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/*
* S390 virtio-ccw network boot loading program
*
* Copyright 2017 Thomas Huth, Red Hat Inc.
*
* Based on the S390 virtio-ccw loading program (main.c)
* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include "s390-ccw.h"
#include "virtio.h"
extern char _start[];
char stack[PAGE_SIZE * 8] __attribute__((aligned(PAGE_SIZE)));
IplParameterBlock iplb __attribute__((aligned(PAGE_SIZE)));
static SubChannelId net_schid = { .one = 1 };
static uint64_t dest_timer;
static uint64_t get_timer_ms(void)
{
uint64_t clk;
asm volatile(" stck %0 " : : "Q"(clk) : "memory");
/* Bit 51 is incremented each microsecond */
return (clk >> (63 - 51)) / 1000;
}
void set_timer(int val)
{
dest_timer = get_timer_ms() + val;
}
int get_timer(void)
{
return dest_timer - get_timer_ms();
}
int get_sec_ticks(void)
{
return 1000; /* number of ticks in 1 second */
}
void panic(const char *string)
{
sclp_print(string);
for (;;) {
disabled_wait();
}
}
static bool find_net_dev(Schib *schib, int dev_no)
{
int i, r;
for (i = 0; i < 0x10000; i++) {
net_schid.sch_no = i;
r = stsch_err(net_schid, schib);
if (r == 3 || r == -EIO) {
break;
}
if (!schib->pmcw.dnv) {
continue;
}
if (!virtio_is_supported(net_schid)) {
continue;
}
if (virtio_get_device_type() != VIRTIO_ID_NET) {
continue;
}
if (dev_no < 0 || schib->pmcw.dev == dev_no) {
return true;
}
}
return false;
}
static void virtio_setup(void)
{
Schib schib;
int ssid;
bool found = false;
uint16_t dev_no;
/*
* We unconditionally enable mss support. In every sane configuration,
* this will succeed; and even if it doesn't, stsch_err() can deal
* with the consequences.
*/
enable_mss_facility();
if (store_iplb(&iplb)) {
IPL_assert(iplb.pbt == S390_IPL_TYPE_CCW, "IPL_TYPE_CCW expected");
dev_no = iplb.ccw.devno;
debug_print_int("device no. ", dev_no);
net_schid.ssid = iplb.ccw.ssid & 0x3;
debug_print_int("ssid ", net_schid.ssid);
found = find_net_dev(&schib, dev_no);
} else {
for (ssid = 0; ssid < 0x3; ssid++) {
net_schid.ssid = ssid;
found = find_net_dev(&schib, -1);
if (found) {
break;
}
}
}
IPL_assert(found, "No virtio net device found");
}
void main(void)
{
sclp_setup();
sclp_print("Network boot starting...\n");
virtio_setup();
panic("Failed to load OS from network\n");
}
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