
first_block (const unsigned char *buf, long blocksize)
{
Elf64_Ehdr *elf;
Elf64_Phdr *phdrs;
UINTN total_size, pages;
UINTN low_addr, max_addr;
UINTN offs = 0;
UINT16 phnum;
UINTN paddr, memsz;
INTN i;
elf = (Elf64_Ehdr *)buf;
if (is_valid_header(elf) == -1)
return -1;
offs = elf->e_phoff;
phnum = elf->e_phnum;
VERB_PRT(3, {
Print(L"Entry point 0x%lx\n", elf->e_entry);
Print(L"%d program headers\n", phnum);
Print(L"%d segment headers\n", elf->e_shnum);
});
if (offs + phnum * sizeof(*phdrs) > (unsigned) blocksize) {
ERR_PRT((L"%s : ELF program headers not in first block (%ld)\n", LD_NAME, offs));
return -1;
}
kernel_entry = (VOID *)(elf->e_entry & PADDR_MASK);
phdrs = (Elf64_Phdr *) (buf + offs);
low_addr = ~0;
max_addr = 0;
/*
* allocate chunk table
* Convention: a segment that does not need loading will
* have chunk[].addr = 0.
*/
chunks = (void *)alloc(sizeof(struct segment)*phnum, 0);
if (chunks == NULL) {
ERR_PRT((L"%s : failed alloc chunks %r\n", LD_NAME));
return -1;
}
nchunks = phnum;
/*
* find lowest and higest virtual addresses
* don't assume FULLY sorted !
*/
for (i = 0; i < phnum; ++i) {
/*
* record chunk no matter what because no load may happen
* anywhere in archive, not just as the last segment
*/
paddr = (phdrs[i].p_paddr & PADDR_MASK);
memsz = phdrs[i].p_memsz,
chunks[i].addr = paddr;
chunks[i].offset = phdrs[i].p_offset;
chunks[i].size = phdrs[i].p_filesz;
chunks[i].bss_sz = phdrs[i].p_memsz - phdrs[i].p_filesz;
CHUNK_VALIDATE(i);
if (phdrs[i].p_type != PT_LOAD) {
CHUNK_NO_LOAD(i); /* mark no load chunk */
DBG_PRT((L"%s : skipping segment %ld\n", LD_NAME, i));
continue;
}
CHUNK_CAN_LOAD(i); /* mark no load chunk */
VERB_PRT(3,
Print(L"\n%s : segment %ld vaddr [0x%lx-0x%lx] offset %ld filesz %ld "
"memsz=%ld bss_sz=%ld\n",
LD_NAME, 1+i, chunks[i].addr, chunks[i].addr+phdrs[i].p_filesz,
chunks[i].offset, chunks[i].size, memsz, chunks[i].bss_sz));
if (paddr < low_addr)
low_addr = paddr;
if (paddr + memsz > max_addr)
max_addr = paddr + memsz;
}
if (low_addr & (EFI_PAGE_SIZE - 1)) {
ERR_PRT((L"%s : low_addr not page aligned 0x%lx\n", LD_NAME, low_addr));
goto error;
}
analyze_chunks();
DBG_PRT((L"%s : %d program headers entry=0x%lx\nlowest_addr=0x%lx highest_addr=0x%lx\n",
LD_NAME,
phnum, kernel_entry, low_addr, max_addr));
total_size = (UINTN)max_addr - (UINTN)low_addr;
pages = EFI_SIZE_TO_PAGES(total_size);
/*
* Record end of kernel for initrd
*/
kernel_base = (void *)low_addr;
kernel_end = (void *)(low_addr + (pages << EFI_PAGE_SHIFT));
/* allocate memory for the kernel */
if (alloc_kmem((void *)low_addr, pages) == -1) {
ERR_PRT((L"%s : AllocatePages(%d, 0x%lx) for kernel failed\n",
LD_NAME, pages, low_addr));
ERR_PRT((L"%s : Could not load kernel at 0x%lx\n", LD_NAME, low_addr));
ERR_PRT((L"%s : Bailing\n", LD_NAME));
goto error;
}
return 0;
error:
if (chunks)
free(chunks);
return -1;
}
/*
* Determine which chunk in the Elf file will be coming out of the expand
* code next.
