LXR qemu/pc-bios/s390-ccw/start.S

   1/*
   2 * First stage boot loader for virtio devices. The compiled output goes
   3 * into the pc-bios directory of qemu.
   4 *
   5 * Copyright (c) 2013 Alexander Graf <agraf@suse.de>
   6 * Copyright 2013 IBM Corp.
   7 *
   8 * This work is licensed under the terms of the GNU GPL, version 2 or (at
   9 * your option) any later version. See the COPYING file in the top-level
  10 * directory.
  11 */
  12
  13        .globl _start
  14_start:
  15
  16larl    %r15, stack + 0x8000    /* Set up stack */
  17j       main                    /* And call C */
  18
  19/*
  20 * void disabled_wait(void)
  21 *
  22 * stops the current guest cpu.
  23 */
  24        .globl disabled_wait
  25disabled_wait:
  26        larl %r1,disabled_wait_psw
  27        lpswe   0(%r1)
  28
  29
  30/*
  31 * void consume_sclp_int(void)
  32 *
  33 * eats one sclp interrupt
  34 */
  35        .globl consume_sclp_int
  36consume_sclp_int:
  37        /* enable service interrupts in cr0 */
  38        stctg 0,0,0(15)
  39        oi 6(15), 0x2
  40        lctlg 0,0,0(15)
  41        /* prepare external call handler */
  42        larl %r1, external_new_code
  43        stg %r1, 0x1b8
  44        larl %r1, external_new_mask
  45        mvc 0x1b0(8),0(%r1)
  46        /* load enabled wait PSW */
  47        larl %r1, enabled_wait_psw
  48        lpswe 0(%r1)
  49
  50external_new_code:
  51        /* disable service interrupts in cr0 */
  52        stctg 0,0,0(15)
  53        ni 6(15), 0xfd
  54        lctlg 0,0,0(15)
  55        br 14
  56
  57        .align  8
  58disabled_wait_psw:
  59        .quad   0x0002000180000000,0x0000000000000000
  60enabled_wait_psw:
  61        .quad   0x0302000180000000,0x0000000000000000
  62external_new_mask:
  63        .quad   0x0000000180000000
  64