From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Michael Chang <mchang@suse.com>

Date: Tue, 6 Feb 2018 09:09:00 +0100

Subject: [PATCH] Add linux and initrd commands for grub-emu

When using grub-emu, the linux and initrd commands are used as arguments

to the kexec command line tool, to allow booting the selected menu entry.

---

 grub-core/Makefile.core.def  |   1 -

 grub-core/kern/emu/main.c    |   4 +

 grub-core/kern/emu/misc.c    |  18 ++++-

 grub-core/loader/emu/linux.c | 172 +++++++++++++++++++++++++++++++++++++++++++

 include/grub/emu/exec.h      |   4 +-

 include/grub/emu/hostfile.h  |   3 +-

 include/grub/emu/misc.h      |   3 +

 grub-core/Makefile.am        |   1 +

 8 files changed, 202 insertions(+), 4 deletions(-)

 create mode 100644 grub-core/loader/emu/linux.c

diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def

index e52d77688..067b97a42 100644

--- a/grub-core/Makefile.core.def

+++ b/grub-core/Makefile.core.def

@@ -1710,7 +1710,6 @@ module = {

   common = loader/linux.c;

   common = lib/cmdline.c;

-  enable = noemu;

   efi = loader/efi/linux.c;

 };

diff --git a/grub-core/kern/emu/main.c b/grub-core/kern/emu/main.c

index 55ea5a11c..846fe9715 100644

--- a/grub-core/kern/emu/main.c

+++ b/grub-core/kern/emu/main.c

@@ -107,6 +107,7 @@ static struct argp_option options[] = {

    N_("use GRUB files in the directory DIR [default=%s]"), 0},

   {"verbose",     'v', 0,      0, N_("print verbose messages."), 0},

   {"hold",     'H', N_("SECS"),      OPTION_ARG_OPTIONAL, N_("wait until a debugger will attach"), 0},

+  {"kexec",       'X', 0,      0, N_("try the untryable."), 0},

   { 0, 0, 0, 0, 0, 0 }

 };

@@ -164,6 +165,9 @@ argp_parser (int key, char *arg, struct argp_state *state)

     case 'v':

       verbosity++;

       break;

+    case 'X':

+      grub_util_set_kexecute();

+      break;

     case ARGP_KEY_ARG:

       {

diff --git a/grub-core/kern/emu/misc.c b/grub-core/kern/emu/misc.c

index 82012a72f..3d3a4a4a9 100644

--- a/grub-core/kern/emu/misc.c

+++ b/grub-core/kern/emu/misc.c

@@ -37,6 +37,7 @@

 #include <grub/emu/misc.h>

 int verbosity;

+int kexecute;

 void

 grub_util_warn (const char *fmt, ...)

@@ -80,7 +81,7 @@ grub_util_error (const char *fmt, ...)

   vfprintf (stderr, fmt, ap);

   va_end (ap);

   fprintf (stderr, ".\n");

-  exit (1);

+  grub_exit (1);

 }

 void *

@@ -140,6 +141,9 @@ void

 __attribute__ ((noreturn))

 grub_exit (int rc)

 {

+#if defined (GRUB_KERNEL)

+  grub_reboot();

+#endif

   exit (rc < 0 ? 1 : rc);

 }

 #endif

@@ -201,3 +205,15 @@ grub_util_load_image (const char *path, char *buf)

   fclose (fp);

 }

+

+void

+grub_util_set_kexecute(void)

+{

+  kexecute++;

+}

+

+int

+grub_util_get_kexecute(void)

+{

+  return kexecute;

+}

diff --git a/grub-core/loader/emu/linux.c b/grub-core/loader/emu/linux.c

new file mode 100644

index 000000000..fda9e00d2

--- /dev/null

+++ b/grub-core/loader/emu/linux.c

@@ -0,0 +1,172 @@

+/*

+ *  GRUB  --  GRand Unified Bootloader

+ *  Copyright (C) 2006,2007,2008,2009,2010  Free Software Foundation, Inc.

+ *

+ *  GRUB 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 3 of the License, or

+ *  (at your option) any later version.

+ *

+ *  GRUB is distributed in the hope that it will be useful,

+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of

+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+ *  GNU General Public License for more details.

