问题
I'm working on creating file that I can load with -kernel option of qemu. I mostly mind here u-boot config file that I have found information should be placed somewhere in file. That file have to contain u-boot binary, freebsd kernel and RTOS to run ( so i can choose which kernel to load or do some experimental developement in loading 2 OS at same time - eg. FreeBSD is loaded by u-boot and then FreeBSD loads FreeRTOS on 2nd core - so called ASMP ). It seems there is no tools around to do that in automatic way ( I mean supporting multiple kernels in one flash file ). So I need to know how is u-boot flash file structured to make my own and pass it to qemu emulating am versatilepb.
qemu-system-arm -M versatilepb -m 128M -nographic -kernel myflashfile
回答1:
So the answer here depends in part on the board you are emulating with QEMU. Next, unfortunately the versatilepb has been dropped from mainline U-Boot some time ago (and being ARM926EJS it is not the ideal core for ASMP, you may wish to try vexpress a9 instead). Now, all of that said, you want -pflash to pass along a binary file you control the contents of as the parallel flash device used by the machine. And you lay that out however you like since you're still using -kernel u-boot.bin to boot the machine. You may however find it easier to use -tftp /some/dir and load the files via the network instead.
来源：https://stackoverflow.com/questions/37035025/what-is-a-structure-of-u-boot-flash-file-arm-versatile-pb