p_vmlinx.cpp

UPX 源代码

    stxt->sh_addralign = 4;
    stxt->sh_size += sizeof(stub_arm_linux_kernel_vmlinux_head);

    return sizeof(stub_arm_linux_kernel_vmlinux_head);
}

unsigned PackVmlinuxARMEB::write_vmlinux_head(
    OutputFile *const fo,
    Shdr *const stxt
)
{
    // First word from vmlinux-head.S
    fo->write(&stub_armeb_linux_kernel_vmlinux_head[0], 4);

    // Second word
    U32 tmp_u32;
    unsigned const t = (0xff000000 &
            BeLePolicy::get32(&stub_armeb_linux_kernel_vmlinux_head[4]))
        | (0x00ffffff & (0u - 1 + ((3+ ph.c_len)>>2)));
    tmp_u32 = t;
    fo->write(&tmp_u32, 4);

    stxt->sh_addralign = 4;
    stxt->sh_size += sizeof(stub_armeb_linux_kernel_vmlinux_head);

    return sizeof(stub_armeb_linux_kernel_vmlinux_head);
}

unsigned PackVmlinuxPPC32::write_vmlinux_head(
    OutputFile * /*const fo*/,
    Shdr * /*const stxt*/
)
{
    return 0;
}


bool PackVmlinuxARMEL::has_valid_vmlinux_head()
{
    U32 buf[2];
    fi->seek(p_text->sh_offset + sizeof(stub_arm_linux_kernel_vmlinux_head) -8, SEEK_SET);
    fi->readx(buf, sizeof(buf));
    //unsigned const word0 = buf[0];
    unsigned const word1 = buf[1];
    if (0xeb==(word1>>24)
    &&  (0x00ffffff& word1)==(0u - 1 + ((3+ ph.c_len)>>2))) {
        return true;
    }
    return false;
}

bool PackVmlinuxARMEB::has_valid_vmlinux_head()
{
    U32 buf[2];
    fi->seek(p_text->sh_offset + sizeof(stub_armeb_linux_kernel_vmlinux_head) -8, SEEK_SET);
    fi->readx(buf, sizeof(buf));
    //unsigned const word0 = buf[0];
    unsigned const word1 = buf[1];
    if (0xeb==(word1>>24)
    &&  (0x00ffffff& word1)==(0u - 1 + ((3+ ph.c_len)>>2))) {
        return true;
    }
    return false;
}

bool PackVmlinuxPPC32::has_valid_vmlinux_head()
{
    U32 buf[2];
    fi->seek(p_text->sh_offset + sizeof(stub_powerpc_linux_kernel_vmlinux_head) -8, SEEK_SET);
    fi->readx(buf, sizeof(buf));
    //unsigned const word0 = buf[0];
    unsigned const word1 = buf[1];
    if (0xeb==(word1>>24)
    &&  (0x00ffffff& word1)==(0u - 1 + ((3+ ph.c_len)>>2))) {
        return true;
    }
    return false;
}

bool PackVmlinuxI386::has_valid_vmlinux_head()
{
    unsigned char buf[5];
    fi->seek(p_text->sh_offset + sizeof(stub_i386_linux_kernel_vmlinux_head) -5, SEEK_SET);
    fi->readx(&buf[0], 5);
    if (0xE8!=buf[0] ||  BeLePolicy::get32(&buf[1]) != ph.c_len)
    {
        return false;
    }
    return true;
}

bool PackVmlinuxAMD64::has_valid_vmlinux_head()
{
    unsigned char buf[5];
    fi->seek(p_text->sh_offset + sizeof(stub_amd64_linux_kernel_vmlinux_head) -5, SEEK_SET);
    fi->readx(&buf[0], 5);
    if (0xE8!=buf[0] ||  BeLePolicy::get32(&buf[1]) != ph.c_len)
    {
        return false;
    }
    return true;
}