+ *

+ *  You should have received a copy of the GNU General Public License

+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.

+ */

+

+#include <grub/loader.h>

+#include <grub/dl.h>

+#include <grub/command.h>

+#include <grub/time.h>

+

+#include <grub/emu/exec.h>

+#include <grub/emu/hostfile.h>

+#include <grub/emu/misc.h>

+

+GRUB_MOD_LICENSE ("GPLv3+");

+

+static grub_dl_t my_mod;

+

+static char *kernel_path;

+static char *initrd_path;

+static char *boot_cmdline;

+

+static grub_err_t

+grub_linux_boot (void)

+{

+  grub_err_t rc = GRUB_ERR_NONE;

+  char *initrd_param;

+  const char *kexec[] = { "kexec", "-l", kernel_path, boot_cmdline, NULL, NULL };

+  const char *systemctl[] = { "systemctl", "kexec", NULL };

+  int kexecute = grub_util_get_kexecute();

+

+  if (initrd_path) {

+    initrd_param = grub_xasprintf("--initrd=%s", initrd_path);

+    kexec[3] = initrd_param;

+    kexec[4] = boot_cmdline;

+  } else {

+    initrd_param = grub_xasprintf("%s", "");

+  }

+

+  grub_printf("%serforming 'kexec -l %s %s %s'\n",

+	(kexecute) ? "P" : "Not p",

+	kernel_path, initrd_param, boot_cmdline);

+

+  if (kexecute)

+    rc = grub_util_exec(kexec);

+

+  grub_free(initrd_param);

+

+  if (rc != GRUB_ERR_NONE) {

+    grub_error (rc, N_("Error trying to perform kexec load operation."));

+    grub_sleep (3);

+    return rc;

+  }

+  if (kexecute < 1)

+    grub_fatal (N_("Use '"PACKAGE"-emu --kexec' to force a system restart."));

+

+  grub_printf("Performing 'systemctl kexec' (%s) ",

+		(kexecute==1) ? "do-or-die" : "just-in-case");

+  rc = grub_util_exec (systemctl);

+

+  if (kexecute == 1)

+    grub_fatal (N_("Error trying to perform 'systemctl kexec'"));

+

+  /* need to check read-only root before resetting hard!? */

+  grub_printf("Performing 'kexec -e'");

+  kexec[1] = "-e";

+  kexec[2] = NULL;

+  rc = grub_util_exec(kexec);

+  if ( rc != GRUB_ERR_NONE )

+    grub_fatal (N_("Error trying to directly perform 'kexec -e'."));

+

+  return rc;

+}

+

+static grub_err_t

+grub_linux_unload (void)

+{

+  grub_dl_unref (my_mod);

+  if ( boot_cmdline != NULL )

+    grub_free (boot_cmdline);

+  boot_cmdline = NULL;

+  return GRUB_ERR_NONE;

+}

+

+static grub_err_t

+grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)), int argc, char *argv[])

+{

+  int i;

+  char *tempstr;

+

+  grub_dl_ref (my_mod);

+

+  if (argc == 0)

+    return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));

+

+  if ( !grub_util_is_regular(argv[0]) )

+    return grub_error(GRUB_ERR_FILE_NOT_FOUND, N_("Cannot find kernel file %s"), argv[0]);

+

+  if ( kernel_path != NULL )

+    grub_free(kernel_path);

+

+  kernel_path = grub_xasprintf("%s", argv[0]);

+

+  if ( boot_cmdline != NULL ) {

+    grub_free(boot_cmdline);

+    boot_cmdline = NULL;

+  }

+

+  if ( argc > 1 )

+  {

+    boot_cmdline = grub_xasprintf("--command-line=%s", argv[1]);

+    for ( i = 2; i < argc; i++ ) {

+      tempstr = grub_xasprintf("%s %s", boot_cmdline, argv[i]);

+      grub_free(boot_cmdline);

+      boot_cmdline = tempstr;

+    }

+  }

+

+  grub_loader_set (grub_linux_boot, grub_linux_unload, 0);

+

+  return GRUB_ERR_NONE;

+}

+

+static grub_err_t

+grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)), int argc, char *argv[])

+{

+  if (argc == 0)

+    return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));

+

+  if ( !grub_util_is_regular(argv[0]) )

