[U-Boot-Users] prob. faced in UBoot with 64MB SDRAM
Hello,
I m using U-Boot 1.1.2 for custom board similar to MPC8272ADS board.
On board it has 64MB Micron SDRAm and 16MB AMD flash.
When Uboot is configured for 16MB SDRAM it works fine.
A)But the same Uboot after doing necessary changes in OR1 to configure it for 64MB SDRAM.it fails to comeup properly.
So for 16MB OR1:0xFF0030C0 for 64MB OR1:0xFC002CC0
and other SDRAM register value remain the same
BR1 0x00001841 PSDMR 0x8266B73E
PSRT 0x4B
MPTPR 0x1300
when we debugged the Uboot through BDI we found that it always hangs after relocating the code in SDRAM. but we ar not sure what could be the reason.....
B) Also we found that same uboot for second board with same SDRAM and FLASH it comes up properly. And after configuring boot arguements environment variables.It will download the kermel image and after uncompressing kernel image and mount NFS properly. But when the root prompt comes board will get reset and again start executing uboot. and this get repeated in a loop.
C) One more observation on the second board where uboot comes up properly and kernel +Ramdisk boot arguments are configured. both kernel +Ramdisk image will be copied from tftp and start executing properly without any problem.
As far as HW is concerned both the board is same w.r.t to components mounted.
kindly help in this respect with possible solution.
Thanking you.
Nethra wrote:
Hello,
I m using U-Boot 1.1.2 for custom board similar to MPC8272ADS board.
On board it has 64MB Micron SDRAm and 16MB AMD flash.
When Uboot is configured for 16MB SDRAM it works fine.
A)But the same Uboot after doing necessary changes in OR1 to configure it for 64MB SDRAM.it fails to comeup properly.
So for 16MB OR1:0xFF0030C0 for 64MB OR1:0xFC002CC0
and other SDRAM register value remain the same
BR1 0x00001841 PSDMR 0x8266B73E
PSRT 0x4B
MPTPR 0x1300
when we debugged the Uboot through BDI we found that it always hangs after relocating the code in SDRAM. but we ar not sure what could be the reason.....
B) Also we found that same uboot for second board with same SDRAM and FLASH it comes up properly. And after configuring boot arguements environment variables.It will download the kermel image and after uncompressing kernel image and mount NFS properly. But when the root prompt comes board will get reset and again start executing uboot. and this get repeated in a loop.
C) One more observation on the second board where uboot comes up properly and kernel +Ramdisk boot arguments are configured. both kernel +Ramdisk image will be copied from tftp and start executing properly without any problem.
As far as HW is concerned both the board is same w.r.t to components mounted.
kindly help in this respect with possible solution.
Thanking you.
Hi Nethra,
Your SDRAM initialization sequence (PSDMR & friends) is most likely wrong for the new RAM devices. What worked with the 16MB SDRAM is not going to work with the 64MB SDRAM, timing parameters are nearly 100% guaranteed to be different. http://www.denx.de/wiki/view/DULG/UBootCrashAfterRelocation
Best regards, gvb
participants (2)
-
Jerry Van Baren -
Nethra