/* * 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 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 * directory. */ .globl _start _start: 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) * * 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 %c0,%c0,0(%r15) oi 6(%r15),0x2 lctlg %c0,%c0,0(%r15) /* 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 %c0,%c0,0(%r15) ni 6(%r15),0xfd lctlg %c0,%c0,0(%r15) br %r14 .align 8 disabled_wait_psw: .quad 0x0002000180000000,0x0000000000000000 enabled_wait_psw: .quad 0x0302000180000000,0x0000000000000000 external_new_mask: .quad 0x0000000180000000