search for: 43202952

...0000000c 00000000 00000000 00000000 00000000 0000000d 00000000 00000000 00000000 00000000 80000000 80000008 00000000 00000000 00000000 -80000001 00000000 00000000 00000001 2c100000 +80000001 00000000 00000000 00000001 2c100800 80000002 20202020 6e492020 286c6574 58202952 80000003 286e6f65 43202952 45205550 36322d35 80000004 204c3035 20402030 30382e31 007a4847 Could this be enough difference to throw cpu-detection off? Struan >>> Martin >>> >>>> Struan >>>> >>>> On 03/03/2014 10:00, Martin Kletzander wrote: >>>>> On Fri...

...t. Since "syscall" is x86_64 instruction used > instead of i386's "int 0x80" (IIRC) it makes sense that it is missing > on 32-bit CPU (when the code is running in 32-bit mode). > >> 80000002 20202020 6e492020 286c6574 58202952 >> 80000003 286e6f65 43202952 45205550 36322d35 >> 80000004 204c3035 20402030 30382e31 007a4847 >> >> Could this be enough difference to throw cpu-detection off? >> > Even one bit is enough if that bit represents a flag which is not in > the CPU you are looking for (i.e. SandyBridge). > >...

...uot; is x86_64 instruction used > > instead of i386's "int 0x80" (IIRC) it makes sense that it is missing > > on 32-bit CPU (when the code is running in 32-bit mode). > > > >> 80000002 20202020 6e492020 286c6574 58202952 > >> 80000003 286e6f65 43202952 45205550 36322d35 > >> 80000004 204c3035 20402030 30382e31 007a4847 > >> > >> Could this be enough difference to throw cpu-detection off? > >> > > Even one bit is enough if that bit represents a flag which is not in > > the CPU you are looking for...

...first one it doesn't. Since "syscall" is x86_64 instruction used instead of i386's "int 0x80" (IIRC) it makes sense that it is missing on 32-bit CPU (when the code is running in 32-bit mode). > 80000002 20202020 6e492020 286c6574 58202952 > 80000003 286e6f65 43202952 45205550 36322d35 > 80000004 204c3035 20402030 30382e31 007a4847 > > Could this be enough difference to throw cpu-detection off? > Even one bit is enough if that bit represents a flag which is not in the CPU you are looking for (i.e. SandyBridge). I must admin I was too lazy to comp...

On 03/03/2014 10:44, Martin Kletzander wrote: > On Mon, Mar 03, 2014 at 10:30:11AM +0000, Struan Bartlett wrote: >> Hi Martin >> >> Thanks for your response. Here's the output of that grep: >> >> # grep ^flags /proc/cpuinfo | sort -u >> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca >> cmov pat pse36 clflush dts acpi mmx