On Fri, Jun 10, 2016 at 01:42:45PM +0200, Edward Bartolo wrote:
> Hi,
>
> While dissecting the sysvinits (/sbin/init) internals I found that gcc
> can link garbage into an executable file. Attempting to run the
> resultant garbage results in unknown executable format or something
> similar.
>
> I used the -c directive directly on the source code. The command is this:
> gcc -ansi -O2 -W -Wall -D_GNU_SOURCE -c startos.init.c -o startos.init
>

It is not gcc "linking garbage into an executable file". With the
command above you are not *linking* anything. You are just compiling
your .c into a relocatable .o "object file", which contains only the
machine code of your program, and nothing else. In orer to transform
it to an executable, you should then link it "with some more
stuff(tm)", e.g. by using ld.

Anyway, the easiest way to obtain an executable is by letting gcc do
the linking, at least in this *basic* case. If you just get rid of the
"-c" and let gcc handle the rest, you will end up having a proper
executable file into "startos.init".

HND

KatolaZ

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[ ~.,_  Enzo Nicosia aka KatolaZ - GLUGCT -- Freaknet Medialab  ]  
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