diff options
Diffstat (limited to 'pc-bios/s390-ccw/start.S')
| -rw-r--r-- | pc-bios/s390-ccw/start.S | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/pc-bios/s390-ccw/start.S b/pc-bios/s390-ccw/start.S index 43f9bd243e..eb8d024dbb 100644 --- a/pc-bios/s390-ccw/start.S +++ b/pc-bios/s390-ccw/start.S @@ -3,7 +3,7 @@ * into the pc-bios directory of qemu. * * Copyright (c) 2013 Alexander Graf <agraf@suse.de> - * Copyright 2013 IBM Corp. + * Copyright IBM Corp. 2013, 2017 * * This work is licensed under the terms of the GNU GPL, version 2 or (at * your option) any later version. See the COPYING file in the top-level @@ -13,8 +13,32 @@ .globl _start _start: -larl %r15, stack + 0x8000 /* Set up stack */ -j main /* And call C */ + larl %r15, stack + 0x8000 /* Set up stack */ + + /* clear bss */ + larl %r2, __bss_start + larl %r3, _end + slgr %r3, %r2 /* get sizeof bss */ + ltgr %r3,%r3 /* bss emtpy? */ + jz done + aghi %r3,-1 + srlg %r4,%r3,8 /* how many 256 byte chunks? */ + ltgr %r4,%r4 + lgr %r1,%r2 + jz remainder +loop: + xc 0(256,%r1),0(%r1) + la %r1,256(%r1) + brctg %r4,loop +remainder: + larl %r2,memsetxc + ex %r3,0(%r2) +done: + j main /* And call C */ + +memsetxc: + xc 0(1,%r1),0(%r1) + /* * void disabled_wait(void) |