ram root filesystem

ram root filesystem

[AlessandroPPC]

Hi to all,

I'm developing a custom application on 8260 based board. I have first used
the ELDK package version 2.0.2 with Kernel 2.4.4
and nfs root filesystem. Now I want migrate my application on the system
using ram fs instead of nfs.
To do this I have generated a ramdisk image derived from ELDK fs eliminating
superfluous packages and using a makefile with
this instructions:

 @echo "********************************************"
 @echo "create root files system"
 @echo "********************************************"
 rm -rf $(BUILD)/var/log/tegated
 mkdir $(BUILD)/var/log/tegated
 rm -rf $(RAMFS)/tmp/
 mkdir $(RAMFS)/tmp
 dd if=/dev/zero of=$(RAMFS)/ramrootfs bs=1k count=36864
 mke2fs -F -m0 $(RAMFS)/ramrootfs
 mount -o loop -t ext2 $(RAMFS)/ramrootfs $(RAMFS)/tmp
 cp -av $(BUILD)/* $(RAMFS)/tmp
 umount $(RAMFS)/tmp
 cat $(RAMFS)/ramrootfs | gzip -9 > $(IMGTGZ)
 /opt/eldk/usr/bin/mkimage -T ramdisk -C gzip -n "DexGate filesystem
image" -d $(IMGTGZ) $(RAMDSK)
 rm -rf $(RAMFS)/tmp/
 @echo "********************************************"
 @echo "Ramdisk image now in /tftpboot/ramdisk"
 @echo "********************************************"


In this way I'm able obtain a valid ramdisk image to download on my board
using ppcboot. giving the commands

bootp 0x2500000 /tftpboot/image
BOOTP broadcast 1
ARP broadcast 1
TFTP from server 10.0.0.4; our IP address is 10.0.0.20
Filename '/tftpboot/image'.
Load address: 0x2500000
Loading: #################################################################
         #######################################################
done
Bytes transferred = 610742 (951b6 hex)
fec001> bootp 0x2600000 /tftpboot/ramdisk
BOOTP broadcast 1
ARP broadcast 2
TFTP from server 10.0.0.4; our IP address is 10.0.0.20
Filename '/tftpboot/ramdisk'.
Load address: 0x2600000
Loading: #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
done
Bytes transferred = 11645509 (b1b245 hex)
fec001> setenv bootargs root=/dev/ram rw
fec001> bootm 0x2500000 0x2600000

At this point the system boots and the kernel mounts the ram disk but at
time of rc.sysint script I have this error :

VFS: Mounted root (ext2 filesystem).
Freeing unused kernel memory: 60k init
INIT: version 2.78 booting

Mounting proc filesystem                   :  [  OK  ]
Configuring kernel parameters              :  [  OK  ]
Setting clock : Wed Dec 31 19:00:15 EST 1969  [  OK  ]
Activating swap partitions                 :  [  OK  ]
Setting hostname 10.0.0.20                 :  [  OK  ]
Checking root filesystem
/dev/ram:
The superblock could not be read or does not describe a correct ext2
filesystem.  If the device is valid and it really contains an ext2
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
    e2fsck -b 8193 <device>

[/sbin/fsck.ext2 (1) -- /] fsck.ext2 -a /dev/ram
fsck.ext2: Bad magic number in super-block while trying to open /dev/ram
[FAILED]

*** An error occurred during the file system check.
*** Dropping you to a shell; the system will reboot
*** when you leave the shell.
Give root password for maintenance
(or type Control-D for normal startup):


Notice that if  I write  rc.sysinit script to skip "Checking root
filesystem" I obtain the prompt but the syslogd deamon fails the startup.

>From ELDK distribution I have changed /etc/fstab file in

/dev/ram                /               ext2    defaults       0 0
none                    /proc           proc    defaults       0 0

and /etc/mtab file in

/dev/ram / ext2 rw 0 0
none /proc proc rw 0 0

Someone can say why fsck is not able to check ram fs and if the syslogd
problem is related to ram fs?

thanks to all,
Regards,
Alessandro.


