So, in looking into my question below a little further in the way that the U-Boot command "bootm" does it, I understand how I can retrieve the mkimage header (image_header_t) to get the file size a multi-boot image is compromised of.

From Linux, I can retrieve the header from the Flash image and use the image size info in it to determine everything I need - vmlinux.gz size, ramdisk.image.gz size and total size i-

total_size = vmlinux.gz size + ramdisk.image.gz size + sizeof(image_header_t)

----- Forwarded message from tguilliams@synergy.synergymicro.com -----

Sender: u-boot-users-admin@lists.sourceforge.net Message-ID: 20040217234810.GA3573@raptor.synergymicro.com User-Agent: Mutt/1.5.6i Date: Tue, 17 Feb 2004 15:48:10 -0800 From: tguilliams@synergy.synergymicro.com To: u-boot-users@lists.sourceforge.net Subject: [U-Boot-Users] mkimage file size extraction?

I'm trying to retrieve a U-Boot multi-image from a Linux MTD flash partition. I'm not sure, without knowing the file size of the image there, how to make sure I retrieve the image alone and not the entire partition.

My U-Boot question is -

Is there a way I can extract _just_ the data size from the U-Boot wrapper header info?

i.e.,

make[2]: Leaving directory `/home/tomg/eldk/eldk-sbs/0.2/work/linux/linuxsbs-2.4.20/arch/ppc/boot/images' ./utils/mkimage.wrapper -A ppc -O linux -T multi -C gzip -a 00000000 -e 00000000 \ -n 'Linux-2.4.20 w/ ramdisk' \ -d images/vmlinux.gz:images/ramdisk.image.gz images/vmlinux.initrd.UBoot Image Name: Linux-2.4.20 w/ ramdisk Created: Tue Feb 17 15:33:45 2004 Image Type: PowerPC Linux Multi-File Image (gzip compressed) Data Size: 4524955 Bytes = 4418.90 kB = 4.32 MB Load Address: 0x00000000 Entry Point: 0x00000000 Contents: Image 0: 823267 Bytes = 803 kB = 0 MB Image 1: 3701675 Bytes = 3614 kB = 3 MB

I'm thinking of some operations using "dd" to seek and copy the data size to a file or something.

If this is not possible, I will quickly try and write a Linux NVRAM driver for U-Boot environmentals so that I can set a variable to retain the file image size.

Any ideas are greatly appreciated.