[U-Boot-Users] Quick booting

[U-Boot-Users] Quick booting

[conn intel]

Dear Friends,

I am using u-boot and it is first loading into the ram from flash and then
starts booting. The problem is its taking a lot of time in loading the image
from flash to ram and then starts booting from it. Following is the output
for printenv variables. I am new to u-boot and thus not much aware of it. On
other board there is redboot installed and it loads kernel in just flash and
starts booting the kernel.

Kindly let me know if you need any information.

Thank you,
Ankur.

# printenv
bootargs=root=/dev/mtdblock2 rw init=/linuxrc console=ttyS0,115200 mem=32M
rootfstype=jffs2
bootcmd=nand read.jffs2 0x30007FC0 0x80000 0x300000;bootm 0x30007FC0
bootdelay=5
baudrate=115200
ipaddr=10.0.1.8
serverip=10.0.1.2
netmask=255.255.255.0
partition=nand0,2
stdin=serial
stdout=serial
stderr=serial
Environment size: 304/2044 bytes



Snapshot of OUTPUT On BOARD:

NAND read: device 0 offset 0x80000, size 0x300000

Reading data from 0x37f800 -- 100% complete.
 3145728 bytes read: OK
## Booting image at 30007fc0 ...
   Image Name:   Linux-2.6.22.2
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    1382536 Bytes =  1.3 MB
   Load Address: 30008000
   Entry Point:  30008000
   Verifying Checksum ... OK
OK

Starting kernel ...
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[U-Boot-Users] Quick booting

[Jerry Van Baren]

conn intel wrote:
> Dear Friends,
> 
> I am using u-boot and it is first loading into the ram from flash and 
> then starts booting. The problem is its taking a lot of time in loading 
> the image from flash to ram and then starts booting from it. Following 
> is the output for printenv variables. I am new to u-boot and thus not 
> much aware of it. On other board there is redboot installed and it loads 
> kernel in just flash and starts booting the kernel.
> 
> Kindly let me know if you need any information.
> 
> Thank you,
> Ankur.
> 
> # printenv
> bootargs=root=/dev/mtdblock2 rw init=/linuxrc console=ttyS0,115200 
> mem=32M rootfstype=jffs2
> bootcmd=nand read.jffs2 0x30007FC0 0x80000 0x300000;bootm 0x30007FC0

Hi Ankur,

I have no experience with NAND/jffs2, but the following thread probably 
applies:
<http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/32434>

Summary: jffs2 is slow.  The thread has discussion of various options to 
speed up boot time.

Best regards,
gvb

[U-Boot-Users] Quick booting

[conn intel]

Dear Jerry Van Baren,

Thanks for your kind and quick response.

I read the thread and it is going to be very useful to me. Can we use DMA to
load image from flash to ram ?

Currently I am using following command to load kernel image from flash to
ram,

bootcmd=nand read.jffs2 0x30007FC0 0x80000 0x153000;bootm 0x30007FC0

Can someone suggest me better way to quicker the process?

Thank you,
Ankur.

On Wed, Feb 27, 2008 at 8:09 AM, Jerry Van Baren <gvb.uboot@gmail.com>
wrote:

> conn intel wrote:
> > Dear Friends,
> >
> > I am using u-boot and it is first loading into the ram from flash and
> > then starts booting. The problem is its taking a lot of time in loading
> > the image from flash to ram and then starts booting from it. Following
> > is the output for printenv variables. I am new to u-boot and thus not
> > much aware of it. On other board there is redboot installed and it loads
> > kernel in just flash and starts booting the kernel.
> >
> > Kindly let me know if you need any information.
> >
> > Thank you,
> > Ankur.
> >
> > # printenv
> > bootargs=root=/dev/mtdblock2 rw init=/linuxrc console=ttyS0,115200
> > mem=32M rootfstype=jffs2
> > bootcmd=nand read.jffs2 0x30007FC0 0x80000 0x300000;bootm 0x30007FC0
>
> Hi Ankur,
>
> I have no experience with NAND/jffs2, but the following thread probably
> applies:
> <http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/32434>
>
> Summary: jffs2 is slow.  The thread has discussion of various options to
> speed up boot time.
>
> Best regards,
> gvb
>
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[U-Boot-Users] Quick booting

[Detlev Zundel]

Hi "conn intel" and Jerry,

> Currently I am using following command to load kernel image from flash to ram,
>
> bootcmd=nand read.jffs2 0x30007FC0 0x80000 0x153000;bootm 0x30007FC0

These are actually two commands - the first one copies data from
NAND flash into RAM, but although the command name has a "jffs2" in it,
this really has nothing to do with the JFFS2 filesystem.  The command
does not parse the NAND storage as a filesystem, but simply respects the out
of band bad block markers in the NAND.  See doc/README.nand:

   nand read.jffs2 addr ofs|partition size
      Like `read', but the data for blocks that are marked bad is read as
      0xff. This gives a readable JFFS2 image that can be processed by
      the JFFS2 commands such as ls and fsload.

In the "bootm" it seems like you actually use that data transferred as a
Linux kernel.  (How do you know the offset 0x80000 is correct btw.?)
This kernel uses whatever is /dev/mtdblock2 as its rootfilesystem, which
is jffs2.  So the Linux kernel will need to parse JFFS2 and here the
comments from the thread Jerry mentioned apply, but the "nand
read.jffs2" does not suffer from any JFFS2 parsing.

If this is to slow for you, you have to at least tell us the platform
you're working on and then maybe the maintainer of this platform can
tell you whether he sees a chance to improve on pure nand read
performance.

Cheers
  Detlev

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