Re: someone make me understand make please

[Martin Knappe]

Thanks! That did the trick. I still don't understand make though; I 
really would like too. Where are these things described? There are a 
couple make tutorials on the net, but as I see it, they all don't go 
beyond very simple things. Then there is this O'Reilly book about make, 
but I'm not sure if it's any good. The make manual is definitely not 
very instructive :-(
Know any good resource?

Thanks again

Martin

Paul Smith wrote:
> On Sun, 2007-08-05 at 21:35 +0100, Martin Knappe wrote:
>   
> > To be honest, I've tried so many combinations of $, `` and stuff that I 
> > just didn't know which of all the version (that didn't work out) I 
> > should have posted :-) They all had different bugs..
> > Yeah, sorry, 512.bin depends on boot.bin, not on boot.bin.bin (typo)
> > Couldnt you just tell me how YOU would write the Makefile to do what I 
> > want so I can see clearer ,please?
> >     
>
> Please reply to the list, not to me privately: if you send it to the
> list others besides me can help, plus other people reading the archives
> can see the entire thread.
>
> This is how I would write it:
>
>         # How we compute the size of the boot file
>         BOOT_SIZE = `stat -c %s boot.bin`
>         
>         512.bin: 512.asm Makefile boot.bin
>                 -rm $@
>                 BOOT_SIZE=$(BOOT_SIZE) nasm -f bin $< -o $@
>         
>         boot.bin: main.o video.o utilities.o Makefile
>                 ld $(filter %.o,$^) -e start -N -M > boot.mem -o $@ --oformat 
> binary -T script
>                 ndisasm -b 32 $@ > boot.ndisasm
>                 size=$(BOOT_SIZE); blocks=`expr $$size / 512`; \
>                         dd if=/dev/null of=gdt.bin seek=`expr $$blocks + 1` 
> count=1
>
> If you know for a fact that your /bin/sh will be POSIX compliant, and
> will grok the POSIX $(...) alternative to ``, then you can simplify
> things a bit:
>
>         # How we compute the size of the boot file
>         BOOT_SIZE = $$(stat -c %s boot.bin)
>         
>         512.bin: 512.asm Makefile boot.bin
>                 -rm $@
>                 BOOT_SIZE=$(BOOT_SIZE) nasm -f bin $< -o $@
>         
>         boot.bin: main.o video.o utilities.o Makefile
>                 ld $(filter %.o,$^) -e start -N -M > boot.mem -o $@ --oformat 
> binary -T script
>                 ndisasm -b 32 $@ > boot.ndisasm
>                 dd if=/dev/null of=gdt.bin seek=$$(expr $$(expr $(BOOT_SIZE) / 
> 512) + 1) count=1
>
> And, if you know that your /bin/sh will be a POSIX shell, and will grok
> the POSIX $(( ... )) math expression, you can do even better:
>
>         # How we compute the size of the boot file
>         BOOT_SIZE = $$(stat -c %s boot.bin)
>         
>         512.bin: 512.asm Makefile boot.bin
>                 -rm $@
>                 BOOT_SIZE=$(BOOT_SIZE) nasm -f bin $< -o $@
>         
>         boot.bin: main.o video.o utilities.o Makefile
>                 ld $(filter %.o,$^) -e start -N -M > boot.mem -o $@ --oformat 
> binary -T script
>                 ndisasm -b 32 $@ > boot.ndisasm
>                 dd if=/dev/null of=gdt.bin seek=$$(( ($(BOOT_SIZE) / 512) + 1 
> )) count=1
>
>