Hallo Herr Denk,

wd@denx.de wrote on Saturday, July 08, 2006 6:41 PM:

...

The high boot U-Boot could be used as a backup or rescue option if something goes wrong during an (low boot) U-Boot update. For this a secondary copy of U-Boot is stored at the end of the flash memory. Over jumper X30 on the STK52xx the desired boot option (low boot or high boot) could be selected.

Hint: the CPLD on the TQM5200 must be programmed with a software version supporting the high boot option!

a) Sehen Sie dafür tatsächlich Bedarf?

The primary intention of the high-boot option is to provide a fall back boot option during the development phase of new baseboards for the TQM5200 module, or while playing around with U-Boot on the STK52xx evaluation board.

We see no advantage in using the high-boot option for series production, so the "normal" low-boot option remains the preferred way booting a TQM5200.

b) Wie kann der Kunde feststellen, ob der CPLD-Code auf seinem Modul Highboot unterstützt?

The high-boot option is supported on all TQM5200S modules and on the new revisions of the TQM5200 modules with MPC5200B cpu (which will be released soon).

c) Wie kann der Kunde den CPLD-Code aktualisieren?

For customers it is not possible to update the CPLD code on TQM5200 modules.

...

Both U-Boot versions (low boot and high boot) are using the same environment stored in flash at address 0xFC080000.

Das kann ich nicht akzeptieren. Das würde bedeuten, daß der Flash völlig zerstückelt ist: Unten ein Stück frei, dann Environment, dann ein größeres Stück frei, dann U-Boot-Code, dann wieder frei. So eine Konfiguration ist nicht sinnvoll. Wenn schon Highboot, dann legen Sie bitte auch das Envrionment nach oben.

Since the high-boot U-Boot is intended to be used _additionally_ to the low-boot U-Boot (as fall back option), the flash is not fragmented by the environment in this case.

If there is real demand for using the hight-boot option in series production, we will add an auxiliary configuration with both U-Boot and environment stored at the end of flash (to avoid the pointed out flash fragmentation).

Attached an updated Version of the hight-boot patch. The new version removes one configuration, to make things simpler for the users.

Viele Grüße, Martin Krause