On Tue, Jun 21, 2011 at 9:22 AM, Tony Lindgren <tony@xxxxxxxxxxx> wrote: > * Daniel Mack <zonque@xxxxxxxxx> [110617 18:06]: >> On Fri, Jun 17, 2011 at 4:03 PM, Gadiyar, Anand <gadiyar@xxxxxx> wrote: >> >> console=ttyS2,115200 root=/dev/mmcblk0p2 rw rootfstype=ext3 rootwait >> > >> > Here is your problem. We now use the OMAP-serial driver for the UARTs. >> >> Which breaks backward-compatibility with bootloaders set up for older >> kernels. Now I have to deploy kernels with CONFIG_CMDLINE_FORCE=y. Was >> that really necessary? > > In most cases you can just setenv cmdline then saveenv in u-boot. Well, it doesn't really affect me as I just use this as a development platform for now. But please consider that there is hardware out there which gets software updates through automated download and install procedures. In such cases, you want as little dependencies between the bootloader and the kernel, so you can boot both older and newer kernels (and full software distribution images) with no pain. Or maybe quickly switch from one version to the other for testing. Depending on the complexity of the system, the bootloader might also add extra parameters to the cmdline dynamically. The serial console change breaks this approach, at it forces the kernel to ship its own CMDLINE and override the one the bootloader provides. I'm sure this is a problem that affects people out there. Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
