[PATCH] [RFC] Add exitcode support

[dann frazier]

Some platforms are capable of changing behavior based on the bootloader
exit code. In particular, UEFI boot managers use this code to determine
if they should try the next boot entry or not. I'd like to use this as
a way to make my PXE server tell clients to attempt to boot from their
next entry (presumably an on-disk OS), providing something akin to
pxelinux's "localboot".

The implementation here is to add a new optional argument to the exit
command. The platform-specific grub_exit() implementations can then
translate it into a platform-appropriate exit code.

Signed-off-by: dann frazier <address@hidden>
---
 grub-core/commands/minicmd.c         | 12 ++++++++----
 grub-core/kern/efi/efi.c             | 20 ++++++++++++++++++--
 grub-core/kern/emu/misc.c            |  3 ++-
 grub-core/kern/i386/coreboot/init.c  |  3 ++-
 grub-core/kern/i386/qemu/init.c      |  3 ++-
 grub-core/kern/ieee1275/init.c       |  3 ++-
 grub-core/kern/mips/arc/init.c       |  3 ++-
 grub-core/kern/mips/loongson/init.c  |  3 ++-
 grub-core/kern/mips/qemu_mips/init.c |  3 ++-
 grub-core/kern/misc.c                |  3 ++-
 grub-core/kern/uboot/init.c          |  5 +++--
 grub-core/kern/xen/init.c            |  2 +-
 include/grub/exitcode.h              | 30 ++++++++++++++++++++++++++++++
 include/grub/misc.h                  |  3 ++-
 14 files changed, 78 insertions(+), 18 deletions(-)
 create mode 100644 include/grub/exitcode.h

diff --git a/grub-core/commands/minicmd.c b/grub-core/commands/minicmd.c
index a3a1182..d67cdf1 100644
--- a/grub-core/commands/minicmd.c
+++ b/grub-core/commands/minicmd.c
@@ -28,6 +28,7 @@
 #include <grub/loader.h>
 #include <grub/command.h>
 #include <grub/i18n.h>
+#include <grub/exitcode.h>
 
 GRUB_MOD_LICENSE ("GPLv3+");
 
@@ -178,10 +179,13 @@ grub_mini_cmd_lsmod (struct grub_command *cmd 
__attribute__ ((unused)),
 /* exit */
 static grub_err_t __attribute__ ((noreturn))
 grub_mini_cmd_exit (struct grub_command *cmd __attribute__ ((unused)),
-                   int argc __attribute__ ((unused)),
-                   char *argv[] __attribute__ ((unused)))
+                   int argc, char *argv[])
+
 {
-  grub_exit ();
+  grub_exitcode_t exitcode;
+
+  exitcode = argc ? grub_strtoul(argv[0], 0, 10) : GRUB_EXITCODE_NONE;
+  grub_exit (exitcode);
   /* Not reached.  */
 }
 
@@ -207,7 +211,7 @@ GRUB_MOD_INIT(minicmd)
                           0, N_("Show loaded modules."));
   cmd_exit =
     grub_register_command ("exit", grub_mini_cmd_exit,
-                          0, N_("Exit from GRUB."));
+                          N_("[EXITCODE]"), N_("Exit from GRUB."));
 }
 
 GRUB_MOD_FINI(minicmd)
diff --git a/grub-core/kern/efi/efi.c b/grub-core/kern/efi/efi.c
index caf9bcc..33fb737 100644
--- a/grub-core/kern/efi/efi.c
+++ b/grub-core/kern/efi/efi.c
@@ -28,6 +28,7 @@
 #include <grub/kernel.h>
 #include <grub/mm.h>
 #include <grub/loader.h>
+#include <grub/exitcode.h>
 
 /* The handle of GRUB itself. Filled in by the startup code.  */
 grub_efi_handle_t grub_efi_image_handle;
@@ -155,11 +156,26 @@ grub_efi_get_loaded_image (grub_efi_handle_t image_handle)
 }
 
 void
-grub_exit (void)
+grub_exit (grub_exitcode_t exitcode)
 {
+  grub_efi_status_t efi_status;
+
   grub_machine_fini (GRUB_LOADER_FLAG_NORETURN);
+
+  /* Map the GRUB exitcode to a suitable EFI status */
+  switch (exitcode)
+    {
+    case GRUB_EXITCODE_NEXT:
+      /* Anything other than EFI_SUCCESS will do (UEFI 2.5 section 3.1.1) */
+      efi_status = GRUB_EFI_LOAD_ERROR;
+      break;
+    default:
+      efi_status = GRUB_EFI_SUCCESS;
+      break;
+    }
+
   efi_call_4 (grub_efi_system_table->boot_services->exit,
-              grub_efi_image_handle, GRUB_EFI_SUCCESS, 0, 0);
+              grub_efi_image_handle, efi_status, 0, 0);
   for (;;) ;
 }
 
diff --git a/grub-core/kern/emu/misc.c b/grub-core/kern/emu/misc.c
index bb606da..4f345d6 100644
--- a/grub-core/kern/emu/misc.c
+++ b/grub-core/kern/emu/misc.c
@@ -35,6 +35,7 @@
 #include <grub/i18n.h>
 #include <grub/time.h>
 #include <grub/emu/misc.h>
+#include <grub/exitcode.h>
 
 int verbosity;
 
