L4Android bootstrap errors

giowck giowckln at googlemail.com
Mon Sep 5 14:51:39 CEST 2011


Hi,

first of all, thanks for your answer!


Am 29.08.2011 20:32, schrieb Matthias Lange:
> Hi,
>
> On 08/28/2011 02:17 PM, giowck wrote:
>> Hi,
>>
>> I'm trying to get L4Android working on a BeagleBoard (rev. C4).
>> After some minor issues, I finally managed to build L4Re, Fiasco.OC,
>> L4Linux and L4Android successfully. Everything works great on my board,
>> including L4Linux.
>> But L4Android gives me some errors during the bootstrap:
>>
>> io      | Io service
>> io      | L4Re[rm]: unhandled read page fault @40000c pc=102b4c8
>> io      | L4Re: unhandled exception: pc=0x102b4c8
>>
>> Please see [1] for the full bootstrap (target: ARM beagleboard).
>
>  From your boot log I can see that you are using the wrong devs file. You
> need to create one matching the configuration of your BeagleBoard.
> However you will have a hard time getting L4Android to run with only
> 128MB of RAM.

The BeagleBoard I'm using has 256MB of RAM, but as it seems, only 128MB 
are detected. I'll look on that later.

There's a 'arm-omap3.devs' file in the 
'l4re-snapshot-2011081207/src/l4/pkg/io/config' directory. I'll try to 
modify and use that file, better than writing a new .devs file from scratch.

>
>> To exclude some hardware related issues, I rebuilt L4Android with
>> realview board (ARM) as target, in order to test it using qemu. This
>> time, I get the following error:
>>
>> android | L4Re: unhandled exception: pc=0xa80001c8
>>
>> Please see [2] for the full bootstrap (target: ARM realview board).
>
> Can you tell me what's at 0xa80001c8 in your L4Android kernel?

I'm not that experienced with debugging tools. I tried to disassembly 
the L4Android vmlinux binary, using objdump, but found nothing at 
'0xa80001c8' as offset. See 
http://dl.dropbox.com/u/1511663/vmlinux.decoded for the disassembled 
vmlinux.

Anyway I uploaded the vmlinux file to 
http://dl.dropbox.com/u/1511663/vmlinux, just in case more info is needed.

>
>> Would be nice if someone could build L4Android for realview-b and tell
>> me if it works in qemu. Maybe those errors are related to my newbieness :D
>>
>> Just another thing. On the L4Android Website, in the 'build diskimage'
>> instructions, you write:
>> "Next we need to modify the init.rc script. Mount the newly created
>> image and locate the section where the system and data partition are to
>> be mounted and replace the commands with the lines following the mount:"
>>
>> mount cramfs /l4bdds0 /system
>> mount cramfs /l4bdds0 /system ro remount
>> mount tmpfs tmpfs /data size=32M
>>
>> Then I saw that on your prebuilt root/system images for x86, the "on fs"
>> section of the init.rc file is empty:
>
> The original content has already been removed in that init script. You
> just need to enter the lines mentioned on the website.
>
>> on fs
>> # mount mtd partitions
>>
>> So, i could not compare the section with mine, which looks the following:
>>
>> on fs
>> # mount mtd partitions
>> # Mount /system rw first to give the filesystem a chance to save a
>> checkpoint
>> #    mount yaffs2 mtd at system /system
>> #    mount yaffs2 mtd at system /system ro remount
>> #    mount yaffs2 mtd at userdata /data nosuid nodev
>> mount cramfs /l4bdds0 /system
>> mount cramfs /l4bdds0 /system ro remount
>> mount tmpfs tmpfs /data size=32M
>>
>> mount yaffs2 mtd at cache /cache nosuid nodev #unchanged
>
> You should remove the above line as well.

OK.

>
> Br,
> Matthias.

By the way, after I saw that the L4Android code has been updated to work 
with the latest l4re snapshot, I updated my working directory (ARM 
realview for qemu), but the same boot error still persists (with the 
same exception and offset).

Thank you!
Giorgio

>
>>
>> Anyway, I tried to empty the "on fs" section like on the prebuilt
>> images, but the above errors still persist.
>> So any idea about those errors?
>>
>> Thank you!
>> Giorgio
>>
>> Build environment in use
>> ========================
>> - L4Re/L4Linux/Fiasco.OC: l4re-snapshot-2011062216 (not the last
>> revision, since l4android needs to be updated)
>> - L4Android: latest available revision (19 Jul 2011)
>> - Compiler: CodeSourcery (arm-2010.09-50-arm-none-linux-gnueabi)
>> - OS: Ubuntu 11.04 x86
>>
>> [1] http://pastebin.com/95M7iiPv
>> [2] http://pastebin.com/eYvM65ij
>>
>>
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