Re: [Etherboot-developers] Why doesn't gas assemble start32.S

[Marty C. <md...@th...>]

On 2/9/2001 12:36 PM Eno Compton Eno...@Mi... wrote:
>Tried to assemble start32.S. Was amazed to discover errors occur even on
>comment lines. Obviously, some assembler, other than gas, has been used to
>assemble the code.
>Discovered as well, gas includes only one pass, which, among other things,
>makes an assembly listing of questionable value.
>These things suggest to me, real programmers are using an assembler other
>than gas.
>Would somebody please fill me in on these questions?
>How does one assemble start32.S?

Good question.  Let's see how the Makefile does it:

$ grep start32 Makefile
SRCS=   floppyload.S comload.S liloprefix.S loader.S start16.S start32.S 
serial.S
START32=        start32.o.pre
START32=        bin32/start32.o
# To make sure that this actually builds a start32.o.pre with all options 
set,
precompiled:    bin/rloader.bin bin/rzloader.bin bin/prloader.bin 
bin/przloader.bin bin/floppyload.bin bin/comload.bin bin16/start16.o 
bin32/start32.o bin/liloprefix.bin
        cp -p bin32/start32.o start32.o.pre

Well, it seems to be part of the "precompiled" family.  Let's see what 
happens if we do that:

[mdc@rom src]$ make precompiled
gcc -E -DUSE_AS86 -DMOVEROM -DRELOC=0x98000 -o bin/rloader.s loader.S
as86  -0 -b bin/rloader.bin bin/rloader.s
gcc -E -DUSE_AS86 -DMOVEROM -DRELOC=0x98000 -DZLOADER -o bin/rzloader.s 
loader.S
as86  -0 -b bin/rzloader.bin bin/rzloader.s
gcc -E -DUSE_AS86 -DMOVEROM -DRELOC=0x98000 -DPCI_PNP_HEADER -o 
bin/prloader.s loader.S
as86  -0 -b bin/prloader.bin bin/prloader.s
gcc -E -DUSE_AS86 -DMOVEROM -DRELOC=0x98000 -DPCI_PNP_HEADER -DZLOADER -o 
bin/przloader.s loader.S
as86  -0 -b bin/przloader.bin bin/przloader.s
gcc -E -DUSE_AS86 -o bin/floppyload.s floppyload.S
as86  -0 -b bin/floppyload.bin bin/floppyload.s
gcc -E -DUSE_AS86 -o bin/comload.s comload.S
as86  -0 -b bin/comload.bin bin/comload.s
bcc -DMOTD -DIMAGE_MENU -DBACKOFF_LIMIT=7 -DASK_BOOT=3 
-DANS_DEFAULT=ANS_NETWORK -O -ansi  -DVERSION=\"4.6.12\" -DRELOC=0x98000  
-c -o bin16/start16.o start16.S

[here's where start32.S gets assembled]

gcc -E -DMOTD -DIMAGE_MENU -DBACKOFF_LIMIT=7 -DASK_BOOT=3 
-DANS_DEFAULT=ANS_NETWORK -O2 -g -fstrength-reduce -fomit-frame-pointer 
-m386 -malign-jumps=1 -malign-loops=1 -malign-functions=1 -Wall -W 
-Wno-format -Wno-unused -DVERSION=\"4.6.12\" -DRELOC=0x98000  start32.S | 
as  -o bin32/start32.o
{standard input}: Assembler messages:
{standard input}:339: Warning: indirect ljmp without `*'

[the warnings can be safely ignored, I'm told]

gcc -E -DUSE_AS86 -o bin/liloprefix.s liloprefix.S
as86  -0 -b bin/liloprefix.bin bin/liloprefix.s
cp -p bin/rloader.bin rloader.bin.pre
cp -p bin/rzloader.bin rzloader.bin.pre
cp -p bin/prloader.bin prloader.bin.pre
cp -p bin/przloader.bin przloader.bin.pre
cp -p bin/floppyload.bin floppyload.bin.pre
cp -p bin/comload.bin comload.bin.pre
cp -p bin16/start16.o start16.o.pre
cp -p bin32/start32.o start32.o.pre
cp -p bin/liloprefix.bin liloprefix.bin.pre

OK, so it puts it in bin32/start32.o

Let's try making that:

[mdc@rom src]$ make bin32/start32.o
gcc -E -DMOTD -DIMAGE_MENU -DBACKOFF_LIMIT=7 -DASK_BOOT=3 
-DANS_DEFAULT=ANS_NETWORK -O2 -g -fstrength-reduce -fomit-frame-pointer 
-m386 -malign-jumps=1 -malign-loops=1 -malign-functions=1 -Wall -W 
-Wno-format -Wno-unused -DVERSION=\"4.6.12\" -DRELOC=0x98000  start32.S | 
as  -o bin32/start32.o
{standard input}: Assembler messages:
{standard input}:339: Warning: indirect ljmp without `*'

That looks like it.  I guess it needs lots of options to assemble 
properly.

Hope this helps,

Marty


---
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   Name: Martin D. Connor
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