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+/*
+ * 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