Master/upx
1
0
Fork 0
Code Issues Pull Requests Actions 1 Packages Projects Releases Wiki Activity

vmlinux/i386: fix filters, 0x400000 start, integration with kernel build

Browse Source
This commit is contained in:
John Reiser
2006-10-14 14:52:30 -07:00
parent b31b8cd7f0
commit 6891bc3da3
4 changed files with 120 additions and 46 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/p_vmlinx.cpp
+73 -45
View File
@@ -65,11 +65,22 @@ const int *PackVmlinuxI386::getCompressionMethods(int method, int level) const
const int *PackVmlinuxI386::getFilters() const
{
static const int filters[] = {
0x49,
0x49, 0x46,
-1 };
return filters;
}
// copied from PackUnix 2006-10-13.
int PackVmlinuxI386::getStrategy(Filter &/*ft*/)
{
// Called just before reading and compressing each block.
// Might want to adjust blocksize, etc.
// If user specified the filter, then use it (-2==strategy).
// Else try the first two filters, and pick the better (2==strategy).
return (opt->no_filter ? -3 : ((opt->filter > 0) ? -2 : 2));
}
static int __acc_cdecl_qsort
compare_Phdr(void const *aa, void const *bb)
{
@@ -102,6 +113,12 @@ compare_Phdr(void const *aa, void const *bb)
// LOAD 0x249000 0x02348000 0x02348000 0x81800 0xcb0fc RWE 0x1000
// STACK 0x000000 0x00000000 0x00000000 0x00000 0x00000 RWE 0x4
//
//----- kernel-2.6.18-1.2778 Fedora Core 6 test 3
//Program Headers(3)
// Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
// LOAD 0x001000 0xc0400000 0x00400000 0x279820 0x279820 R E 0x1000
// LOAD 0x27b000 0xc067a000 0x0067a000 0x10ee64 0x1b07e8 RWE 0x1000
// NOTE 0x000000 0x00000000 0x00000000 0x00000 0x00000 R 0x4
bool PackVmlinuxI386::canPack()
{
@@ -121,7 +138,7 @@ bool PackVmlinuxI386::canPack()
|| ehdri.e_phoff != sizeof(ehdri) // Phdrs not contiguous with Ehdr
|| ehdri.e_phentsize!=sizeof(Elf32_Phdr)
|| ehdri.e_type!=Elf32_Ehdr::ET_EXEC
|| 0x00100000!=(0x001fffff & ehdri.e_entry) // entry not an odd 1MB
|| 0!=(0x000fffff & ehdri.e_entry) // entry not on whole 1MB
) {
return false;
}
@@ -190,8 +207,10 @@ int PackVmlinuxI386::buildLoader(const Filter *ft)
static bool defineFilterSymbols(Linker *linker, const Filter *ft)
{
if (ft->id == 0)
if (ft->id == 0) {
linker->defineSymbol("filter_length", 0);
return false;
}
assert(ft->calls > 0);
linker->defineSymbol("filter_cto", ft->cto);
@@ -245,7 +264,7 @@ void PackVmlinuxI386::pack(OutputFile *fo)
upx_compress_config_t cconf; cconf.reset();
// limit stack size needed for runtime decompression
cconf.conf_lzma.max_num_probs = 1846 + (768 << 4); // ushort: ~28KB stack
compressWithFilters(&ft, 512, 0, NULL, &cconf);
compressWithFilters(&ft, 512, getStrategy(ft), getFilters(), &cconf);
const unsigned lsize = getLoaderSize();
@@ -268,11 +287,23 @@ void PackVmlinuxI386::pack(OutputFile *fo)
shdro[1].sh_size = 1+ 4+ ph.c_len + lsize;
shdro[1].sh_addralign = 1;
unsigned char const call = 0xE8; // opcode for CALL d32
fo->write(&call, 1); fo_off+=1;
tmp_le32 = ph.c_len; fo->write(&tmp_le32, 4); fo_off += 4;
fo->write(obuf, ph.c_len); fo_off += ph.c_len;
fo->write(loader, lsize); fo_off += lsize;
{
static const
#include "stub/i386-linux.kernel.head-vmlinux.h"
// ENTRY_POINT
fo->write(&head_stack[0], sizeof(head_stack)-2*(1+ 4) +1);
tmp_le32 = ehdri.e_entry; fo->write(&tmp_le32, 4);
// COMPRESSED_LENGTH
fo->write(&head_stack[sizeof(head_stack)-(1+ 4)], 1);
tmp_le32 = ph.c_len; fo->write(&tmp_le32, 4);
fo_off += sizeof(head_stack);
