Examples 6 and 7 not working in RPI4B about rust-raspberrypi-os-tutorials

[andre-richter]

Hi @CPerezz,

that's strange. I just re-tested it on my Pi4. I loaded the newest versions of start4.elf, fixup4 and the dtb.
It works for me, and it doesn't make a difference if the start is named start.elf or start4.elf.

• Do you have any other files on SD card?
• Are you ejecting the SD card properly after writing to it from the host? This can often cause issues because the contents are not flushed onto the SD but reside in the OS cache when you don't eject/flush properly.

[CPerezz]

Hi @andre-richter , thanks for answering.

No other files are there:

> ls -la /run/media/boot/$USER
Permissions Size User Date Modified Name
.rw-r--r--   47k kr0   7 Nov 21:22  bcm2711-rpi-4-b.dtb
.rw-r--r--    56 kr0   8 Nov  0:26  config.txt
.rw-r--r--  5.4k kr0   7 Nov 21:22  fixup4.dat
.rw-r--r--  8.2k kr0   8 Nov  0:20  kernel8.img
.rw-r--r--  2.2M kr0   7 Nov 21:22  start.elf

Also. After writing/copying files to the SD I just do sudo umount /run/media/boot and eject the USB adapter that has the SD card in it.

Will try to re-do completely from scratch example 6 and 7 later today to see what happens. But at this point. I tried everything. So if I can provide any other info that might help the debugging. Just tell me. Since it's weird, and also difficult to check since qemu doesn't support rpi4 on the -M option.

[CPerezz]

kk after doing everything from scratch again:

Example 6

I probably did something wrong since now I'm capable of booting the RPI4B and the Enter triggers the execution as expected breaking the infinite loop. Although the prints are indented and so the output looks like:

Output 1
               Output 2
                               Output 3
                                               Output 4

But it's fine. I played a bit with the println! macro to try to see why this happens but haven't been able to catch it yet.

Example 7

The kernel boots correctly if I load it in the SD and use screen as in example 6.

But when I run BSP=4 make chainboot i keep getting the same errors:

Minipush 1.0

[MP] ⏳ Waiting for /dev/ttyUSB0
[MP] ✅ Connected



[MP] ⚡ Protocol Error: Remove and insert the USB serial again
[MP] ⏳ Waiting for /dev/ttyUSB0
[MP] ✅ Connected

[MP] ⚡ Protocol Error: Remove and insert the USB serial again




[MP] ⏳ Waiting for /dev/ttyUSB0
[MP] ✅ Connected

[MP] ⚡ Protocol Error: Remove and insert the USB serial again



^C
[MP] Bye 👋
^C
make: *** [Makefile:104: chainboot] Error 

[andre-richter]

Hi @CPerezz,

I was able to reproduce the odd line breaks in tutorial 6. A while ago, I changed all the kernel sources to conclude a line only with \n, and not print an explicit carriage return. The terminal part of minipush accounted for it, but I never realized that it breaks screen.

I carved out the terminal part of minipush for tutorial 6, so connection to the RPi now happens through an in-house tool as well. Please check out if the changes introduced in e147309 work for you.

Regarding tutorial 7, hard to say why this still fails. Even more so because tutorial 6 seems to work...

[abdes]

@andre-richter thanks again for doing these tutorials. Maybe this is related to my issue #81 ?

[andre-richter]

@CPerezz,

can you check if something changes when you use this kernel8.img as the chainloader on your Pi4 SD card? changed when you checkout master now?

163e201 added the changes @abdes reported in #81.

[andre-richter]

Closing this for now since no feedback received.

We can reopen anytime if needed.

[CPerezz]

Hi @andre-richter I've been extremely busy. That's why I haven't been able to test your changes. I'll do ASAP. Sorry for the delay.