qemu/pc-bios/s390-ccw/start.S
Alexander Yarygin d046c51dad pc-bios/s390-ccw: Get device address via diag 308/6
To IPL from a device, pc-bios receives from qemu a device address via
general register 7. The better way to do it is to use diag308/6
instruction which returns so called
"IplParameterBlock". IplParameterBlock contains the device address for
IPL and additional parameters that can be used by pc-bios.

This patch allows pc-bios to get device address via diag308/6 and
doesn't use gr7 passed boot information anymore.

Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-05-17 15:50:29 +02:00

64 lines
1.5 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 */
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