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* Can't execute any MIPS  binary
@ 2008-02-12 23:34 Matteo Croce
       [not found] ` <47B22E4F.4070308@vudu.com>
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Matteo Croce @ 2008-02-12 23:34 UTC (permalink / raw)
  To: linux-mips

Hi,
I have a machine, an AR7 MIPS router I want to hack, but I'm unable
to run _any_ executable on that machine outside the ones in the firmware.
I tried building a static mips1 binary, but it fails so:

# /var/test.bin
/var/test.bin: 1: Syntax error: "(" unexpected

so I downloaded a binary builtin in the firmware and I compared it to my own:

$ file busybox.bin test.bin
busybox.bin: ELF 32-bit LSB executable, MIPS, MIPS-I version 1 (SYSV), dynamically linked (uses shared libs), stripped
test.bin:    ELF 32-bit LSB executable, MIPS, version 1 (SYSV), statically linked, stripped

busybox.bin is the builtin busybox while test.bin is a static HelloWorld

I ran readelf on it:

$ readelf -h busybox.bin
ELF Header:
  Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
  Class:                             ELF32
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              EXEC (Executable file)
  Machine:                           MIPS R3000
  Version:                           0x1
  Entry point address:               0x4037e0
  Start of program headers:          52 (bytes into file)
  Start of section headers:          337304 (bytes into file)
  Flags:                             0x5, noreorder, cpic, mips1
  Size of this header:               52 (bytes)
  Size of program headers:           32 (bytes)
  Number of program headers:         6
  Size of section headers:           40 (bytes)
  Number of section headers:         21
  Section header string table index: 20
$ readelf -h test.bin
ELF Header:
  Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
  Class:                             ELF32
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              EXEC (Executable file)
  Machine:                           MIPS R3000
  Version:                           0x1
  Entry point address:               0x400140
  Start of program headers:          52 (bytes into file)
  Start of section headers:          11780 (bytes into file)
  Flags:                             0x50001007, noreorder, pic, cpic, o32, mips32
  Size of this header:               52 (bytes)
  Size of program headers:           32 (bytes)
  Number of program headers:         3
  Size of section headers:           40 (bytes)
  Number of section headers:         17
  Section header string table index: 16
$ diff -u <(readelf -h busybox.bin) <(readelf -h test.bin)
--- /dev/fd/63  2008-02-13 00:26:48.880261477 +0100
+++ /dev/fd/62  2008-02-13 00:26:48.880261477 +0100
@@ -8,13 +8,13 @@
   Type:                              EXEC (Executable file)
   Machine:                           MIPS R3000
   Version:                           0x1
-  Entry point address:               0x4037e0
+  Entry point address:               0x400140
   Start of program headers:          52 (bytes into file)
-  Start of section headers:          337304 (bytes into file)
-  Flags:                             0x5, noreorder, cpic, mips1
+  Start of section headers:          11780 (bytes into file)
+  Flags:                             0x50001007, noreorder, pic, cpic, o32, mips32
   Size of this header:               52 (bytes)
   Size of program headers:           32 (bytes)
-  Number of program headers:         6
+  Number of program headers:         3
   Size of section headers:           40 (bytes)
-  Number of section headers:         21
-  Section header string table index: 20
+  Number of section headers:         17
+  Section header string table index: 16

The router firmware uses:
# cat /proc/version
Linux version 2.4.17_mvl21-malta-mips_fp_le (root@localhost.localdomain) (gcc version 2.95.3 20010315 (release/MontaVista)) #1 Fri Mar 18 11:00:12 EST 2005

While I have a gcc-4.2.3 toolchain with 2.6.24 headers.


How can I build a mips1 binary instead of the mips32 I make? Can I disable o32?

