Re: Linux hanging on Xilinx SystemACE

[Jeff Angielski <jangiels@speakeasy.net>]

On Wed, 2006-08-16 at 15:48 -0600, Grant Likely wrote:
> On 8/16/06, Clint Thomas <cthomas@soneticom.com> wrote:
> >
> >
> > Hey,
> >
> > Using the powerpc development tree of Linux 2.4, I am trying to boot my
> > system from CompactFlash using Xilinx SystemACE. My compact flash card has
> > two partitions, a 16MB FAT16 that holds the combination FPGA image / Linux
> > Kernel ELF file, and an Ext2 partition that holds the root file system. The
> > system starts the boot process, uncompresses the Linux kernel and begins
> > loading drivers. Part way into this process, it conducts a partition check
> > of the drive being reported to it by SystemACE, however, it hangs at that
> > point. No kernel panic, no error message, it simply hangs. Here is the
> > output at that point...
> >
> > Partition check:
> >  xsysacea:
> >
> > what I am trying to find out is if this problem has been seen/fixed in the
> > past? or did I format the CF card incorrectly?

I forgot to mention that we used to see this problem when the identify
command that is sent during intialization fails.  The driver is written
in such a way that if any of this fails, the system hangs because it
sits in a polling loop waiting for the correct response.  There are no
timeout failures... :(  In our case we saw this error because we forgot
to put a CF into the system [usually during development with NFS
rootfs].

It is fairly easy to printk() the drivers init code to find out which
step is stuck in the polling loop.

> Checking partitions is a user-space activity (fsck).  Remove it from
> your init scripts.  Besides, unless your using a microdrive, your ext2
> rootfs should be mounted read-only which greatly reduces the need for
> fsck.  (because FLASH will wear out after too many writes)

The partition check he is referring to is part of a block device driver
initialization.  It is not fsck.  If he were only so luck to be that far
in the startup sequence... :)



Jeff Angielski
The PTR Group