qemu/pc-bios/s390-ccw/start.S
Christian Borntraeger bdc7fe3638 s390-ccw.img: Consume service interrupts
We have to consume the outstanding service interrupt after each
service call, otherwise a correct implementation will return
CC=2 on subsequent service calls.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2015-06-30 09:34:58 +02:00

66 lines
1.6 KiB
ArmAsm

/*
* First stage boot loader for virtio devices. The compiled output goes
* into the pc-bios directory of qemu.
*
* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
* Copyright 2013 IBM Corp.
*
* 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
* directory.
*/
.globl _start
_start:
larl %r15, stack + 0x8000 /* Set up stack */
larl %r6, boot_value
stg %r7, 0(%r6) /* save the boot_value before any function calls */
j main /* And call C */
/*
* void disabled_wait(void)
*
* stops the current guest cpu.
*/
.globl disabled_wait
disabled_wait:
larl %r1,disabled_wait_psw
lpswe 0(%r1)
/*
* void consume_sclp_int(void)
*
* eats one sclp interrupt
*/
.globl consume_sclp_int
consume_sclp_int:
/* enable service interrupts in cr0 */
stctg 0,0,0(15)
oi 6(15), 0x2
lctlg 0,0,0(15)
/* prepare external call handler */
larl %r1, external_new_code
stg %r1, 0x1b8
larl %r1, external_new_mask
mvc 0x1b0(8),0(%r1)
/* load enabled wait PSW */
larl %r1, enabled_wait_psw
lpswe 0(%r1)
external_new_code:
/* disable service interrupts in cr0 */
stctg 0,0,0(15)
ni 6(15), 0xfd
lctlg 0,0,0(15)
br 14
.align 8
disabled_wait_psw:
.quad 0x0002000180000000,0x0000000000000000
enabled_wait_psw:
.quad 0x0302000180000000,0x0000000000000000
external_new_mask:
.quad 0x0000000180000000