2008-09-16 20:54:17     reading CONFIG_LOGBUFFER in linux?

Document created by Aaronwu Employee on Sep 18, 2013
Version 1Show Document
  • View in full screen mode

2008-09-16 20:54:17     reading CONFIG_LOGBUFFER in linux?

Pawel Pastuszak (CANADA)

Message: 62272   

 

Hi all,

 

I enable CONFIG_LOGBUFFER support on the blackin in U-boot and i would like to read this information back in the kernel space. But each time that i read it give me zero.

 

 

 

Any items?

 

here is some example of the kernel module

 

for (i =0; i < LOGBUFF_RESERVE; i++) {

         s = (char *)((128 * 1024 * 1024 ) - LOGBUFF_RESERVE) + i ;

 

         if ( !(i % 100 ))

             printk("\n%x: \n", s);

 

 

         printk(" %x ", *s);

    }

printk("\n");

 

All displays zeros...

 

I known denx has a patch for linux but that adjustes memory from MMU_init....

 

Note i have 128 MB with BF537 rev 1.0.3

 

 

QuoteReplyEditDelete

 

 

2008-09-16 21:00:59     Re: reading CONFIG_LOGBUFFER in linux?

Mike Frysinger (UNITED STATES)

Message: 62273   

 

the kernel doesnt know anything about the log buffer used in u-boot.  you would need to copy the u-boot buffer during early kernel init to somewhere the kernel does know about.

QuoteReplyEditDelete

 

 

2008-09-17 09:38:31     Re: reading CONFIG_LOGBUFFER in linux?

Pawel Pastuszak (CANADA)

Message: 62310   

 

thanks mike for the tip.

 

It works now.

Attachments

    Outcomes