topic Re: Read the values from RCW in Linux (LS1028A) in Layerscape

Read the values from RCW in Linux (LS1028A)

yuvarajesh_vall — Thu, 16 Apr 2020 18:25:19 GMT

Hi,

Is there a possibility to read the values from the RCW register in Linux.

The objective is to check if the RCW setting is correct.

Thank you

Rajesh

Re: Read the values from RCW in Linux (LS1028A)

yipingwang — Fri, 17 Apr 2020 08:05:47 GMT

1. U-boot log - the RCW is printed out by u-boot - is enough to have a serial console (set it up to 115200 baudrate) and a working u-boot

2. CodeWarrior - attach to your board using the Attach connection and read the RCW from Registers View.

For CodeWarrior IDE configuration, you could refer to CodeWarrior IDE configuration in the section "3. Debug Linux Kernel by Attaching Running U-boot" in https://community.nxp.com/docs/DOC-331981 .

Re: Read the values from RCW in Linux (LS1028A)

yuvarajesh_vall — Fri, 17 Apr 2020 16:56:20 GMT

Hi Yiping Wang,

Thank you for your answer. By our goal is to read the rcw register from linux part. I found a tool memrw(grub-core/commands/memrw.c · 40211ab884a81e4653421ce4af2aa3caed397fba · Debian GRUB Maintainers / grub · GitLab ) to read the physical memory. is it helpful to read the rcw from linux ? If yes, how can i read the RCW from Linux?

Regards,

Rajesh

Re: Read the values from RCW in Linux (LS1028A)

yipingwang — Mon, 20 Apr 2020 07:03:58 GMT

RCW registers are not memory mapped registers.

I assume that RCW is deployed on flash, you could refer to the following procedure to dump flash memory.

$ dd if=/dev/mtd0 of=file bs=512 count=1

b25805@star:~$ xxd file
00000000: 55aa 55aa 0000 1080 1040 003c 3000 0000 U.U......@.<0...
00000010: 0000 0000 0000 0000 0000 0000 0000 8f01 ................
00000020: 00c0 3000 0000 0000 a031 2002 8025 0000 ..0......1 ..%..
00000030: 0000 0000 9632 0000 0000 0000 1000 0000 .....2..........
00000040: 0000 0000 0000 0000 0000 0000 0000 0000 ................
00000050: 0000 0000 0000 0000 0000 0000 0000 0000 ................
00000060: 0000 0000 0000 0000 0000 0000 0000 0000 ................
00000070: 0070 0e00 0000 0000 0000 58bb 0000 0000 .p........X.....
00000080: 0000 0000 0000 0000 5ba4 ac25 9008 4033 ........[..%..@3
00000090: 0104 8000 9008 5033 0104 8000 bc08 4033 ......P3......@3
000000a0: 0100 0000 5401 4033 4747 4747 5801 4033 ....T.@3GGGGX.@3

Thanks,

Yiping