//
// Example usage within build system of Linux kernel-2.6.18:
//
//----- arch/i386/boot/compressed/Makefile
//#
//# linux/arch/i386/boot/compressed/Makefile
//#
//# create a compressed vmlinux image from the original vmlinux
//#
//
//targets := vmlinux upx-piggy.o
//
//LDFLAGS_vmlinux := -Ttext $(IMAGE_OFFSET) -e startup_32
//
//$(obj)/vmlinux: $(obj)/upx-piggy.o FORCE
//	$(call if_changed,ld)
//	@:
//
//$(obj)/upx-piggy.o: vmlinux FORCE
//	upx --lzma -f -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-piggy.o
//#              boot/vmlinux.bin     by objcopy
//#              boot/bzImage         by arch/i386/boot/tools/build with
//#                                     bootsect and setup
//#
//-----

#if 0  /*{*/
// For Debian nslu2-linux (2.6.19), only this Makefile changes:
--- ./debian/build/build-arm-none-ixp4xx/arch/arm/boot/compressed/Makefile.orig	2006-11-29 13:57:37.000000000 -0800
+++ ./debian/build/build-arm-none-ixp4xx/arch/arm/boot/compressed/Makefile	2006-12-16 02:39:38.000000000 -0800
@@ -5,7 +5,7 @@
 #

 HEAD	= head.o
-OBJS	= misc.o
+OBJS	=
 FONTC	= drivers/video/console/font_acorn_8x8.c

 FONT = $(addprefix ../../../../drivers/video/console/, font_acorn_8x8.o)
@@ -73,8 +73,8 @@

 SEDFLAGS	= s/TEXT_START/$(ZTEXTADDR)/;s/BSS_START/$(ZBSSADDR)/

-targets       := vmlinux vmlinux.lds piggy.gz piggy.o $(FONT) \
-		 head.o misc.o $(OBJS)
+targets       := vmlinux vmlinux.lds upx-piggy.o $(FONT) \
+		 head.o $(OBJS)
 EXTRA_CFLAGS  := -fpic
 EXTRA_AFLAGS  :=

@@ -95,20 +95,16 @@
 # would otherwise mess up our GOT table
 CFLAGS_misc.o := -Dstatic=

-$(obj)/vmlinux: $(obj)/vmlinux.lds $(obj)/$(HEAD) $(obj)/piggy.o \
-	 	$(addprefix $(obj)/, $(OBJS)) FORCE
+$(obj)/vmlinux: $(obj)/vmlinux.lds $(obj)/$(HEAD) \
+	 	$(addprefix $(obj)/, $(OBJS)) $(obj)/upx-piggy.o FORCE
 	$(call if_changed,ld)
 	@:

-$(obj)/piggy.gz: $(obj)/../Image FORCE
-	$(call if_changed,gzip)
-
-$(obj)/piggy.o:  $(obj)/piggy.gz FORCE
+$(obj)/upx-piggy.o:  vmlinux FORCE
+	upx --lzma -f -o $@ $<; touch $@

 CFLAGS_font_acorn_8x8.o := -Dstatic=

 $(obj)/vmlinux.lds: $(obj)/vmlinux.lds.in arch/arm/boot/Makefile .config
 	@sed "$(SEDFLAGS)" < $< > $@

-$(obj)/misc.o: $(obj)/misc.c include/asm/arch/uncompress.h lib/inflate.c
-
#endif  /*}*/

// Approximate translation for Linux 2.4.x:
// - - -
// arch/i386/Makefile: LD_FLAGS=-e startup_32
//----- arch/i386/boot/compressed/Makefile
//# linux/arch/i386/boot/compressed/Makefile
//#
//# create a compressed vmlinux image from the original vmlinux
//#
//
//HEAD =
//SYSTEM = $(TOPDIR)/vmlinux
//
//OBJECTS = $(HEAD)
//
//ZLDFLAGS = -e startup_32
//
//#
//# ZIMAGE_OFFSET is the load offset of the compression loader
//# BZIMAGE_OFFSET is the load offset of the high loaded compression loader
//#
//ZIMAGE_OFFSET = 0x1000
//BZIMAGE_OFFSET = 0x100000
//
//ZLINKFLAGS = -Ttext $(ZIMAGE_OFFSET) $(ZLDFLAGS)
//BZLINKFLAGS = -Ttext $(BZIMAGE_OFFSET) $(ZLDFLAGS)
//
//all: vmlinux
//
//vmlinux: upx-piggy.o $(OBJECTS)
//  $(LD) $(ZLINKFLAGS) -o vmlinux $(OBJECTS) upx-piggy.o
//
//bvmlinux: upx-piggy.o $(OBJECTS)
//  $(LD) $(BZLINKFLAGS) -o bvmlinux $(OBJECTS) upx-piggy.o
//
//upx-piggy.o:  $(SYSTEM)
//  $(RM) -f $@
//  upx --best -o $@ $<
//  touch $@
//
//clean:
//  rm -f vmlinux bvmlinux _tmp_*
//-----

