On Fri, 13 Jan 2023 at 12:05, Norman Feske norman.feske@genode-labs.com wrote:
Hi again,
Kernel: MMU-fault not handled ESR=0x92000061 Kernel: init -> drivers -> gui_fb -> ep raised unhandled MMU fault ip=0x1009bb4 fault-addr=0x113d76ac type=unknown
[...]
Maybe the fault IP refers to some special (neon?) instruction with tighter constraints? Have you had a look at the faulting instruction?
Sorry , for being uneducated, but is "ip" an instruction (doesn't make sense , isn't an opcode) or is it an address? If address, where can I look it up?
just noticed that I left your question unanswered.
IP stands for "instruction pointer". It is printed in the page-fault message (in this case 'ip=0x1009bb4').
When I see such an address, I'm usually using objdump to look up the code around it, using the debug version of binary. In this case:
build/arm_v8a$ genode-aarch64-objdump -lSd debug/gui_fb | less
In less, I search for '1009bb4', where I can see both the source line numbers around the IP (scrolling back helps sometimes for heavily inlined code), and also the opcode of the instruction at the IP.
However, if my guess of the previous posting is correct, the particular instruction is probably innocent.
Thanks , again. USB is currently a mess. I started from older imx8 driver which depends on u-boot to start. I use u-boot "usb start" before boot. But it works :-)
Congratulations, it's a miracle! :)
Thanks I am happy! I have worked with this for 9 days and 9 nights since the first serial output. I will try to devise a platform driver .. I think I already did this ( but not right now, things got bad for unknown reasons , so reverted ).
Michael