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[Qemu-devel] Running u-boot on raspi2
From: |
Bonnans, Laurent |
Subject: |
[Qemu-devel] Running u-boot on raspi2 |
Date: |
Fri, 23 Aug 2019 15:52:59 +0000 |
Hi,
We (mostly Cheng Xiang's work) have been trying to use the raspi2
machine to boot an image through u-boot.
It seems, however, that there are some missing pieces:
The first problem is that it trips very early if we keep the cpus count
at 4 but will continue if we hard-patch it to be a single core.
Symptom is that it seems all cores are running and trying to execute
something, while u-boot probably has not intention of doing something
with SMP.
Our guess is that it's something related to the asm spin routine in
raspi.c, which is maybe awoken too soon by some event in the mbox?
Second problem is that u-boot relies on some SoC timer for the
raspberrypi 2, "System Timer" in
https://www.raspberrypi.org/app/uploads/2012/02/BCM2835-ARM-Peripherals.pdf
It has not been added to qemu, to our knowledge but it looks like it
should be pretty easy to emulate.
If we remove the timer accesses on u-boot + sets the cpu count to 1, the
machine boots fine up to the kernel (minus the PLL related warning
mentioned earlier in the list).
The first issue seems harder to resolve. Does anybody have a clearer
picture on what could be the problem?
Cheers,
Laurent
- [Qemu-devel] Running u-boot on raspi2,
Bonnans, Laurent <=