On Mon, Feb 15, 2016 at 01:07:09AM +0000, Michael Brown wrote: > On 14/02/16 19:52, Michael S. Tsirkin wrote: > >On Sun, Feb 14, 2016 at 05:36:38PM +0000, Michael Brown wrote: > >>On 14/02/16 15:53, Michael S. Tsirkin wrote: > >>>do you think %DS should be zeroed when NBP is called then? > >> > >>Not according to the PXE spec. > >> > >>As far as I can tell, the initial value of %ds is undefined for both a PXE > >>NBP and a BIOS boot sector. > > > >Thanks, > > Out of interest: did this question arise as a purely academic curiosity, or > is there some product in existence which creates a boot sector that relies > on %ds==0? > > Michael
FWIW QEMU has a unit test with a boot sector that relies on %ds=0: https://git.kernel.org/cgit/virt/kvm/mst/qemu.git/tree/tests/bios-tables-test.c?h=pci (search for boot_sector in this file). It's a test, not a product though, and would be easy to change not to rely on this. -- MST _______________________________________________ ipxe-devel mailing list ipxe-devel@lists.ipxe.org https://lists.ipxe.org/mailman/listinfo.cgi/ipxe-devel