+    return grub_error(GRUB_ERR_FILE_NOT_FOUND, N_("Cannot find initrd file %s"), argv[0]);

+

+  if ( initrd_path != NULL )

+    grub_free(initrd_path);

+

+  initrd_path = grub_xasprintf("%s", argv[0]);

+

+  grub_dl_unref (my_mod);

+

+  return GRUB_ERR_NONE;

+}

+

+static grub_command_t cmd_linux, cmd_initrd;

+

+GRUB_MOD_INIT(linux)

+{

+  cmd_linux = grub_register_command ("linux", grub_cmd_linux, 0, N_("Load Linux."));

+  cmd_initrd = grub_register_command ("initrd", grub_cmd_initrd, 0, N_("Load initrd."));

+  my_mod = mod;

+  kernel_path = NULL;

+  initrd_path = NULL;

+  boot_cmdline = NULL;

+}

+

+GRUB_MOD_FINI(linux)

+{

+  grub_unregister_command (cmd_linux);

+  grub_unregister_command (cmd_initrd);

+}

diff --git a/include/grub/emu/exec.h b/include/grub/emu/exec.h

index d1073ef86..1b61b4a2e 100644

--- a/include/grub/emu/exec.h

+++ b/include/grub/emu/exec.h

@@ -23,6 +23,8 @@

 #include <stdarg.h>

 #include <sys/types.h>

+#include <grub/symbol.h>

+

 pid_t

 grub_util_exec_pipe (const char *const *argv, int *fd);

 pid_t

@@ -32,7 +34,7 @@ int

 grub_util_exec_redirect_all (const char *const *argv, const char *stdin_file,

 			     const char *stdout_file, const char *stderr_file);

 int

-grub_util_exec (const char *const *argv);

+EXPORT_FUNC(grub_util_exec) (const char *const *argv);

 int

 grub_util_exec_redirect (const char *const *argv, const char *stdin_file,

 			 const char *stdout_file);

diff --git a/include/grub/emu/hostfile.h b/include/grub/emu/hostfile.h

index 8e37d5acb..12c937a1a 100644

--- a/include/grub/emu/hostfile.h

+++ b/include/grub/emu/hostfile.h

@@ -22,6 +22,7 @@

 #include <grub/disk.h>

 #include <grub/partition.h>

 #include <sys/types.h>

+#include <grub/symbol.h>

 #include <grub/osdep/hostfile.h>

 int

@@ -29,7 +30,7 @@ grub_util_is_directory (const char *path);

 int

 grub_util_is_special_file (const char *path);

 int

-grub_util_is_regular (const char *path);

+EXPORT_FUNC(grub_util_is_regular) (const char *path);

 char *

 grub_util_path_concat (size_t n, ...);

diff --git a/include/grub/emu/misc.h b/include/grub/emu/misc.h

index df6085bcb..a653132e3 100644

--- a/include/grub/emu/misc.h

+++ b/include/grub/emu/misc.h

@@ -60,6 +60,9 @@ void EXPORT_FUNC(grub_util_warn) (const char *fmt, ...) __attribute__ ((format (

 void EXPORT_FUNC(grub_util_info) (const char *fmt, ...) __attribute__ ((format (__printf__, 1, 2)));

 void EXPORT_FUNC(grub_util_error) (const char *fmt, ...) __attribute__ ((format (__printf__, 1, 2), noreturn));

+void EXPORT_FUNC(grub_util_set_kexecute) (void);

+int EXPORT_FUNC(grub_util_get_kexecute) (void) WARN_UNUSED_RESULT;

+

 grub_uint64_t EXPORT_FUNC (grub_util_get_cpu_time_ms) (void);

 #ifdef HAVE_DEVICE_MAPPER

diff --git a/grub-core/Makefile.am b/grub-core/Makefile.am

index 9c69aa886..0108c0d42 100644

--- a/grub-core/Makefile.am

+++ b/grub-core/Makefile.am

@@ -274,6 +274,7 @@ KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/emu/net.h

 KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/emu/hostdisk.h

 KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/emu/hostfile.h

 KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/extcmd.h

+KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/emu/exec.h

 if COND_GRUB_EMU_SDL

 KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/sdl.h

 endif