fo->write(obuf, ph.c_len); fo_off += ph.c_len;
fo->write(loader, lsize); fo_off += lsize;
}
#if 0
printf("%-13s: compressed : %8u bytes\n", getName(), ph.c_len);
@@ -495,7 +526,7 @@ void PackVmlinuxI386::unpack(OutputFile *fo)
}
//
// Example usage within build system of Linux kernel-2.6.7:
// Example usage within build system of Linux kernel-2.6.18:
//
//----- arch/i386/boot/compressed/Makefile
//#
@@ -507,7 +538,6 @@ void PackVmlinuxI386::unpack(OutputFile *fo)
//targets := vmlinux upx-head.o upx-piggy.o
//
//LDFLAGS_vmlinux := -Ttext $(IMAGE_OFFSET) -e startup_32
//EXTRA_AFLAGS += -DIMAGE_OFFSET=$(IMAGE_OFFSET)
//
//$(obj)/vmlinux: $(obj)/upx-head.o $(obj)/upx-piggy.o FORCE
// $(call if_changed,ld)
@@ -517,44 +547,42 @@ void PackVmlinuxI386::unpack(OutputFile *fo)
// rm -f $@
// upx --best -o $@ $<
// touch $@
//
//#
//# The ORIGINAL build sequence using gzip is:
//# vmlinux Elf executable at top level in tree
//# (in same directory as MAINTAINERS)
//# In arch/i386:
//# boot/compressed/vmlinux.bin by objcopy -O binary
//# boot/compressed/vmlinux.bin.gz by gzip
//# boot/compressed/piggy.o by ld --format binary --oformat elf32-i386
//#
//# The 3 steps above create a linkable
//# compressed blob.
//# In arch/i386:
//# boot/compressed/vmlinux by ld head.o misc.o piggy.o
//# boot/vmlinux.bin by objcopy
//# boot/bzImage by arch/i386/boot/tools/build with
//# bootsect and setup
//#
//#
//# The MODIFIED build sequence using upx is:
//# vmlinux Elf executable at top level in tree
//# (in same directory as MAINTAINERS)
//# In arch/i386:
//# boot/compressed/upx-piggy.o by upx format vmlinux/386
//#
//# In arch/i386/boot:
//# boot/compressed/vmlinux by ld upx-head.o upx-piggy.o
//# boot/vmlinux.bin by objcopy
//# boot/bzImage by arch/i386/boot/tools/build with
//# bootsect and setup
//#
//-----
//
//----- arch/i386/boot/compressed/upx-head.S
// .text
//startup_32: .globl startup_32 # In: %esi=0x90000 setup data "real_mode pointer"
// #cli # this must be true already
//
// /* The only facts about segments here, that are true for all kernels:
// * %cs is a valid "flat" code segment; no other segment reg is valid;
// * the next segment after %cs is a valid "flat" data segment, but
// * no segment register designates it yet.
// */
// movl %cs,%eax; addl $1<<3,%eax # the next segment after %cs
// movl %eax,%ds
// movl %eax,%es
// leal 0x9000(%esi),%ecx # 0x99000 typical
// movl %ecx,-8(%ecx) # 32-bit offset for stack pointer
// movl %eax,-4(%ecx) # segment for stack pointer
// lss -8(%ecx),%esp # %ss:%esp= %ds:0x99000
// /* Linux Documentation/i386/boot.txt "SAMPLE BOOT CONFIGURATION" says
// 0x8000-0x8FFF Stack and heap [inside the "real mode segment",
// just below the command line at offset 0x9000].
//
// arch/i386/boot/compressed/head.S "Do the decompression ..." says
// %esi contains the "real mode pointer" [as a 32-bit addr].
//
// In any case, avoid EBDA (Extended BIOS Data Area) below 0xA0000.
// boot.txt says 0x9A000 is the limit. LILO goes up to 0x9B000.
// */
//
// pushl $0; popf # subsumes "cli; cld"; also clears NT for buggy BIOS
//
//#ifndef IMAGE_OFFSET /*{*/
//#define IMAGE_OFFSET 0x100000
//#endif /*}*/
// movl $ IMAGE_OFFSET,%eax # destination of uncompression (and entry point)
// push %cs
/* Fall into .text of upx-compressed vmlinux. */
// /* All code is in stub/src/i386-linux.kernel.head-vmlinux.S */
//-----
// Approximate translation for Linux 2.4.x: