Date:	Wed, 14 Mar 2001 13:14:15 +0200 (IST)
From:	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender:	eliz AT is
To:	djgpp AT delorie DOT com
Subject:	Re: Linking to binary format
In-Reply-To:	<984559248.3aaf2e90465a3@webmail.cotse.com>
Message-ID:	<Pine.SUN.3.91.1010314130246.24012A-100000@is>
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Reply-To:	djgpp AT delorie DOT com
Errors-To:	nobody AT delorie DOT com
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On Wed, 14 Mar 2001 wmitty-no-spam AT cotse DOT com wrote:

> then try to link it as a pure binary file (so my bootloader can load it) as
> follows
> 
> ld mytest.o -o mytest.bin -oformat binary -Ttext 0x100000 -lc
> 
> but this produces the error:
> 
> warning: cannot find entry symbol start; defaulting to 00100000

This is self-explaining, no?  The linker says that you didn't tell it 
the address of the program's entry point.  (The "-Ttext 0x100000" defines 
the starting address of the .text section, but doesn't say where's the 
first instruction to be executed when the program starts.)

> followed by many errors such as:
> 
> d:/djgpp/bin/../lib/libc.a(doprnt.o)(.text+0xafd):doprnt.c: undefined
> reference to '___umoddi3'
> d:/djgpp/bin/../lib/libc.a(doprnt.o)(.text+0xb3c):doprnt.c: undefined
> reference to '___udivdi3'

That's because you didn't link against libgcc.a, which defines these 
functions.  You should use "-lgcc -lc -lgcc" at the end of the link 
command, instead of just "-lc".

(You might try linking a normal DJGPP program via "gcc -v", to make the 
compiler print the command line it uses to invoke the linker: then you 
will see all the magic options it passes to the linker to make it DTRT.)

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