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Re: ram root filesystem

[Wolfgang Denk]

Dear Alessandro,

in message <019501c3b9c5$b339a060$0400a8c0@eurostudio.local> you wrote:
>
> To do this I have generated a ramdisk image derived from ELDK fs eliminating
> superfluous packages and using a makefile with

Question 1: why don't you use the  much  simpler  and  smaller  setup
based  on  the  SELF  ramdisk  example  image included with the ELDK?
Please see http://www.denx.de/twiki/bin/view/DULG/HowToAddFiles

>  dd if=/dev/zero of=$(RAMFS)/ramrootfs bs=1k count=36864
>  mke2fs -F -m0 $(RAMFS)/ramrootfs
>  mount -o loop -t ext2 $(RAMFS)/ramrootfs $(RAMFS)/tmp

Question 2: Why don't you simply use the genext2fs  tool  that  comes
included  with  the  ELDK?  It  is much simpler, and requires no root
permissions to create a ramdisk image.

> At this point the system boots and the kernel mounts the ram disk but at
> time of rc.sysint script I have this error :
...
> Notice that if  I write  rc.sysinit script to skip "Checking root
> filesystem" I obtain the prompt but the syslogd deamon fails the startup.

The "rc.sysint" was never meant to be used from a ramdisk based  root
filesystem.  If  you  change  your configuration, you are expected to
adapt all related config files and init scripts, too.

> Someone can say why fsck is not able to check ram fs and if the syslogd
> problem is related to ram fs?

It makes no sense to run fsck on  a  ramdisk  image  which  was  just
unpacked.  Also,  IMHO  it  makes littlee sense to use the full-blown
SysV init style scripts in an embedded system which is running from a
ramdisk image.

Have a look at the ELF image thatis included with the ELDK,  and  use
this as a base.

Best regards,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
When all is said and done, more is said than done.

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problem using both mpc857dsl fec and scc1

[Dennis Khoo]

Hi all,

I'm having a peculiar problem.

Briefly, my platform is MPC857DSL IAD board from Motorola.  I'm using U-boot
0.4.8 to bootp the kernel(2.4.18 and 2.4.22)  through SCC1 and then load
NFS.   If I configure the kernel with only SCC1, then everything works
well(NFS works and ping through eth0 works).  If I configure the kernel with
only FEC (in fec.c PDPAR[UT]=0,UTMOD[SPLIT]=1,ENCTRL[FEC_PIN_MUX]=1), then
everything works well through FEC which is hooked up to a RealTek RTL8305S
switch.

But if I configure the kernel to use both SCC1 and FEC, SCC1 works and FEC
doesn't.  NFS and ping run well through SCC1(eth0).  But when I try to ping
out through FEC(eth1), I get ring buffer dumps and no ping response:

