question about "Failed to execute /init"

[Nick Clifton]

Hi Sandeep, Hi Loody,

 > Sandeep K Sinha wrote:
> You should have asked this at the bunutils list.

Actually I do not think that this is a binutils question.  It is a 
question for the kernel folks.  But I'll try to answer it anyway.

> loody wrote:
>>> my init is a very simple program like below
>>>
>>> #include <stdio.h>
>>> int main()
>>> {
>>>        printf("hello world\n");
>>>        sleep(999999);
>>>        return 0;
>>> }
>>> And my init is static build with "-static" option  and I use
>>> cross-objdump to read it and it doesn't tell me there are any library
>>> it depends on.

Are you using a cross-compiler to build your executable ?  If so are you 
sure that you are using the correct cross-compiler for your target 
environment ?

>> I study the kernel source and find my error comes from
>> search_binary_handler and it return -8, -ENOEXEC, while executing,
>> fmt->load_binary.

Which definitely indicates that the kernel does not recognise the file 
format of your executable.  As a matter of interest if you run "file 
<your-executable>"  what does this report ?


>> And I check my fs folder and I only see this *.o files:
>> -rw-r--r-- 1 root root 2748 2009-01-23 11:42 binfmt_script.o
>> which is the default binfmt that will support.

Which looks rather suspicious.  Given that I am not a kernel hacker, so 
the following may well be wrong, but to me that appears to indicate that 
your kernel has been built to only support the execution of shell 
scripts and not any other type of executable file.


>> 1. are my assumptions above correct? take my static build init for
>> example, should I check whether static binary elf support code has
>> build in my kernel?

Yes I think that you should.


>> 2. if my assumption correct, which one in the list is my choice and
>> what config I should add in my uclinxu kernel config?

I would suggest the "elf_format" is the one that you want.

Cheers
   Nick