I am increasingly suspicious that the uboot that is built by create_uboot is not happy with rev D1 of the wandboard quad. The SPL first stage, installed in sector 1 per instructions at contrib/uboot/board/wandboard, seems to be a non-starter: no serial output at all. The source code suggests it knows about rev B1 and C1, and anything that is not rev C1 is assumed to be rev B1.
Using the bootstrap from the wandboard Debian, the u-boot.img from create_uboot will load, and provides the messages shown below. It is clearly having difficulties doing some i2c transaction. MMC commands beyond "info" all hang the cpu, so no Genode loading possible.
* * * * * * * * * * * * * * * * * * * * * * * * *
U-Boot SPL 2015.04-gc42b934 (May 02 2017 - 11:51:42) reading u-boot.img reading u-boot.img
U-Boot 2015.10-rc4-gd797dd5 (Aug 18 2017 - 14:10:37 -0500)
CPU: Freescale i.MX6QP rev1.0 at 792 MHz Reset cause: POR Board: Wandboard rev B1 I2C: ready DRAM: 2 GiB MMC: FSL_SDHC: 0, FSL_SDHC: 1 *** Warning - bad CRC, using default environment
wait_for_sr_state: failed sr=81 cr=a0 state=2020 i2c_init_transfer: failed for chip 0x10 retry=0 wait_for_sr_state: failed sr=81 cr=a0 state=2020 i2c_init_transfer: failed for chip 0x10 retry=1 wait_for_sr_state: failed sr=81 cr=a0 state=2020 i2c_init_transfer: failed for chip 0x10 retry=2 i2c_init_transfer: give up i2c_regs=0x21a4000 No panel detected: default to HDMI Display: HDMI (1024x768) In: serial Out: serial Err: serial Net: FEC [PRIME] Hit any key to stop autoboot: 0 => * * * * * * * * * * * * * * * * * * * * * * * * *
Maybe there is something else missing....
Happily, the uboot that came with Debian is able to load and start my application uImage (seL4)--this is a good enough work-around for me for now.
I did notice two, apparently non-fatal, Genode errors: ... [init] child "timer" announces service "Timer" Error: mapping failed 0x4a9000 -> 0xa6000 Error: mapping failed 0x476000 -> 0x73000 ...
This seems like a different topic. I'll start another thread if anyone has cycles to look at this.
// Steve
On 08/21/2017 04:49 AM, Martin Stein wrote:
We have a Serial-to-USB cable connected to the Serial interface of the board and a USB port of the testing machine. Then you can catch the output via 'picocom' for instance. The implementation of the UART driver is [1]. It uses 1 stop bit, a baudrate of 115200, and no parity. So, the following works for me:
sudo picocom -p n -b 115200 /dev/ttyUSB0
Even if your Genode doesn't come up you should at least see some output from the Uboot like this:
U-Boot 2015.10-00237-g92e40f5-dirty (Dec 04 2015 - 15:37:04 +0100) CPU: Freescale i.MX6Q rev1.2 at 792 MHz Reset cause: POR Board: Wandboard rev B1 I2C: ready DRAM: 2 GiB MMC: FSL_SDHC: 0, FSL_SDHC: 1 No panel detected: default to HDMI Display: HDMI (1024x768) In: serial Out: serial Err: serial Net: FEC [PRIME] Hit any key to stop autoboot: 1 U-Boot SPL 2015.10-00237-g92e40f5-dirty (Dec 04 2015 - 15:37:04)