On Tue, 3 Jun 2003 23:47:22 -0700 Darin.Johnson at nokia.com wrote: > It also could be very nice if you could upgrade the lowest level of software, > the boot loader or system initializer (ppcboot, etc). We had found a bug in > our loader at one point, and because many registers are "write once" it was > difficult to fix these settings from the application software. But finding a > foolproof and reliable way to upgrade the boot loader software is difficult, > especially if you are relying on customers and operators to do the upgrading.
And that's why you should use Miniboot as your first bootloader. =) It's not upgradeable itself, but it is used to load and update a secondary bootloader. Miniboot itself should be very small and simple to keep the number of bugs low. It only requires the internal memory of the mpc8xx so almost all hardware initialization is made after miniboot has run, and therefore is upgradeable. Need to upgrade your hardware configuration? No problem as long as you haven't changed CS0 or your SMC... =) And yes, it runs with watchdog on and leaves that configuration up to the secondary bootloader. http://opensource.se/projects/miniboot/index.html However, the number of boards / processors supported are limited at the moment. I've also heard that uboot/ppcboot could be used to update itself, but I've never tested it myself. / magnus ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
