RE: problem mounting ramdisk

RE: problem mounting ramdisk

[Jim Lewis]

Hi,
It looks to me like you made your ramdisk bigger than 4MB, which is
the default ramdisk size. You can either modify drivers/block/rd.c and
change the value of rd_size, add the "ramdisk_size=" parm to the boot
command line, or create a smaller ramdisk image.
-Jim Lewis

> -----Original Message-----
> From: owner-linuxppc-embedded@lists.linuxppc.org
> [mailto:owner-linuxppc-embedded@lists.linuxppc.org]On
> Behalf Of Andreas
> Schreckenberg
> Sent: Thursday, January 04, 2001 12:50 PM
> To: linuxppc-embedded@lists.linuxppc.org
> Subject: problem mounting ramdisk
>
>
>
> hello,
>
> My linux (modified kernel 2.2.14) starts
> on my custom PPC board (PPC750/128MB)
> but when I mount the ramdisk, the kernel issues:
>
> ...
> Serial driver version 4.27 with no serial options enabled
> ttyS00 at 0x12000000 (irq = 16) is a 16550A
> RAM disk driver initialized:  16 RAM disks of 4096K size
> RAMDISK: Compressed image found at block 0
> attempt to access beyond end of device
> 01:00: rw=0, want=8196, limit=4096
> dev 01:00 blksize=1024 blocknr=8195 sector=16390 size=1024 count=1
> EXT2-fs error (device ramdisk(1,0)): read_block_bitmap:
> Cannot read block bitmap - block_group = 1, block_bitmap = 52428800
> attempt to access beyond end of device
> 01:00: rw=0, want=16386, limit=4096
> dev 01:00 blksize=1024 blocknr=16385 sector=32770 size=1024 count=1
> EXT2-fs error (device ramdisk(1,0)): read_block_bitmap:
> Cannot read block bitmap - block_group = 2, block_bitmap = 20971520
> attempt to access beyond end of device
> 01:00: rw=0, want=24580, limit=4096
> ... (and so on)
>
> ... (later)
> VFS: Mounted root (ext2 filesystem).
> Freeing unused kernel memory: 40k init 28k prep 4k pmac 12k
> open firmware
> ...
>
> ... (last)
> EXT2-fs error (device ramdisk(1,0)): ext2_read_inode:
> unable to read inode block - inode=4001, block=16389
> Kernel panic: No init found.  Try passing init= option to kernel.
> Rebooting in 5 seconds..
> ...
>
> The fs image contains no shell at the moment, so the last
> kernel panic is okay.
>
> What is the Problem with EXT2-fs error ?
> I used the following script on my x86 host (<- the problem ?)
> to build the compressed image:
>
> #!/bin/sh
> dd if=/dev/zero of=/dev/ram bs=1k count=4096
> mke2fs -m0 /dev/ram
> mkdir -p /mnt/ram
> mount /dev/ram /mnt/ram
> (cd file_system; cp -a * /mnt/ram)
> umount /mnt/ram
> rmdir /mnt/ram
> dd if=/dev/ram of=fs_images/ramdisk.image bs=1k count=4096
> (cd fs_images;gzip -v9f ramdisk.image)
>
> every help would be appreciated...
>
> bye
> Andreas
> --
>           Life's not fair. But the root password helps ! :-)
>                    http://schrecky.home.pages.de
>


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

problem mounting ramdisk

[Andreas Schreckenberg]

hello,

My linux (modified kernel 2.2.14) starts
on my custom PPC board (PPC750/128MB)
but when I mount the ramdisk, the kernel issues:

...
Serial driver version 4.27 with no serial options enabled
ttyS00 at 0x12000000 (irq = 16) is a 16550A
RAM disk driver initialized:  16 RAM disks of 4096K size
RAMDISK: Compressed image found at block 0
attempt to access beyond end of device
01:00: rw=0, want=8196, limit=4096
dev 01:00 blksize=1024 blocknr=8195 sector=16390 size=1024 count=1
EXT2-fs error (device ramdisk(1,0)): read_block_bitmap: Cannot read block bitmap - block_group = 1, block_bitmap = 52428800
attempt to access beyond end of device
01:00: rw=0, want=16386, limit=4096
dev 01:00 blksize=1024 blocknr=16385 sector=32770 size=1024 count=1
EXT2-fs error (device ramdisk(1,0)): read_block_bitmap: Cannot read block bitmap - block_group = 2, block_bitmap = 20971520
attempt to access beyond end of device
01:00: rw=0, want=24580, limit=4096
... (and so on)

... (later)
VFS: Mounted root (ext2 filesystem).
Freeing unused kernel memory: 40k init 28k prep 4k pmac 12k open firmware
...

