Re: How can I use grub_getcrc32 in fs module

[Jiro SEKIBA <jir@unicus.jp>]

Hi,

At Wed, 10 Mar 2010 14:05:25 +0100,
Vladimir 'φ-coder/phcoder' Serbinenko wrote:
> 
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> Jiro SEKIBA wrote:
> > Hi,
> >
> > How can I write Makefile to use grub_getcrc32 in file module?
> >
> > I'm trying to use grub_getcrc32 function to calculate crc of
> > the specific part of the disk so as to validate the disk.
> >   
> Filesystem modules are often size-constrained. So we skip the
> consistency checks unless they are inherent part of filesystem operation.
> If filesystem is corrupted there isn't much we can do other than hope
> that boot-related files aren't affected. GRUB itself never writes to fs
> metadata so it won't lead to any additional corruption

Ah, I see.  Ok, then we may skip checking super block crc.
However, becuase of nature of nilfs2, a log file system,
I need to roll forward the logs to find the latest log
in case that super block does not point appropriate latest log
on unclean unmounting.

In the forwarding process, log is verified by crc.

> > I added lib/crc.c in SOURCES in common.rmk for the fs module.
> > It looks OK to compile the target fs module.
> > However I got following link error for grub-setup and grub-probe.
> >
> > grub_setup-fs_nilfs2.o: In function `grub_nilfs2_valid_sb':
> > nilfs2.c:(.text+0xe29): undefined reference to `grub_getcrc32'
> > nilfs2.c:(.text+0xe47): undefined reference to `grub_getcrc32'
> > nilfs2.c:(.text+0xe7e): undefined reference to `grub_getcrc32'
> > collect2: ld returned 1 exit status
> >
> > I was trying to specify lib/crc.c in grub_setup_SOURCES, but got same result.
> >
> >   
> Stupid question: have you rerun ./autogen.sh ?

Yes, I did.  I should have mentioned.
What I did is

sh autogen.sh
make clean;./configure;make

> > What is the best way to add dependency for those programs if
> > I want to use crc calculation in fs module?
> >
> > thank you very much in advance
> >   
> 
> 
> -- 
> Regards
> Vladimir 'φ-coder/phcoder' Serbinenko
> 
> 
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-- 
Jiro SEKIBA <jir@unicus.jp>