/*
* Copyright (c) 2000-2020 Apple Inc. All rights reserved.
*
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*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
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*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
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#include <architecture/i386/pio.h>
#include <i386/panic_notify.h>
#include <kern/assert.h>
#include <pexpert/pexpert.h>
#include <stdint.h>
/*
* An I/O port to issue a read from, in the event of a panic.
* Useful for triggering logic analyzers.
*/
static uint16_t panic_io_port = 0;
/*
* Similar to the panic_io_port, the pvpanic_io_port is used to notify
* interested parties (in this case the host/hypervisor), that a panic
* has occurred.
* Where it differs from panic_io_port is that it is written and read
* according to the pvpanic specification:
* https://raw.githubusercontent.com/qemu/qemu/master/docs/specs/pvpanic.txt
*/
static uint16_t pvpanic_io_port = 0;
void
panic_notify_init(void)
{
(void) PE_parse_boot_argn("panic_io_port", &panic_io_port, sizeof(panic_io_port));
/*
* XXX
* Defer reading the notifcation bit until panic time. This maintains
* backwards compatibility with Apple's QEMU. Once backwards
* compatibilty is no longer needed the check should be performed here
* before setting pvpanic_io_port.
*/
(void) PE_parse_boot_argn("pvpanic_io_port", &pvpanic_io_port, sizeof(pvpanic_io_port));
}
void
panic_notify(void)
{
if (panic_io_port != 0) {
(void) inb(panic_io_port);
}
if (pvpanic_io_port != 0 &&
(inb(pvpanic_io_port) & PVPANIC_NOTIFICATION_BIT) != 0) {
outb(pvpanic_io_port, PVPANIC_NOTIFICATION_BIT);
}
}