NETDEV WATCHDOG: eth1: transmit timed out
eth1: transmit timed out.
Ring data dump: cur_tx c1fa8100, tx_free 0, dirty_tx c1fa8100, cur_rx
c1fa8020
 tx: 16 buffers
  c1fa8100: 9c00 002a 01f868c2
  c1fa8108: 9c00 002a 01f86842
  c1fa8110: 9c00 002a 01f867c2
  c1fa8118: 9c00 002a 01f86742
  c1fa8120: 9c00 002a 01f866c2
  c1fa8128: 9c00 002a 01f86642
  c1fa8130: 9c00 002a 01f865c2
  c1fa8138: 9c00 002a 01f86542
  c1fa8140: 9c00 002a 01f864c2
  c1fa8148: 9c00 002a 01f86442
  c1fa8150: 9c00 002a 01f863c2
  c1fa8158: 9c00 002a 01f86342
  c1fa8160: 9c00 002a 01f862c2
  c1fa8168: 9c00 002a 01dafbe2
  c1fa8170: 9c00 002a 01dafb62
  c1fa8178: bc00 002a 01dafce2
 rx: 32 buffers
  c1fa8000: 8880 0252 01fa7000
  c1fa8008: 8880 0040 01fa7800
  c1fa8010: 8880 0162 01fa6000
  c1fa8018: 8880 0040 01fa6800
  c1fa8020: 8000 0000 01fa5000
  c1fa8028: 8000 0000 01fa5800
  c1fa8030: 8000 0000 01fa4000
  c1fa8038: 8000 0000 01fa4800
  c1fa8040: 8000 0000 01fa3000
  c1fa8048: 8000 0000 01fa3800
  c1fa8050: 8000 0000 01fa2000
  c1fa8058: 8000 0000 01fa2800
  c1fa8060: 8000 0000 01fa1000
  c1fa8068: 8000 0000 01fa1800
  c1fa8070: 8000 0000 01fa0000
  c1fa8078: 8000 0000 01fa0800
  c1fa8080: 8000 0000 01f9f000
  c1fa8088: 8000 0000 01f9f800
  c1fa8090: 8000 0000 01f9e000
  c1fa8098: 8000 0000 01f9e800
  c1fa80a0: 8000 0000 01f9d000
  c1fa80a8: 8000 0000 01f9d800
  c1fa80b0: 8000 0000 01f9c000
  c1fa80b8: 8000 0000 01f9c800
  c1fa80c0: 8000 0000 01f9b000
  c1fa80c8: 8000 0000 01f9b800
  c1fa80d0: 8000 0000 01f9a000
  c1fa80d8: 8000 0000 01f9a800
  c1fa80e0: 8000 0000 01f99000
  c1fa80e8: 8000 0000 01f99800
  c1fa80f0: 8000 0000 01f98000
  c1fa80f8: a000 0000 01f98800


Doing an ifconfig gives me......(TX errors continue to accumulate
indefinitely even after I stop ping)

eth0      Link encap:Ethernet  HWaddr 00:02:87:55:66:77
          inet addr:199.199.199.129  Bcast:199.199.199.255
Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1538 errors:0 dropped:0 overruns:0 frame:0
          TX packets:698 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:1787601 (1.7 Mb)  TX bytes:102816 (100.4 kb)
          Base address:0x3c00

eth1      Link encap:Ethernet  HWaddr 00:02:87:D5:66:77
          inet addr:192.168.2.129  Bcast:192.168.2.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:4 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:5 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:1076 (1.0 kb)  TX bytes:672 (672.0 b)
          Base address:0xe00

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:21 errors:0 dropped:0 overruns:0 frame:0
          TX packets:21 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:2352 (2.2 kb)  TX bytes:2352 (2.2 kb)


Any help is deeply appreciated.

Thanks,
Dennis Khoo
Software Engineer
Adapcom, INC.


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Use of several CFI flash chips physically mapped in memory

[Gérard Guével]

Hi,

I work on a custom 8250 board with a 2.4.18 Linux kernel.
This board provides two AMD CFI flash devices.

Nowaday I only use the first chip which I map in the physical memory.
I create several partitions with RW or RO accesses and I use
CRAMFS and/or JFFS2 images. This works fine.

Now I would want to use the following functionalities :

1) I want to protect the first partition of the first device
that contains a firmware which does not belong to the Linux system.
Can I mislead Linux and provide the first sector address after
the firware as the start address of the device. I don't know
how the gen_probe process will react. So as Linux does not know
the firware space and it can't erase the firmware sectors.

2) I want to use the two devices as a virtual one with many
partitions splitted at will. The two chips are physically mapped in
sequence. In my kernel, I have the following variables
CONFIG_ELINOS_NR_MTD_DEVICES "Maximum number of MTD devices" and
CONFIG_MTD_CONCAT MTD "Concatenating support". But they seem to be unused.

3) I want to use two 16 bits access chips physically mounted in parallel
to make a virtual 32 bits access chip. Do solutions exist for this case ?

