Dear U-boot team I'm currently working on an embedded system that uses U-boot as a second step bootloader. I'm testing the booting time of the kernel with binary formats. Before I was able to flash the first level bootloader, the u-boot and the kernel (uImage) into the nand flash of the embedded system with the following command on u-boot: bootcmd=nand read.jffs2 0x22000000 0x200000 0xB00000; bootm 0x22000000
- I would like to know if the bootm command is actually loading the complete kernel to RAM or if it is loading only the required pages from flash.
- Also, please correct me if I'm wrong but from the description of the bootm command, it seemed to me as if the bootm command should be enough to actually start the kernel, nevertheless I encountered myself with needing to previously read the kernel from the flash, to later be able to boot it, why is that so?
- I have also tried an xipImage for the kernel, nevertheless once I use this binary format, uboot promts an error: can't get kernel image! I checked the tutorial available at your website http://www.denx.de/wiki/bin/view/DULG/ConfigureLinuxForXIP, and I confirmed that my linux configuration creates an xipImage (not a uImage as stated in the tutorial). Does u-boot supports kernel execution in place? and if so, does it only loads the necesary pages or does it fully loads the kernel from the nand flash.
Thanks for your attention Kind regards _________________________________________ Camilo Andres Roca Duarte Communication and Media Engineering Student Hochschule Offenburg