1/* $OpenBSD: pagezero.S,v 1.2 2021/05/12 01:20:52 jsg Exp $ */ 2 3/* 4 * Copyright (c) 2020 Brian Bamsch <bbamsch@google.com> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19#include <machine/asm.h> 20#include <machine/param.h> 21 22#include "assym.h" 23 24ENTRY(pagezero) 25 RETGUARD_SETUP(pagezero, t6) 26 li a1, PAGE_SIZE 27 add a1, a0, a1 28 291: sd x0, 0(a0) 30 sd x0, 8(a0) 31 sd x0, 16(a0) 32 sd x0, 24(a0) 33 sd x0, 32(a0) 34 sd x0, 40(a0) 35 sd x0, 48(a0) 36 sd x0, 56(a0) 37 addi a0, a0, 64 38 blt a0, a1, 1b 39 40 RETGUARD_CHECK(pagezero, t6) 41 ret 42END(pagezero) 43