Re: [Qemu-devel] Ubuntu 14.04 LTS Arm for Raspberry - QEMU Support

[Andrew Baumann]

Hi Vincenzo,

> From: Vincenzo Calabrò [mailto:address@hidden 
> Sent: Wednesday, 16 March 2016 12:39 PM
[...]
> 1. I'm using the "official" arm ubuntu 14.04 
> (https://wiki.ubuntu.com/ARM/RaspberryPi) - you can download the image from 
> that link and follow the instruction to flash a SD card.... yes I'm using the 
> SD card instead of the image on the host. The reason is I want to emulate the 
> RPi with its real SD card.

Ok. Using the SD card should be fine, but I have never tested the Ubuntu image 
before, just an (older) version of Raspbian.

> 2. after copying the kernel7.img and the bcm2709-rpi-2-b.dtb file into a 
> "boot" folder, I use the following command with the lastest (up to one day 
> ago) qemu:
> qemu-system-arm \
> -kernel boot/kernel7.img \
> -dtb boot/bcm2709-rpi-2-b.dtb \
> -M raspi2 -m 256 \

Why are you emulating a 256MB pi2? Does such a configuration exist? I thought 
they all had 1GB of RAM.

> -no-reboot -serial stdio \
> -append "rw earlyprintk loglevel=8 console=ttyAMA0,115200 
> dwc_otg.lpm_enable=0 root=/dev/mmcblk0p2 panic=1 rootfstype=ext4" \
> -hda /dev/sdb \
> -net nic -net 
> user,net=http://10.0.0.0/8,host=10.0.0.1,hostfwd=tcp:127.0.0.1:2222-10.0.0.2:22

[...]
> [    5.109543] bcm_power: Broadcom power driver
> [    5.111766] bcm_power_open() -> 0
> [    5.112687] bcm_power_request(0, 8)

This is a known (albeit only as of Peter's email to me slightly earlier today 
:) issue, since we don't model the power management unit in mainline qemu.

There is a trivial emulation for it in the raspi branch here:
https://github.com/0xabu/qemu ... I would be curious to know whether you fare 
any better with this version?

Cheers,
Andrew