In message 479515A4.3080103@freescale.com you wrote:
Waht's the best way to get the U-Boot version string (the one returned by U-Boot cmd "version") from userspace? Arg passed to the kernel? U-Boot env variables and use fw_getenv?
U-Boot disappears when the kernel loads, so the only cross-platform option is to pass a command-line parameter to the kernel. Such a change would probably not be accepted into the mainline, however.
First, reading the kernel command line can be done in user space - no need to change the kernel to do that.
Second, using the command line is not the only way to access envrionment data. Assuming the environment is stored in flash (or similar), you can of course read (and write) it from Linux, too.
Best regards,
Wolfgang Denk