Need advise with u-boot on SH-7785LCR

[John Paul Adrian Glaubitz]

Hello!

I am Debian's maintainer for the SuperH (sh4) port as well as one of the upstream
maintainers of SuperH support in the kernel. I own various SuperH boards with one
of them being the Renesas SH-7785LCR board which used to be supported by u-boot
up to including v2019.01.

My board is currently running v2014.01 with the following output:

U-Boot 2014.01 (Jan 30 2015 - 11:01:14)

CPU: SH4
BOARD: Renesas Technology Corp. R0P7785LC0011RL
DRAM:  384MB
Flash: 64MB
PCI: SH7780 PCI host bridge found.
PCI:   Bus Dev VenId DevId Class Int
  00:00.0     - 10ec:8169 - Network controller
  00:01.0     - 1095:3512 - Mass storage controller
In:    serial
Out:   serial
Err:   serial
Net:   RTL8169#0
Warning: RTL8169#0 MAC addresses don't match:
Address in SROM is         00:00:87:6b:bd:72
Address in environment is  74:90:50:00:02:03

Hit any key to stop autoboot:  0 
=> printenv
baudrate=115200
bootargs=console=ttySC1,115200 root=/dev/sda1 ip=dhcp
bootcmd=usb reset; fatload usb 0:1 0x89000000 uImage-git.gz; pmb ; bootm
bootdelay=3
bootdevice=0:1
ethact=RTL8169#0
ethaddr=74:90:50:00:02:03
stderr=serial
stdin=serial
stdout=serial
usbload=usb reset; fatload usb 0:1 0x89000000 uImage-git.gz; pmb ; bootm
ver=U-Boot 2014.01 (Jan 30 2015 - 11:01:14)

Environment size: 396/262140 bytes
=>

I am currently running into the problem that u-boot hangs after verifying the image
checksum when trying to boot a cross-built kernel. This has happened in the past before
while often the kernel would boot just fine after performing some resets.

When the boot hangs, it looks like this:

=> usb reset; fatload usb 0:1 0x89000000 uImage-next.gz ; pmb ; bootm
(Re)start USB...
USB0:   scanning bus 0 for devices... 2 USB Device(s) found
       scanning usb for storage devices... 1 Storage Device(s) found
reading uImage-next.gz
4348967 bytes read in 2470 ms (1.7 MiB/s)
## Booting kernel from Legacy Image at 89000000 ...
   Image Name:   Linux-6.6.0-rc1-00007-g63f1ee206
   Image Type:   SuperH Linux Kernel Image (gzip compressed)
   Data Size:    4348903 Bytes = 4.1 MiB
   Load Address: 80001000
   Entry Point:  80002000
   Verifying Checksum ... OK
(hangs)

My first attempt at fixing this would be upgrading the board to v2019.01.

Unfortunately, I have not found any documentation yet which explains how to upgrade
the u-boot firmware on this particular board. Does anyone know whether there are
any tools for this available? I can see an "erase" command in the u-boot command
list, but there is no command for writing a new u-boot firmware to flash.

I have already reached out to Nobuhiro Iwamatsu who is the original author of support
for these boards in u-boot and also provided me with the particular hardware. However,
I haven't heard back from him yet.

Another question that I have is the loading address. I need to load the kernel to the
loading address 0x89000000 as otherwise the machine won't boot. However, according to
the output of the u-boot mkimage tool, the loading address is 0x80001000 and not
0x8900000. Could the different addresses be related to the unusual memory layout
of this board which has to be switched with the "pmb" command prior boot?

Also, I was wondering what it would take to convert this particular board to CONFIG_DM_USB
and CONFIG_DM_PCI. I would be interested in getting support for SuperH boards in u-boot
into a better shape with broader hardware support.

>From the kernel side, we're currently working on converting SuperH to Device Trees, so I'm
expecting SuperH Linux to be better suited to modern versions of u-boot in the future.

For now, it would be a great help if anyone could help me with the hanging boot issue.

Thanks,
Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer
`. `'   Physicist
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913