rust-embedded/rust-raspberrypi-OS-tutorials

Examples 6 and 7 not working in RPI4B

CPerezz opened this issue · 8 comments

CPerezz commented

Hey. Firs of all, thanks for this great tutorial. Is really fun & interesting!!

As for the problems I'm experiencing:

Example 6

  • Ran BSP=rpi4 make and copied kernel8.img together with fixup4.dat, start4.elf (renamed to start.elf as per README comment) and bcm2711-rpi-4-b.dtb and config.txt with the specified contents to the SD.
  • Ran sudo screen /dev/ttyUSB0 230400. Black screen appears and then after pressing Enter nothing happens.

I tried with start4.elf and doesn't work. Also tried to download the latest firmware and same outcome..

Example 7

  • Ran BSP=rpi4 make and copied the kernel8.img to the SD.
  • Ran BSP=rpi4 make chainboot and this was the outcome:
BSP=rpi4 make chainboot
Minipush 1.0


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

[MP] ⚡ Protocol Error: Remove and insert the USB serial again
^C
[MP] Bye 👋

The error is very similar to what I've seen in #79 . I checked whether I had everything correct with the toolchains and targets and the rest of the config. But since I've seen new commits have been done since this issue was close, maybe one of them broke this.

If you need any kind of extra info, just ping me. Sorry that I cannot provide more, but I don't really know how to debug it.

andre-richter commented

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 commented

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 commented

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 commented

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 commented

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

andre-richter commented

@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 commented

Closing this for now since no feedback received.

We can reopen anytime if needed.

CPerezz commented

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.