Re: [Qemu-devel] Booting custom kernel in qemu

[Apelete Seketeli <apelete@seketeli.org>]

On 27-May-11, Amit Shah wrote:
> On (Thu) 26 May 2011 [21:59:01], Apelete Seketeli wrote:
> > Hello,
> > 
> > I'm trying to boot a custom linux kernel in qemu, and I plan to
> > contribute the necessary work to make it work (this is the first step
> > I'm taking to add OS support in qemu). I'm totally new to qemu, and I
> > haven't found enough information to know how to start debugging the
> > thing, so I thought of asking here.
> > 
> > I wanted to launch the kernel in a terminal for practical purposes, so
> > I tried:
> > 
> > qemu -kernel bzImage -append console=ttyS0
> 
> Add -serial stdio to get those logs.

Well,

qemu -kernel bzImage -append console=ttyS0 -serial stdio

does not give me any output, I guess it's because the thing get stuck
early during the boot process. For the time being I'm using

qemu -kernel bzImage -append console=ttyS0 -S -nographic

in order to launch gdbserver in the monitor and attach a gdb in the
host; I hope I'll be able to follow the boot process in the debugger
and understand qemu inner workings.

I have a question though:

$ qemu -S -kernel arch/x86/boot/bzImage -append console=ttyS0 -nographic -serial stdio
chardev: opening backend "stdio" failed
qemu: could not open serial device 'stdio': No such file or directory

Why do I get an error since stdio is (according to the manual) the
standard device in non graphical mode ? 

-- 
        Apelete