//
// Example test jig:
//  $ gcc -m32 -o test-piggy -nostartfiles -nostdlib test-piggy.o piggy.o
//  $ gdb test-piggy
//  (gdb) run >dumped
//  (gdb)  /* Execute [single step, etc.; the decompressor+unfilter moves!]
//          * until reaching the 'lret' at the end of unfilter.
//          */
//  (gdb) set $pc= &dump
//  (gdb) stepi
//  (gdb) set $edx=<actual_uncompressed_length>
//  (gdb) continue
//  (gdb) q
//  $ # Compare file 'dumped' with the portion of vmlinux that made piggy.o.
//  $ dd if=vmlinux bs=<leader_size> skip=1  |  cmp - dumped
//  cmp: EOF on dumped
//  $
//----- test-piggy.S
//#include <asm/mman.h>
//#include <asm/unistd.h>
//
//dump:
//      movl $0x456789,%edx  # length  MODIFY THIS VALUE TO SUIT YOUR CASE
//      movl $0x100000,%ecx  # base
//      movl $1,%ebx         # stdout
//      movl $ __NR_write,%eax
//      int $0x80
//      nop
//      hlt
//mmap:
//      pushl %ebx
//      leal 2*4(%esp),%ebx
//      pushl $ __NR_mmap; popl %eax
//      int $0x80
//      popl %ebx
//      ret $6*4
//
//_start: .globl _start
//      nop
//      int3  # enter debugger!
//      pushl $0
//      pushl $0
//      pushl $ MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED
//      pushl $ PROT_EXEC | PROT_WRITE | PROT_READ
//      pushl $0x600000  # 6MB length
//      pushl $0x100000  # 1MB address
//      call mmap
//      leal -0x9000(%esp),%esi  # expect "lea 0x9000(%esi),%esp" later
///* Fall into .text of upx-compressed vmlinux. */
//-----

// Example test jig for ARM:
//-----main.c
//unsigned work[(1<<16)/sizeof(unsigned)];
//unsigned kernel[(3<<20)/sizeof(unsigned)];
//
///* In order to avoid complaints such as
//     /usr/bin/ld: ERROR: libgcc_s.so uses hardware FP, whereas main uses software FP
//   when building this test program, then you must change the .e_flags
//   in the header of the compressed, relocatble output from upx, from
//      Flags: 0x202, has entry point, GNU EABI, software FP
//   to
//      Flags: 0x0
//*/
//
//main()
//{
//        char *const end = decompress_kernel(kernel, work, (1<<(16-2))+work, 0x1234);
//        write(1, kernel, (char *)end - (char *)kernel);
//        return 0;
//}
//-----


/*************************************************************************
//
**************************************************************************/

const int *PackVmlinuxAMD64::getCompressionMethods(int method, int level) const
{
    return Packer::getDefaultCompressionMethods_le32(method, level);
}


const int *PackVmlinuxAMD64::getFilters() const
{
    static const int filters[] = {
        0x49, 0x46,
    -1 };
    return filters;
}

bool PackVmlinuxAMD64::is_valid_e_entry(Addr e_entry)
{
    return 0x200000<=e_entry; // 2MB
}

Linker* PackVmlinuxAMD64::newLinker() const
{
    return new ElfLinkerX86;
}



// instantiate instances
template class PackVmlinuxBase<ElfClass_LE32>;
template class PackVmlinuxBase<ElfClass_BE32>;
template class PackVmlinuxBase<ElfClass_LE64>;


/*
vi:ts=4:et
*/