Dear Danny, In message <52e15bad.1020...@coloradoengineeringinc.com> you wrote: > > > Yes - if you add support for 64 bit configurations in general, and > > for powerpc64 in particular. > I don't even have a sense for what would be involved here. How > fundamentally would the U-Boot code need to change?
It's probably heavy. There is a ton of places where we assume we can put an address in a "long" data type, etc. > My reason for wanting to run 64-bit is that this system has 12 GB of > RAM. Will 32-bit U-Boot be able to access and test more than 4 GB of RAM? No. For the "access" part: usually this i not really needed. U-Boot is a boot loader, intended to load and start an OS. for this, a 32 bit address space should be more than sufficient. For the "test" part, it is probably much easier to add a customized memory test (or fix just the existing memory test such that it can be built for a 64 bit mode) and use this, then trying to run all of U-Boot in 64 bit mode. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de "No matter where you go, there you are..." - Buckaroo Banzai _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