Best Regards,
Matteo Croce

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Can't execute any MIPS  binary
       [not found] ` <47B22E4F.4070308@vudu.com>
@ 2008-02-12 23:49   ` Matteo Croce
  0 siblings, 0 replies; 6+ messages in thread
From: Matteo Croce @ 2008-02-12 23:49 UTC (permalink / raw)
  To: Edin Hodzic; +Cc: linux-mips

[-- Attachment #1: Type: text/plain, Size: 4803 bytes --]

Il Wednesday 13 February 2008 00:39:59 Edin Hodzic ha scritto:
> -march=mips1 or -mips1 should do the trick, no?
> 
> Dino
> 
> On 02/12/2008 03:34 PM, Matteo Croce said:
> > Hi,
> > I have a machine, an AR7 MIPS router I want to hack, but I'm unable
> > to run _any_ executable on that machine outside the ones in the firmware.
> > I tried building a static mips1 binary, but it fails so:
> >
> > # /var/test.bin
> > /var/test.bin: 1: Syntax error: "(" unexpected
> >
> > so I downloaded a binary builtin in the firmware and I compared it to my own:
> >
> > $ file busybox.bin test.bin
> > busybox.bin: ELF 32-bit LSB executable, MIPS, MIPS-I version 1 (SYSV), dynamically linked (uses shared libs), stripped
> > test.bin:    ELF 32-bit LSB executable, MIPS, version 1 (SYSV), statically linked, stripped
> >
> > busybox.bin is the builtin busybox while test.bin is a static HelloWorld
> >
> > I ran readelf on it:
> >
> > $ readelf -h busybox.bin
> > ELF Header:
> >   Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
> >   Class:                             ELF32
> >   Data:                              2's complement, little endian
> >   Version:                           1 (current)
> >   OS/ABI:                            UNIX - System V
> >   ABI Version:                       0
> >   Type:                              EXEC (Executable file)
> >   Machine:                           MIPS R3000
> >   Version:                           0x1
> >   Entry point address:               0x4037e0
> >   Start of program headers:          52 (bytes into file)
> >   Start of section headers:          337304 (bytes into file)
> >   Flags:                             0x5, noreorder, cpic, mips1
> >   Size of this header:               52 (bytes)
> >   Size of program headers:           32 (bytes)
> >   Number of program headers:         6
> >   Size of section headers:           40 (bytes)
> >   Number of section headers:         21
> >   Section header string table index: 20
> > $ readelf -h test.bin
> > ELF Header:
> >   Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
> >   Class:                             ELF32
> >   Data:                              2's complement, little endian
> >   Version:                           1 (current)
> >   OS/ABI:                            UNIX - System V
> >   ABI Version:                       0
> >   Type:                              EXEC (Executable file)
> >   Machine:                           MIPS R3000
> >   Version:                           0x1
> >   Entry point address:               0x400140
> >   Start of program headers:          52 (bytes into file)
> >   Start of section headers:          11780 (bytes into file)
> >   Flags:                             0x50001007, noreorder, pic, cpic, o32, mips32
> >   Size of this header:               52 (bytes)
> >   Size of program headers:           32 (bytes)
> >   Number of program headers:         3
> >   Size of section headers:           40 (bytes)
> >   Number of section headers:         17
> >   Section header string table index: 16
> > $ diff -u <(readelf -h busybox.bin) <(readelf -h test.bin)
> > --- /dev/fd/63  2008-02-13 00:26:48.880261477 +0100
> > +++ /dev/fd/62  2008-02-13 00:26:48.880261477 +0100
> > @@ -8,13 +8,13 @@
> >    Type:                              EXEC (Executable file)
> >    Machine:                           MIPS R3000
> >    Version:                           0x1
> > -  Entry point address:               0x4037e0
> > +  Entry point address:               0x400140
> >    Start of program headers:          52 (bytes into file)
> > -  Start of section headers:          337304 (bytes into file)
> > -  Flags:                             0x5, noreorder, cpic, mips1
> > +  Start of section headers:          11780 (bytes into file)
> > +  Flags:                             0x50001007, noreorder, pic, cpic, o32, mips32
> >    Size of this header:               52 (bytes)
> >    Size of program headers:           32 (bytes)
> > -  Number of program headers:         6
> > +  Number of program headers:         3
> >    Size of section headers:           40 (bytes)
> > -  Number of section headers:         21
> > -  Section header string table index: 20
> > +  Number of section headers:         17
> > +  Section header string table index: 16
> >
> > The router firmware uses:
> > # cat /proc/version
> > Linux version 2.4.17_mvl21-malta-mips_fp_le (root@localhost.localdomain) (gcc version 2.95.3 20010315 (release/MontaVista)) #1 Fri Mar 18 11:00:12 EST 2005
> >
> > While I have a gcc-4.2.3 toolchain with 2.6.24 headers.
> >
> >
> > How can I build a mips1 binary instead of the mips32 I make? Can I disable o32?
> >
> > Best Regards,
> > Matteo Croce
> >
> >   
> 

