On 08/27/14 20:09, Peter Maydell wrote: > On 27 August 2014 17:58, Ard Biesheuvel <[email protected]> wrote: >> On 27 August 2014 18:03, Laszlo Ersek <[email protected]> wrote: >>> - Why require a 64MB flash drive, if we only use 768 KB of it? >>> >> >> The ARM Versatile Express development hardware is set up like this, >> that is the whole and only reason. >> I guess we could change it if there is a strong reason to do so, but >> parity with the other emulated machines makes the maintenance job a >> bit easier, I imagine. > > Yeah, this isn't a strong requirement from the QEMU side, but > the thought process went something like: > * two flash devices is better than one, so we can allow a split > between what kind of backing file they get (treating ROM > image differently than non-volatile storage)
ACK for that, positively > * might as well be reasonably generous with the sizing, to > allow for future expansion in what software uses > * having an asymmetric "one small, one large" setup seems > kind of weird > * UEFI isn't necessarily the only user of this board model Okay. Thanks! > If we've done something silly with the way we've instantiated > the flash device in QEMU that means it has a stupid large > block size then we might be able to fix that. The old wisdom says "measure it first" :) I think this should only matter on KVM, if it matters at all. And one way to measure it (if someone really cares) would be to run a Linux guest, and massage some non-volatile variables from there, in a loop. An example program is under <http://blog.fpmurphy.com/2012/12/efivars-and-efivarfs.html>. However I think this investigation can be postponed indefinitely (unless someone notices a perf degradation with the naked eye). The only thing that caught my eye was the block size being *different* from OVMF's and "hw/i386/pc_sysfw.c"'s, but that isn't necessarily a problem. I think this patch is fine unless proven otherwise in practice. Thanks, Laszlo ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ _______________________________________________ edk2-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/edk2-devel
