Stefan and Grant,
I have made some progess, Linux can boot normally with 1 GB memory now. The following is what I did: 1.Chang "Maximum low memory size" from 0x30000000(768M) to 0x20000000(512M) and enable High Memory support for Linux kernel configuration. 2.Add "CONFIG_VERY_BIG_RAM" to U-Boot configuration file, or change U-Boot Env. variable "initrd_high" from 0x30000000 to 0x20000000. This step is to make sure Linux can find ramdisk and I don't think it's critical for my issue.
Now, my question is do you think I have found root cause of my issue? I mean incorrect setting of "Maximum low memory size".
Best Regards,
Sun
From: sr@denx.de To: u-boot@lists.denx.de Subject: Re: [U-Boot] Help!Some memory doesn't work on PPC405Ex based board! Date: Thu, 23 Apr 2009 11:55:35 +0200 CC: sunwx2001@hotmail.com; support@amcc.com; gerickson@nuovations.com
On Thursday 23 April 2009, SunNeo wrote:
Have performed a slow memory post using code in post/drivers/memory.c, still no error.
Another idea: Did you also try using DDR autocalibration method A? Standard is method B but A takes a lot longer. (See the Method_A and Method_B algorithm discription in the file cpu/ppc4xx/4xx_ibm_ddr2_autocalib.c). Perhaps this gives some further results.
I found memsize in post/driver/memory.c has a limit of 256MB, so I modify it to 1024M.
Have tried Linux-2.6.29, same result.
Hmmm. You should perhaps try to debug further where exactly this error is occurring. Via printk's or JTAG debugger. If this error always happens at the same location it could perhaps be located (if it's not a memory problem) in the kernel source code.
Best regards, Stefan
===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office@denx.de =====================================================================
_________________________________________________________________ 上Windows Live 中国首页，下载最新版Messenger！ http://www.windowslive.cn