Already tried, won't work.
I attach the binaries

[-- Attachment #2: test.bin --]
[-- Type: application/x-executable, Size: 22085 bytes --]

[-- Attachment #3: busybox.bin --]
[-- Type: application/x-executable, Size: 338144 bytes --]

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Can't execute any MIPS  binary
  2008-02-12 23:34 Can't execute any MIPS binary Matteo Croce
       [not found] ` <47B22E4F.4070308@vudu.com>
@ 2008-02-12 23:54 ` David Daney
  2008-02-13 16:21   ` Matteo Croce
  2008-02-21 22:40 ` Michael Wood
  2 siblings, 1 reply; 6+ messages in thread
From: David Daney @ 2008-02-12 23:54 UTC (permalink / raw)
  To: Matteo Croce; +Cc: linux-mips

Matteo Croce wrote:
> Hi,
> I have a machine, an AR7 MIPS router I want to hack, but I'm unable
> to run _any_ executable on that machine outside the ones in the firmware.
> I tried building a static mips1 binary, but it fails so:
> 
> # /var/test.bin
> /var/test.bin: 1: Syntax error: "(" unexpected
> 
> so I downloaded a binary builtin in the firmware and I compared it to my own:
> 
> $ file busybox.bin test.bin
> busybox.bin: ELF 32-bit LSB executable, MIPS, MIPS-I version 1 (SYSV), dynamically linked (uses shared libs), stripped
> test.bin:    ELF 32-bit LSB executable, MIPS, version 1 (SYSV), statically linked, stripped
> 
> busybox.bin is the builtin busybox while test.bin is a static HelloWorld
> 
> I ran readelf on it:
> 
> $ readelf -h busybox.bin
> ELF Header:
>   Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
>   Class:                             ELF32
>   Data:                              2's complement, little endian
>   Version:                           1 (current)
>   OS/ABI:                            UNIX - System V
>   ABI Version:                       0
>   Type:                              EXEC (Executable file)
>   Machine:                           MIPS R3000
>   Version:                           0x1
>   Entry point address:               0x4037e0
>   Start of program headers:          52 (bytes into file)
>   Start of section headers:          337304 (bytes into file)
>   Flags:                             0x5, noreorder, cpic, mips1
>   Size of this header:               52 (bytes)
>   Size of program headers:           32 (bytes)
>   Number of program headers:         6
>   Size of section headers:           40 (bytes)
>   Number of section headers:         21
>   Section header string table index: 20
> $ readelf -h test.bin
> ELF Header:
>   Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
>   Class:                             ELF32
>   Data:                              2's complement, little endian
>   Version:                           1 (current)
>   OS/ABI:                            UNIX - System V
>   ABI Version:                       0
>   Type:                              EXEC (Executable file)
>   Machine:                           MIPS R3000
>   Version:                           0x1
>   Entry point address:               0x400140
>   Start of program headers:          52 (bytes into file)
>   Start of section headers:          11780 (bytes into file)
>   Flags:                             0x50001007, noreorder, pic, cpic, o32, mips32
>   Size of this header:               52 (bytes)
>   Size of program headers:           32 (bytes)
>   Number of program headers:         3
>   Size of section headers:           40 (bytes)
>   Number of section headers:         17
>   Section header string table index: 16
> $ diff -u <(readelf -h busybox.bin) <(readelf -h test.bin)
> --- /dev/fd/63  2008-02-13 00:26:48.880261477 +0100
> +++ /dev/fd/62  2008-02-13 00:26:48.880261477 +0100
> @@ -8,13 +8,13 @@
>    Type:                              EXEC (Executable file)
>    Machine:                           MIPS R3000
>    Version:                           0x1
> -  Entry point address:               0x4037e0
> +  Entry point address:               0x400140
>    Start of program headers:          52 (bytes into file)
> -  Start of section headers:          337304 (bytes into file)
> -  Flags:                             0x5, noreorder, cpic, mips1
> +  Start of section headers:          11780 (bytes into file)
> +  Flags:                             0x50001007, noreorder, pic, cpic, o32, mips32
>    Size of this header:               52 (bytes)
>    Size of program headers:           32 (bytes)
> -  Number of program headers:         6
> +  Number of program headers:         3
>    Size of section headers:           40 (bytes)
> -  Number of section headers:         21
> -  Section header string table index: 20
> +  Number of section headers:         17
> +  Section header string table index: 16
> 
> The router firmware uses:
> # cat /proc/version
> Linux version 2.4.17_mvl21-malta-mips_fp_le (root@localhost.localdomain) (gcc version 2.95.3 20010315 (release/MontaVista)) #1 Fri Mar 18 11:00:12 EST 2005
> 

IIRC, the definitions of the elf flags were wrong in 2.4.x (x < 20 or 25 
or something like that).  I had similar problems.