... (last)
EXT2-fs error (device ramdisk(1,0)): ext2_read_inode: unable to read inode block - inode=4001, block=16389
Kernel panic: No init found.  Try passing init= option to kernel.
Rebooting in 5 seconds..
...

The fs image contains no shell at the moment, so the last kernel panic is okay.

What is the Problem with EXT2-fs error ?
I used the following script on my x86 host (<- the problem ?)
to build the compressed image:

#!/bin/sh
dd if=/dev/zero of=/dev/ram bs=1k count=4096
mke2fs -m0 /dev/ram
mkdir -p /mnt/ram
mount /dev/ram /mnt/ram
(cd file_system; cp -a * /mnt/ram)
umount /mnt/ram
rmdir /mnt/ram
dd if=/dev/ram of=fs_images/ramdisk.image bs=1k count=4096
(cd fs_images;gzip -v9f ramdisk.image)

every help would be appreciated...

bye
Andreas
--
          Life's not fair. But the root password helps ! :-)
                   http://schrecky.home.pages.de

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: problem mounting ramdisk

[Tania Oka]

I had a similar problem (with the "attempt to access beyond end of device" symptom) when the size of my initrd exceeded the
kernel ramdisk_size.  I don't see the problem with your script but I used a slightly different method so I am including the
script which eventually worked for me (on an x86 host, by the way).  Might be worth a try.  You also might try increasing the
kernel's idea of the ramdisk size to see if it helps (one way is to edit ramroot_string in arch/ppc/boot/misc.c, I use
"root=/dev/ram ramdisk_size=6144").

Here's my script:

# NOTE: (bs * count) <= ramdisk_size
# the ramdisk uncompress/init code will NOT complain if you exceed ramdisk_size,
# but you may see "attempt to access beyond end of device" messages
dd if=/dev/zero of=/tmp/ramimage.tmp bs=1k count=4096
/sbin/mke2fs -m 0 -i 2000 /tmp/ramimage.tmp
mount -o loop -t ext2 /tmp/ramimage.tmp /mnt
cd file_system; tar cf - * | (cd /mnt; tar xf -)
umount /mnt
dd if=/tmp/ramimage.tmp bs=1k | gzip -v9 > ramdisk.gz
du -ch file_system > file_system.txt

The last line is just for informational purposes.

Good luck.
Tania


Andreas Schreckenberg wrote:

> hello,
>
> My linux (modified kernel 2.2.14) starts
> on my custom PPC board (PPC750/128MB)
> but when I mount the ramdisk, the kernel issues:
>
> ...
> Serial driver version 4.27 with no serial options enabled
> ttyS00 at 0x12000000 (irq = 16) is a 16550A
> RAM disk driver initialized:  16 RAM disks of 4096K size
> RAMDISK: Compressed image found at block 0
> attempt to access beyond end of device
> 01:00: rw=0, want=8196, limit=4096
> dev 01:00 blksize=1024 blocknr=8195 sector=16390 size=1024 count=1
> EXT2-fs error (device ramdisk(1,0)): read_block_bitmap: Cannot read block bitmap - block_group = 1, block_bitmap = 52428800
> attempt to access beyond end of device
> 01:00: rw=0, want=16386, limit=4096
> dev 01:00 blksize=1024 blocknr=16385 sector=32770 size=1024 count=1
> EXT2-fs error (device ramdisk(1,0)): read_block_bitmap: Cannot read block bitmap - block_group = 2, block_bitmap = 20971520
> attempt to access beyond end of device
> 01:00: rw=0, want=24580, limit=4096
> ... (and so on)
>
> ... (later)
> VFS: Mounted root (ext2 filesystem).
> Freeing unused kernel memory: 40k init 28k prep 4k pmac 12k open firmware
> ...
>
> ... (last)
> EXT2-fs error (device ramdisk(1,0)): ext2_read_inode: unable to read inode block - inode=4001, block=16389
> Kernel panic: No init found.  Try passing init= option to kernel.
> Rebooting in 5 seconds..
> ...
>
> The fs image contains no shell at the moment, so the last kernel panic is okay.
>
> What is the Problem with EXT2-fs error ?
> I used the following script on my x86 host (<- the problem ?)
> to build the compressed image:
>
> #!/bin/sh
> dd if=/dev/zero of=/dev/ram bs=1k count=4096
> mke2fs -m0 /dev/ram
> mkdir -p /mnt/ram
> mount /dev/ram /mnt/ram
> (cd file_system; cp -a * /mnt/ram)
> umount /mnt/ram
> rmdir /mnt/ram
> dd if=/dev/ram of=fs_images/ramdisk.image bs=1k count=4096
> (cd fs_images;gzip -v9f ramdisk.image)
>
> every help would be appreciated...
>
> bye
> Andreas
> --
>           Life's not fair. But the root password helps ! :-)
>                    http://schrecky.home.pages.de
>


