[LEDE-DEV] [PATCH 1/2] armvirt: new target

[Yousong Zhou]

On 7 December 2016 at 21:35, Felix Fietkau <nbd at nbd.name> wrote:
> On 2016-12-07 03:02, Yousong Zhou wrote:
>> An ARM Cortex-A15 machine provided by QEMU.
>>
>> Kernel drivers enabled:
>>
>>  - pl011, uart
>>  - pl031, rtc
>>  - pl061, gpio
>>  - pci-host-generic
>>  - virtio_{mmio,pci,net,blk,scsi,9p,console,balloon}
>>  - smp with NR_CPUS=4
>>  - cpu-hotplug
>>  - ext4
>>  - neon, vfp extensions support (otherwise userland will fail with
>>    illegal instruction signal (code 0x00000004))
>>  - DEBUG_BUGVERBOSE for debug purposes
>>
>> Signed-off-by: Yousong Zhou <yszhou4tech at gmail.com>
> Instead of ext4, I would recommend using squashfs images, like on x86 or
> uml.
>
> - Felix
>


Squashfs makes sense for a target for test purposes and I guess can
also be potentially useful in real-world as a read-only rootfs
solution.

However, the preliminary test showed that mksquashfs4 with option
"-bcj arm" will output unusable image (with high probabilities).  I
guess this is going to take a while to debug...

[    0.614270] VFS: Mounted root (squashfs filesystem) readonly on device 254:0.
[    0.625761] Freeing unused kernel memory: 220K (c048f000 - c04c6000)
[    0.650992] SQUASHFS error: xz decompression failed, data probably corrupt
[    0.651442] SQUASHFS error: squashfs_read_data failed to read block 0x28f7e
[    0.651649] SQUASHFS error: Unable to read fragment cache entry [28f7e]
[    0.651905] SQUASHFS error: Unable to read page, block 28f7e, size 142d0
[    0.652452] SQUASHFS error: Unable to read fragment cache entry [28f7e]
[    0.652636] SQUASHFS error: Unable to read page, block 28f7e, size 142d0
[    0.654612] Starting init: /etc/preinit exists but couldn't execute
it (error -5)

The complete command line just for the record

/home/yousong/git-repo/lede/staging_dir/host/bin/mksquashfs4
$PWD/root-armvirt o.squashfs -nopad -noappend -root-owned -comp xz
-Xpreset 9 -Xe -Xlc 0 -Xlp 2 -Xpb 2 -Xbcj arm -b 256k -p '/dev d 755 0
0' -p '/dev/console c 600 0 0 5 1' -processors 1 -fixed-time
1481075796

                yousong