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Old 10-09-2019, 05:12 AM   #26
smindux
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smindux began at the beginning.
 
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Meanwhile I managed to build u-boot that is provided by lab126 as per instructions in this previous post.
However as you might expect I could not boot it.

The debugging example Philippe provided is great and very enlightening, yet I get very different output.
Quote:
IN:
0x80404938: 00000000 andeq r0, r0, r0

R00=00000000 R01=00000000 R02=00000000 R03=00000000
R04=00000000 R05=00000000 R06=00000000 R07=00000000
R08=00000000 R09=00000000 R10=00000000 R11=00000000
R12=00000000 R13=00000000 R14=00000000 R15=80404938
PSR=400001d3 -Z-- A S svc32
Which leads me to the conclusion that I am making some dumb mistake/decision somewhere along the way.
In addition to what Philippe suggested for enabling debugging on QEMU I enabled debugging in u-boot as well
Code:
CFLAGS+= -DCONFIG_LOG -DDEBUG -DCONFIG_LOGLEVEL=8 -DCONFIG_LOG_CONSOLE -DCONFIG_MAX_LOG_LEVEL=8
And I get utter silence ...

Next step is either someone points out my stupidity or I attach gdb to QEMU and try my chances ... not very optimistic about this last one.

As far as I understood the topic about idme - it is fluid enough to be able to set/modify it after kernel boot.

Introductory ARM Assembly if you want to dive.
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