Re: [Xen-devel] [PATCH 6/6] x86/boot: Ensure the BSS is aligned on an 8 byte boundary

At 16:34 +0100 on 09 Apr (1428597298), Andrew Cooper wrote: > On 09/04/15 16:15, Tim Deegan wrote: > > At 18:26 +0100 on 07 Apr (1428431180), Andrew Cooper wrote: > >> --- a/xen/arch/x86/boot/head.S > >> +++ b/xen/arch/x86/boot/head.S > >> @@ -127,7 +127,8 @@ __start: > >> mov $sym_phy

Re: [Xen-devel] [PATCH 6/6] x86/boot: Ensure the BSS is aligned on an 8 byte boundary

On 09/04/15 16:15, Tim Deegan wrote: > At 18:26 +0100 on 07 Apr (1428431180), Andrew Cooper wrote: >> --- a/xen/arch/x86/boot/head.S >> +++ b/xen/arch/x86/boot/head.S >> @@ -127,7 +127,8 @@ __start: >> mov $sym_phys(__bss_end),%ecx >> sub %edi,%ecx >> xor %eax

Re: [Xen-devel] [PATCH 6/6] x86/boot: Ensure the BSS is aligned on an 8 byte boundary

At 18:26 +0100 on 07 Apr (1428431180), Andrew Cooper wrote: > --- a/xen/arch/x86/boot/head.S > +++ b/xen/arch/x86/boot/head.S > @@ -127,7 +127,8 @@ __start: > mov $sym_phys(__bss_end),%ecx > sub %edi,%ecx > xor %eax,%eax > -rep stosb > +shr

[Xen-devel] [PATCH 6/6] x86/boot: Ensure the BSS is aligned on an 8 byte boundary

... and zero it more efficiently. A diff of the resulting binaries shows that the size of the BSS doesn't actually change from the extra ALIGN()s, but they do guarantee that it is safe to clear in an more efficient manner than 1 byte at a time. Signed-off-by: Andrew Cooper CC: Keir Fraser CC: J