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: problem mounting ramdisk

[Andreas Schreckenberg]

Tania Oka wrote:
>

Hello,

> I had a similar problem (with the "attempt to access beyond end of device" symptom)
> when the size of my initrd exceeded the ...

Thanks a lot. Yes indeed the problem was the ramdisk size.

#!/bin/sh
dd if=/dev/zero of=/dev/ram bs=1k count=4096
mke2fs -m0 /dev/ram

I changed Line 3 (give mke2fs the right number of blocks):
mke2fs -vm0 /dev/ram 4096 and add the line ramdisk_size=4096 to the kernel.

...
RAM disk driver initialized:  16 RAM disks of 4096K size
RAMDISK: Compressed image found at block 0
VFS: Mounted root (ext2 filesystem).
Freeing unused kernel memory: 36k init 28k prep 4k pmac 12k open firmware
...

Vola. The ramdisk starts.

But my sash do not come up.
The kernel hangs without panic issues.

I used in /bin (the sash seems to be a little big):
-rwxr-xr-x   1 root     root       467284 Jan  5 11:32 sash
lrwxrwxrwx   1 root     root            4 Jan  5 17:19 sh -> sash

from:
hhl-ppc_7xx-sash-3.4-5.noarch.rpm  (alien -t because I use debian)
                         ^ ??? (the problem)
-> hhl-ppc_7xx-sash-3.4.tgz
(from the Monta Vista Hardhat /pub/CDK/1.2/latest/PowerPC/ppc_7xx/RPMS)

I compiled the kernel with CONFIG_BINFMT_ELF without CONFIG_SASH.
Do I need CONFIG_BINFMT_ELF32 or CONFIG_SASH ? What the difference ?

When I try to cross compile the sash:
...
powerpc-linux-gcc -static -s -o sash sash.o cmds.o cmd_dd.o cmd_ed.o cmd_grep.o cmd_ls.o cmd_tar.o cmd_gzip.o cmd_find.o
cmd_file.o cmd_chattr.o cmd_ar.o utils.o
/usr/local/powerpc-linux/bin/ld: cannot open crt1.o: No such file or directory
collect2: ld returned 1 exit status
make: *** [sash] Error 1
...

crt1.o = "c run time environment"

What's my problem ? I'm a bloody newbie to linux kernel/cross development :-)
Hope I am not offtopic here.

I installed gcc-2.95.2 and binutils-2.9.5.0.22 on my host described in
http://members.nbci.com/greyhams/linux/PowerPC-Embedded-HOWTO.html
(enough to build the kernel)

Is there anybody who can give me a valid ramdisk_image for a PPC750 System.
I need: cat,ls,insmod,bash and sash
(the ramdisk should be not greater then 16M)
Write to: ASchreckenberg@dspace.de

Any help would be welcome...

bye
Andreas
--
          Life's not fair. But the root password helps ! :-)
                   http://schrecky.home.pages.de

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/