You should be able to run the binary if run a binary editor on it and 
clear the mips32 flag (i.e. change the flags from 0x50001007 to just 
0x1007).

If you want to generate the program with out the mips32 flag in the 
first place you have to compile everything (libc, libgcc crt*.o, program 
) with -mips1

It may be easier to run a program that post processes the executable to 
clear the flag.


David Daney

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Can't execute any MIPS  binary
  2008-02-12 23:54 ` David Daney
@ 2008-02-13 16:21   ` Matteo Croce
  2008-02-13 17:31     ` David Daney
  0 siblings, 1 reply; 6+ messages in thread
From: Matteo Croce @ 2008-02-13 16:21 UTC (permalink / raw)
  To: David Daney; +Cc: linux-mips

Il Wednesday 13 February 2008 00:54:21 hai scritto:
> You should be able to run the binary if run a binary editor on it and 
> clear the mips32 flag (i.e. change the flags from 0x50001007 to just 
> 0x1007).

Solved by changing flags from 0x50001007 to 0x5, thanks :)

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Can't execute any MIPS  binary
  2008-02-13 16:21   ` Matteo Croce
@ 2008-02-13 17:31     ` David Daney
  0 siblings, 0 replies; 6+ messages in thread
From: David Daney @ 2008-02-13 17:31 UTC (permalink / raw)
  To: Matteo Croce; +Cc: linux-mips

Matteo Croce wrote:
> Il Wednesday 13 February 2008 00:54:21 hai scritto:
>> You should be able to run the binary if run a binary editor on it and 
>> clear the mips32 flag (i.e. change the flags from 0x50001007 to just 
>> 0x1007).
> 
> Solved by changing flags from 0x50001007 to 0x5, thanks :)

I think that you only want to clear the mips32 part (that is the part 
keeping the elf exec from working).  I would leave all the other bits as 
they were.

In other words, probably the flags should be 0x1007, instead of 0x5.

Although it may not really matter.  It has been several years since I 
studied the code.

David Daney

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Can't execute any MIPS binary
  2008-02-12 23:34 Can't execute any MIPS binary Matteo Croce
       [not found] ` <47B22E4F.4070308@vudu.com>
  2008-02-12 23:54 ` David Daney
@ 2008-02-21 22:40 ` Michael Wood
  2 siblings, 0 replies; 6+ messages in thread
From: Michael Wood @ 2008-02-21 22:40 UTC (permalink / raw)
  To: Matteo Croce; +Cc: linux-mips

Hi

On Wed, Feb 13, 2008 at 1:34 AM, Matteo Croce <rootkit85@yahoo.it> wrote:
> Hi,
>  I have a machine, an AR7 MIPS router I want to hack, but I'm unable
>  to run _any_ executable on that machine outside the ones in the firmware.
>  I tried building a static mips1 binary, but it fails so:
>
>  # /var/test.bin
>  /var/test.bin: 1: Syntax error: "(" unexpected

I had the exact same problem.

As far as I remember I had to make sure to build uclibc for MIPS-I,
because if I built a MIPS-I object file and linked it to a uclibc that
was not built for MIPS-I, it would give those errors.

I have just found my change to the OpenWrt wiki (on the WRTP54G page):
http://wiki.openwrt.org/OpenWrtDocs/Hardware/Linksys/WRTP54G?action=diff&rev2=171&rev1=170

-- 
Michael Wood <esiotrot@gmail.com>

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2008-02-21 22:40 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-02-12 23:34 Can't execute any MIPS binary Matteo Croce
     [not found] ` <47B22E4F.4070308@vudu.com>
2008-02-12 23:49   ` Matteo Croce
2008-02-12 23:54 ` David Daney
2008-02-13 16:21   ` Matteo Croce
2008-02-13 17:31     ` David Daney
2008-02-21 22:40 ` Michael Wood

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