On Mon, Aug 26, 2013 at 04:02:50PM +0800, TigerLiu@viatech.com.cn wrote:

Hi, experts:

I am studying bootm procedure.

In common/image.c, boot_get_fdt() function will parse IH_TYPE_MULTI format image.

But i could not find any doc describing legacy multi-component image format!

Could anybody provide me a doc?

Thanks a lot!

So, there's no specific documentation for it as it's described by the help on mkimage. But a real life example (since I dug one up in the past) is: $ mkimage -A arm -O linux -T multi -C none -a 80008000 -e 80008000 -n am335x-multi -d /tftpboot/v3.11.0-rc5/zImage:/tftpboot/ramdisk-pm.gz:/tftpboot/v3.11.0-rc5/am335x-bone.dtb /tftpboot/v3.11.0-rc5/uImage-multi

Which will create /tftboot/v3.11.0-rc5/uImage-multi with a zImage, ramdisk and single DT file. Now note! While with a just kernel image you can load it anywhere in memory and a bad overlap between load and entry point will be overlooked (we can move thigns around safely), with a multi-part you'll see: WARNING: legacy format multi component image overwritten And then likely failure. So you need to load things well out of the way.