On 18.12.18 10:54, David Hildenbrand wrote: > On 18.12.18 10:26, Janosch Frank wrote: > > s/s390x: Switch to z\/Arch if needed/s390x: Switch to z\/Arch/ > > As you dropped the condition before the switch > >> LPAR and z/VM start in esam mode depending on the hardware, so we need >> to switch to z/Arch and set 64 bit addressing. >> >> Under Qemu/KVM we already start out with both when being run with the >> Qemu --kernel argument or we lack 64 bit when booting from disk >> because of the initial psw specifying 31 bit for z/VM and lpar >> compatibility. >> >> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx> >> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> >> --- >> s390x/cstart64.S | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/s390x/cstart64.S b/s390x/cstart64.S >> index d382497..7886f35 100644 >> --- a/s390x/cstart64.S >> +++ b/s390x/cstart64.S >> @@ -20,9 +20,17 @@ >> * >> * For KVM and TCG kernel boot we are in 64 bit z/Arch mode. >> * When booting from disk the initial short psw is in 31 bit mode. >> + * When running under LPAR or z/VM, we might start in 31 bit and esam mode. >> */ >> .globl start >> start: >> + /* Switch to z/Architecture mode and 64-bit */ >> + slr %r0, %r0 # Set cpuid to zero >> + lhi %r1, 2 # mode 2 = esame >> + sigp %r1, %r0, 0x12 # sigp set arch > > Use the new define for set architecture here? Will do > >> + bras %r13,0f # Jump over zero area >> + .fill 16,4,0x0 # Zero area for lmh >> +0: lmh %r0,%r15,0(%r13) # Clear high-order half of gprs >> sam64 # Set addressing mode to 64 bit >> /* setup stack */ >> larl %r15, stackptr >> > >
Attachment:
signature.asc
Description: OpenPGP digital signature
