[yocto] How to extract files from wic.gz image?

[JH]

Thanks Zoran and Tom, I can use dd to install the image to SD card on
IMX EVK, now I need to install the image to NAND flash of a customized
IMX device via USB HID, it cannot use the dd, IMX provided UUU utility
which I am new to it and I have to decompose the image to
zImage-initramfs and  losetup -P does work, dd does not work either.

$ losetup -P dev-image-20190528085324.rootfs.wic
losetup: solar-dev-image-solarevk-20190518084330.rootfs.wic: failed to
use device: No such device

Thanks for your helps anyway.

Kind regards,

- jupiter

On 5/31/19, Tom Rini <trini at konsulko.com> wrote:
> On Fri, May 31, 2019 at 10:21:40PM +1000, JH wrote:
>> Hi,
>>
>> What command and tools to extract files from Yocto / bitbake image
>> such as dev-image-20190528085324.rootfs.wic.gz?
>>
>> I am using IMX UUU to install dev-image-20190528085324.rootfs.wic.gz
>> to IMX, I was advised to extract the archive and use "uuu <script
>> name>" or "uuu u-boot-dtb.imx" to get bootloader work first.
>
> A wic image is just another way of saying it's a raw disk image.
> Decompress it, losetup -P (generally useful, but not needed this time)
> and dd out the contents you want.
>
> --
> Tom
>