Re: [Qemu-discuss] Trouble getting ARM Linux kernel to boot

[Steven Frank]

The 3.5 kernel seemed to boot fine as well as one of the later 2.6 kernels I 
tried, I forget which one it was. 

I used the versatile_defconfig to build the kernel. Didn't change a thing. I 
still don't have a filesystem to use with it but it seemed to get all the way 
through the boot until it panicked because the fs was missing. 

I ran into the white screen hang again on my Mac at home when trying to 
recreate my QEMU build environment from work. I think adding --enable-cocoa to 
the QEMU config is what finally fixed it, in addition to the rest of the config 
from my last email. 

Not familiar with mtd, sorry.

Steven, via iPhone

On Sep 25, 2012, at 3:10 AM, Ezequiel Garcia <address@hidden> wrote:

> On Mon, Sep 24, 2012 at 9:34 PM, Steven Frank <address@hidden> wrote:
>> 
>> On Sep 21, 2012, at 5:51 PM, Ezequiel Garcia <address@hidden> wrote:
>> 
>> On Fri, Sep 21, 2012 at 7:03 PM, Steven Frank <address@hidden> wrote:
>> 
>> 
>> On Sep 21, 2012, at 11:59 AM, Ezequiel Garcia <address@hidden> wrote:
>> 
>> I am using a Mac OS X host to build the Linux 3.5 kernel for ARM, and trying
>> to boot it in QEMU 1.2.0.
>> 
>> The kernel, to my surprise, built fine on my Mac using the arm-none-eabi-gcc
>> toolchain from MacPorts.  I'm using the versatile_defconfig, since that
>> turned up a lot when I was Googling how to do this.
>> 
>> Then I try to boot my kernel in QEMU using this command line:
>> 
>>      arm-softmmu/qemu-system-arm -m 16 -M versatilepb -kernel
>> arch/arm/boot/zImage -serial stdio
>> 
>> I don't have a rootfs yet -- I was hoping to just get as far as seeing the
>> kernel boot messages.
>> 
>> It outputs this:
>> 
>>      Uncompressing Linux... done, booting the kernel.
>> 
>> Then hangs, with an empty white window.  Nothing further appears to happen.
>> 
>> 
>> I had the same problem just yesterday. Try with older kernel 2.6.32 /
>> 2.6.38 and let me know.
>> 
>> Also, what kernel config are you using?
>> 
>> 
>> I'm using the versatile_defconfig to (hopefully) match up with QEMU's
>> "versatilepb" machine.
>> 
>> I just tried 2.6.32 and 2.6.38.  Same results, although 2.6.32 outputs more
>> dots between "Uncompressing Linux" and "booting the kernel".  But both hang
>> at the blank white screen, just like 3.5 did.
>> 
>> There is one other interesting difference.  When trying to boot 2.6.32, QEMU
>> remains responsive.  In other words, it responds to events like Cmd-Q to
>> quit.  With the later kernels, QEMU hangs completely and must be force-quit
>> (killed).
>> 
>> Very curious.  Any thoughts?
>> 
>> 
>> It was working yesterday. Let me check my qemu / kernel version and
>> the parameters
>> I'm using....
>> 
>> 
>> I think I finally located the problem.
>> 
>> The QEMU binary is defective when built with Apple's LLVM-based toolchain,
>> as documented here:
>> 
>> https://bugs.launchpad.net/qemu/+bug/925412
>> 
>> My workaround was to install gcc 4.8 using MacPorts:
>> 
>> sudo port install gcc48
>> 
>> Configure and build QEMU like so:
>> 
>> ./configure --disable-sdl --disable-kvm --target-list=arm-softmmu
>> --cc=x86_64-apple-darwin12-gcc-4.8.0
>> --host-cc=x86_64-apple-darwin12-gcc-4.8.0
>> 
>> And now I can boot my compiled-from-source Linux kernel.
>> 
> 
> Nice! Which kernel version are you using?
> Care to send your kernel config?
> 
> Also, have you tried mtd emulated devices? I had some problems with it.
> 
> Ezequiel.