4) Finally, what about flash fast programming issues ?
Nowaday it is very slow to erase or program many sectors with
the character access driver.
In my kernel, I have the following message
if (cfi->fast_prog) {
    /* In cfi_amdstd_write() we frob the protection stuff
       without paying any attention to the state machine.
       This upsets in-progress erases. So we turn this flag
       off for now till the code gets fixed. */
    printk(KERN_NOTICE "cfi_cmdset_0002: Disabling fast programming due to c
ode brokenness.\n");
    cfi->fast_prog = 0;
}

Thanks
Special thanks to Gary Thomas for his reply about File system boot strategy.


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R: ram root filesystem

[AlessandroPPC]

Many Thanks Wolfgang Denk for your indacations.
Something abaut your questions.

> Question 1: why don't you use the  much  simpler  and  smaller  setup
> based  on  the  SELF  ramdisk  example  image included with the ELDK?
> Please see http://www.denx.de/twiki/bin/view/DULG/HowToAddFiles

My application now is running and it is stable with nfs-ELDK package, and I
want pass
to ram fs to do a more efficiently embedded system with the minimum
difference respect
 to nfs because I don't want to lose the stability.

> Question 2: Why don't you simply use the genext2fs  tool  that  comes
> included  with  the  ELDK?  It  is much simpler, and requires no root
> permissions to create a ramdisk image.
>

Yes I will try the genext2fs  tool .

> The "rc.sysint" was never meant to be used from a ramdisk based  root
> filesystem.  If  you  change  your configuration, you are expected to
> adapt all related config files and init scripts, too.

Ok I 'm just adapting my config files and init scripts.


>
> It makes no sense to run fsck on  a  ramdisk  image  which  was  just
> unpacked.  Also,  IMHO  it  makes littlee sense to use the full-blown
> SysV init style scripts in an embedded system which is running from a
> ramdisk image.
>
Yes I agree, but the question is : why a tool thought to check fs don't work
on my fs image? Where is the mistake?
Sorry, but what do yo mean with IMHO ?

> Have a look at the ELF image thatis included with the ELDK,  and  use
> this as a base.
>
I'm investigating abaut your ELF image...

Thanks again,
Regards,
Alessandro


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Re: problem using both mpc857dsl fec and scc1

[Jaap-Jan Boor]