*/
static void
nextchunk(void)
{
int i;
segment_t *cp;
cp = NULL;
for(i=0; i < nchunks; i++) {
if (!CHUNK_IS_VALID(i) || !CHUNK_IS_LOAD(i)) continue;
if (file_offset > chunks[i].offset) continue;
if (cp == NULL || chunks[i].offset < cp->offset) cp = &chunks[i];
}
cur_chunk = cp;
}
/*
* Write the output window window[0..outcnt-1] holding uncompressed
* data and update crc.
*/
void
flush_window(void)
{
static const CHAR8 helicopter[4] = { '|' , '/' , '-' , '\\' };
static UINTN heli_count;
struct segment *cp;
unsigned char *src, *dst;
long cnt;
if (!outcnt) return;
#ifdef DEBUG_GZIP
DBG_PRT((L"%s : flush_window outnct=%d file_offset=%ld\n", LD_NAME, outcnt, file_offset));
#endif
Print(L"%c\b",helicopter[heli_count++%4]);
updcrc(window, outcnt);
/* first time, we extract the headers */
if (!bytes_out) {
if (first_block(window, outcnt) < 0)
error("invalid exec header");
nextchunk();
}
bytes_out += outcnt;
src = window;
tail:
/* check if user wants to abort */
if (check_abort() == EFI_SUCCESS) goto load_abort;
cp = cur_chunk;
if (cp == NULL || file_offset + outcnt <= cp->offset) {
file_offset += outcnt;
return;
}
/* Does this window begin before the current chunk? */
if (file_offset < cp->offset) {
unsigned long skip = cp->offset - file_offset;
src += skip;
file_offset += skip;
outcnt -= skip;
}
dst = (unsigned char *)cp->addr + (file_offset - cp->offset);
cnt = cp->offset + cp->size - file_offset;
if (cnt > outcnt)
cnt = outcnt;
Memcpy(dst, src, cnt);
file_offset += cnt;
outcnt -= cnt;
src += cnt;
/* See if we are at the end of this chunk */
if (file_offset == cp->offset + cp->size) {
if (cp->bss_sz) {
dst = (unsigned char *)cp->addr + cp->size;
Memset(dst, 0, cp->bss_sz);
}
nextchunk();
/* handle remaining bytes */
if (outcnt)
goto tail;
}
return;
load_abort:
free_kmem();
error_return = ELILO_LOAD_ABORTED;
}
static void
error(char *x)
{
ERR_PRT((L"%s : %a", LD_NAME, x));
/* will eventually exit with error from gunzip() */
}
INT32
decompress_kernel(VOID)
{
INT32 ret;
clear_bufs();
makecrc();
Print(L"Uncompressing Linux... ");
ret = gunzip();
if (ret == 0)
Print(L"done\n");
return ret == 0 ? 0 : -1;
}
int
gunzip_kernel(fops_fd_t fd, kdesc_t *kd)
{
int ret = -1;
error_return = ELILO_LOAD_ERROR;
window = (void *)alloc(WSIZE, 0);
if (window == NULL) {
ERR_PRT((L"%s : allocate output window failed\n", LD_NAME));
return -1;
}
inbuf = (void *)alloc(INBUFSIZE, 0);
if (inbuf == NULL) {
ERR_PRT((L"%s : allocate input window failedr\n", LD_NAME));
goto error;
}
input_fd = fd;
insize = 0;
bytes_out = 0;
ret = decompress_kernel();
error:
if (window) free(window);
if (inbuf) free(inbuf);
if (ret == 0) {
kd->kentry = kernel_entry;
kd->kend = kernel_end;
kd->kstart = kernel_base;
error_return = ELILO_LOAD_SUCCESS;
}
return error_return;
}
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