android_packages_modules_Vi.../microdroid/kdump/kexec.c

60 lines
1.9 KiB
C

/*
* Copyright (C) 2022 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// This program loads kernel and initrd which the system will boot into when
// panic occurs.
#include <errno.h>
#include <fcntl.h>
#include <linux/kexec.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
#if defined(__aarch64__)
#define EARLYCON "earlycon=uart8250,mmio,0x3f8"
#elif defined(__x86_64__)
#define EARLYCON "earlycon=uart8250,io,0x3f8"
#endif
static const char *KERNEL = "/system/etc/microdroid_crashdump_kernel";
static const char *INITRD = "/system/etc/microdroid_crashdump_initrd.img";
static const char *CMDLINE = "1 panic=-1 rdinit=/bin/crashdump nr_cpus=1 reset_devices "
"console=hvc0 " EARLYCON;
static int open_checked(const char* path) {
int fd = open(path, O_RDONLY);
if (fd == -1) {
fprintf(stderr, "Failed to open %s: %s\n", path, strerror(errno));
exit(1);
}
return fd;
}
int main() {
unsigned long cmdline_len = strlen(CMDLINE) + 1; // include null terminator, otherwise EINVAL
if (syscall(SYS_kexec_file_load, open_checked(KERNEL), open_checked(INITRD), cmdline_len,
CMDLINE, KEXEC_FILE_ON_CRASH) == -1) {
fprintf(stderr, "Failed to load panic kernel: %s\n", strerror(errno));
return 1;
}
return 0;
}