Hi,

I would say to double check your parallel port I/O settings

Jaap-Jan

On Thu, 2003-12-04 at 01:08, Dennis Khoo wrote:
> Hi all,
>
> I'm having a peculiar problem.
>
> Briefly, my platform is MPC857DSL IAD board from Motorola.  I'm using U-boot
> 0.4.8 to bootp the kernel(2.4.18 and 2.4.22)  through SCC1 and then load
> NFS.   If I configure the kernel with only SCC1, then everything works
> well(NFS works and ping through eth0 works).  If I configure the kernel with
> only FEC (in fec.c PDPAR[UT]=0,UTMOD[SPLIT]=1,ENCTRL[FEC_PIN_MUX]=1), then
> everything works well through FEC which is hooked up to a RealTek RTL8305S
> switch.
>
> But if I configure the kernel to use both SCC1 and FEC, SCC1 works and FEC
> doesn't.  NFS and ping run well through SCC1(eth0).  But when I try to ping
> out through FEC(eth1), I get ring buffer dumps and no ping response:
>
> NETDEV WATCHDOG: eth1: transmit timed out
> eth1: transmit timed out.
> Ring data dump: cur_tx c1fa8100, tx_free 0, dirty_tx c1fa8100, cur_rx
> c1fa8020
>  tx: 16 buffers
>   c1fa8100: 9c00 002a 01f868c2
>   c1fa8108: 9c00 002a 01f86842
>   c1fa8110: 9c00 002a 01f867c2
>   c1fa8118: 9c00 002a 01f86742
>   c1fa8120: 9c00 002a 01f866c2
>   c1fa8128: 9c00 002a 01f86642
>   c1fa8130: 9c00 002a 01f865c2
>   c1fa8138: 9c00 002a 01f86542
>   c1fa8140: 9c00 002a 01f864c2
>   c1fa8148: 9c00 002a 01f86442
>   c1fa8150: 9c00 002a 01f863c2
>   c1fa8158: 9c00 002a 01f86342
>   c1fa8160: 9c00 002a 01f862c2
>   c1fa8168: 9c00 002a 01dafbe2
>   c1fa8170: 9c00 002a 01dafb62
>   c1fa8178: bc00 002a 01dafce2
>  rx: 32 buffers
>   c1fa8000: 8880 0252 01fa7000
>   c1fa8008: 8880 0040 01fa7800
>   c1fa8010: 8880 0162 01fa6000
>   c1fa8018: 8880 0040 01fa6800
>   c1fa8020: 8000 0000 01fa5000
>   c1fa8028: 8000 0000 01fa5800
>   c1fa8030: 8000 0000 01fa4000
>   c1fa8038: 8000 0000 01fa4800
>   c1fa8040: 8000 0000 01fa3000
>   c1fa8048: 8000 0000 01fa3800
>   c1fa8050: 8000 0000 01fa2000
>   c1fa8058: 8000 0000 01fa2800
>   c1fa8060: 8000 0000 01fa1000
>   c1fa8068: 8000 0000 01fa1800
>   c1fa8070: 8000 0000 01fa0000
>   c1fa8078: 8000 0000 01fa0800
>   c1fa8080: 8000 0000 01f9f000
>   c1fa8088: 8000 0000 01f9f800
>   c1fa8090: 8000 0000 01f9e000
>   c1fa8098: 8000 0000 01f9e800
>   c1fa80a0: 8000 0000 01f9d000
>   c1fa80a8: 8000 0000 01f9d800
>   c1fa80b0: 8000 0000 01f9c000
>   c1fa80b8: 8000 0000 01f9c800
>   c1fa80c0: 8000 0000 01f9b000
>   c1fa80c8: 8000 0000 01f9b800
>   c1fa80d0: 8000 0000 01f9a000
>   c1fa80d8: 8000 0000 01f9a800
>   c1fa80e0: 8000 0000 01f99000
>   c1fa80e8: 8000 0000 01f99800
>   c1fa80f0: 8000 0000 01f98000
>   c1fa80f8: a000 0000 01f98800
>
>
> Doing an ifconfig gives me......(TX errors continue to accumulate
> indefinitely even after I stop ping)
>
> eth0      Link encap:Ethernet  HWaddr 00:02:87:55:66:77
>           inet addr:199.199.199.129  Bcast:199.199.199.255
> Mask:255.255.255.0
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:1538 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:698 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:100
>           RX bytes:1787601 (1.7 Mb)  TX bytes:102816 (100.4 kb)
>           Base address:0x3c00
>
> eth1      Link encap:Ethernet  HWaddr 00:02:87:D5:66:77
>           inet addr:192.168.2.129  Bcast:192.168.2.255  Mask:255.255.255.0
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:4 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:0 errors:5 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:100
>           RX bytes:1076 (1.0 kb)  TX bytes:672 (672.0 b)
>           Base address:0xe00
>
> lo        Link encap:Local Loopback
>           inet addr:127.0.0.1  Mask:255.0.0.0
>           UP LOOPBACK RUNNING  MTU:16436  Metric:1
>           RX packets:21 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:21 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:0
>           RX bytes:2352 (2.2 kb)  TX bytes:2352 (2.2 kb)
>
>
> Any help is deeply appreciated.
>
> Thanks,
> Dennis Khoo
> Software Engineer
> Adapcom, INC.
>
>


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Re: problem using both mpc857dsl fec and scc1

[Dennis Khoo]

Hi Jaap-Jan,

> I would say to double check your parallel port I/O settings

Thanks

Actually, when I switched to ramdisk instead of NFS, then both SCC1 and FEC
work together.   Maybe some timimg issue in the fec.c code affected by
packets coming in initially?

Thanks again

Dennis Khoo
Software Engineer
Adapcom, INC


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