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Re: [Qemu-devel] Hack integrating SeaBios / LinuxBoot option rom with QE
From: |
Kevin O'Connor |
Subject: |
Re: [Qemu-devel] Hack integrating SeaBios / LinuxBoot option rom with QEMU trace backends |
Date: |
Mon, 10 Oct 2011 19:57:53 -0400 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Mon, Oct 10, 2011 at 06:08:03PM +0100, Daniel P. Berrange wrote:
> I've been investigating where time disappears to when booting Linux guests.
>
> Initially I enabled DEBUG_BIOS in QEMU's hw/pc.c, and then hacked it so
> that it could print a timestamp before each new line of debug output. The
> problem with that is that it slowed down startup, so the timings I was
> examining all changed.
A lot of effort went into optimizing SeaBIOS boot time. There is a
tool in seabios git to help with benchmarking - tools/readserial.py.
The tool was designed for use with serial ports on real machines using
coreboot, but it works with qemu too:
mkfifo seabioslog
./tools/readserial.py -nf seabioslog
qemu-system-x86_64 -chardev pipe,id=seabios,path=seabioslog -device
isa-debugcon,iobase=0x402,chardev=seabios -hda myimage
This will show the SeaBIOS debug output with timing info.
-Kevin
- Re: [Qemu-devel] Slow kernel/initrd loading via fw_cfg; Was Re: Hack integrating SeaBios / LinuxBoot option rom with QEMU trace backends, (continued)
- Re: [Qemu-devel] Slow kernel/initrd loading via fw_cfg; Was Re: Hack integrating SeaBios / LinuxBoot option rom with QEMU trace backends, Blue Swirl, 2011/10/15
- Re: [Qemu-devel] Slow kernel/initrd loading via fw_cfg; Was Re: Hack integrating SeaBios / LinuxBoot option rom with QEMU trace backends, Richard W.M. Jones, 2011/10/15
- Re: [Qemu-devel] Slow kernel/initrd loading via fw_cfg; Was Re: Hack integrating SeaBios / LinuxBoot option rom with QEMU trace backends, LluĂs Vilanova, 2011/10/16
- Re: [Qemu-devel] Hack integrating SeaBios / LinuxBoot option rom with QEMU trace backends, Avi Kivity, 2011/10/11
- Re: [Qemu-devel] Hack integrating SeaBios / LinuxBoot option rom with QEMU trace backends, Daniel P. Berrange, 2011/10/11
- Re: [Qemu-devel] Hack integrating SeaBios / LinuxBoot option rom with QEMU trace backends, Avi Kivity, 2011/10/11
Re: [Qemu-devel] Hack integrating SeaBios / LinuxBoot option rom with QEMU trace backends,
Kevin O'Connor <=