4f0e427025
This doesn’t work on the Raspberry Pi yet (due to missing kexec_file_load), but I tested it in qemu.
66 lines
1.5 KiB
Go
66 lines
1.5 KiB
Go
package gokrazy
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import (
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"io/ioutil"
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"log"
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"os"
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"path/filepath"
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"syscall"
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"unsafe"
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"golang.org/x/sys/unix"
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)
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// TODO: get these constants into sys/unix
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const (
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KEXEC_ARCH_DEFAULT = (0 << 16)
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KEXEC_FILE_NO_INITRAMFS = 0x00000004
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)
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func kexecReboot() error {
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tmpdir, err := ioutil.TempDir("", "kexec")
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if err != nil {
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return err
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}
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if err := syscall.Mount(mustFindRootDevice()+"1", tmpdir, "vfat", 0, ""); err != nil {
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return err
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}
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kernel, err := os.Open(filepath.Join(tmpdir, "vmlinuz"))
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if err != nil {
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return err
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}
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defer kernel.Close()
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cmdline, err := ioutil.ReadFile("/proc/cmdline")
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if err != nil {
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return err
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}
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rep := rootRe.ReplaceAllLiteral(cmdline, []byte("root="+mustFindRootDevice()+inactiveRootPartition))
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// NUL-terminate cmdline
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cmdlinebuf := make([]byte, len(rep)+1)
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copy(cmdlinebuf, rep)
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_, _, errno := unix.Syscall6(
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unix.SYS_KEXEC_FILE_LOAD,
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uintptr(kernel.Fd()), // kernel_fd
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0, // initrd_fd
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uintptr(len(cmdline)+1), // cmdline_len
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uintptr(unsafe.Pointer(&cmdlinebuf[0])), // cmdline
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KEXEC_ARCH_DEFAULT|KEXEC_FILE_NO_INITRAMFS, // flags
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0)
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if errno != 0 {
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// errno is syscall.ENOSYS on kernels without CONFIG_KEXEC_FILE_LOAD=y
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return errno
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}
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return unix.Reboot(unix.LINUX_REBOOT_CMD_KEXEC)
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}
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func reboot() error {
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if err := kexecReboot(); err != nil {
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log.Printf("kexec reboot failed: %v", err)
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return unix.Reboot(unix.LINUX_REBOOT_CMD_RESTART)
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}
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return nil
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}
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