@@ -135,7 +136,7 @@ xasprintf (const char *fmt, ...)
 #endif
 
 void
-grub_exit (void)
+grub_exit (grub_exitcode_t exitcode __attribute__ ((unused)))
 {
   exit (1);
 }
diff --git a/grub-core/kern/i386/coreboot/init.c 
b/grub-core/kern/i386/coreboot/init.c
index 3314f02..07294a1 100644
--- a/grub-core/kern/i386/coreboot/init.c
+++ b/grub-core/kern/i386/coreboot/init.c
@@ -35,13 +35,14 @@
 #include <grub/cpu/floppy.h>
 #include <grub/cpu/tsc.h>
 #include <grub/video.h>
+#include <grub/exitcode.h>
 
 extern grub_uint8_t _start[];
 extern grub_uint8_t _end[];
 extern grub_uint8_t _edata[];
 
 void  __attribute__ ((noreturn))
-grub_exit (void)
+grub_exit (grub_exitcode_t exitcode __attribute__ ((unused)))
 {
   /* We can't use grub_fatal() in this function.  This would create an infinite
      loop, since grub_fatal() calls grub_abort() which in turn calls 
grub_exit().  */
diff --git a/grub-core/kern/i386/qemu/init.c b/grub-core/kern/i386/qemu/init.c
index 271b6fb..67e155c 100644
--- a/grub-core/kern/i386/qemu/init.c
+++ b/grub-core/kern/i386/qemu/init.c
@@ -36,13 +36,14 @@
 #include <grub/cpu/tsc.h>
 #include <grub/machine/kernel.h>
 #include <grub/pci.h>
+#include <grub/exitcode.h>
 
 extern grub_uint8_t _start[];
 extern grub_uint8_t _end[];
 extern grub_uint8_t _edata[];
 
 void  __attribute__ ((noreturn))
-grub_exit (void)
+grub_exit (grub_exitcode_t exitcode __attribute__ ((unused)))
 {
   /* We can't use grub_fatal() in this function.  This would create an infinite
      loop, since grub_fatal() calls grub_abort() which in turn calls 
grub_exit().  */
diff --git a/grub-core/kern/ieee1275/init.c b/grub-core/kern/ieee1275/init.c
index d5bd74d..996663f 100644
--- a/grub-core/kern/ieee1275/init.c
+++ b/grub-core/kern/ieee1275/init.c
@@ -35,6 +35,7 @@
 #include <grub/offsets.h>
 #include <grub/memory.h>
 #include <grub/loader.h>
+#include <grub/exitcode.h>
 #ifdef __i386__
 #include <grub/cpu/tsc.h>
 #endif
@@ -60,7 +61,7 @@ grub_addr_t grub_ieee1275_original_stack;
 #endif
 
 void
-grub_exit (void)
+grub_exit (grub_exitcode_t exitcode __attribute__ ((unused)))
 {
   grub_ieee1275_exit ();
 }
diff --git a/grub-core/kern/mips/arc/init.c b/grub-core/kern/mips/arc/init.c
index 3834a14..28189b4 100644
--- a/grub-core/kern/mips/arc/init.c
+++ b/grub-core/kern/mips/arc/init.c
@@ -36,6 +36,7 @@
 #include <grub/i18n.h>
 #include <grub/disk.h>
 #include <grub/partition.h>
+#include <grub/exitcode.h>
 
 const char *type_names[] = {
 #ifdef GRUB_CPU_WORDS_BIGENDIAN
@@ -276,7 +277,7 @@ grub_halt (void)
 }
 
 void
-grub_exit (void)
+grub_exit (grub_exitcode_t exitcode __attribute__ ((unused)))
 {
   GRUB_ARC_FIRMWARE_VECTOR->exit ();
 
diff --git a/grub-core/kern/mips/loongson/init.c 
b/grub-core/kern/mips/loongson/init.c
index 7b96531..5958653 100644
--- a/grub-core/kern/mips/loongson/init.c
+++ b/grub-core/kern/mips/loongson/init.c
@@ -38,6 +38,7 @@
 #include <grub/serial.h>
 #include <grub/loader.h>
 #include <grub/at_keyboard.h>
+#include <grub/exitcode.h>
 
 grub_err_t
 grub_machine_mmap_iterate (grub_memory_hook_t hook, void *hook_data)
@@ -304,7 +305,7 @@ grub_halt (void)
 }
 
 void
-grub_exit (void)
+grub_exit (grub_exitcode_t exitcode __attribute__ ((unused)))
 {
   grub_halt ();
 }
diff --git a/grub-core/kern/mips/qemu_mips/init.c 
b/grub-core/kern/mips/qemu_mips/init.c
index be88b77..b807b78 100644
--- a/grub-core/kern/mips/qemu_mips/init.c
+++ b/grub-core/kern/mips/qemu_mips/init.c
@@ -17,6 +17,7 @@
 #include <grub/serial.h>
 #include <grub/loader.h>
 #include <grub/at_keyboard.h>
+#include <grub/exitcode.h>
 
 static inline int
 probe_mem (grub_addr_t addr)
@@ -75,7 +76,7 @@ grub_machine_fini (int flags __attribute__ ((unused)))
 }
 
 void
-grub_exit (void)
+grub_exit (grub_exitcode_t exitcode __attribute__ ((unused)))
 {
   grub_halt ();
 }
diff --git a/grub-core/kern/misc.c b/grub-core/kern/misc.c
index 906d2c2..0db98cc 100644
--- a/grub-core/kern/misc.c
+++ b/grub-core/kern/misc.c
@@ -24,6 +24,7 @@
 #include <grub/term.h>
 #include <grub/env.h>
 #include <grub/i18n.h>
+#include <grub/exitcode.h>
 
 union printf_arg
 {
@@ -1087,7 +1088,7 @@ grub_abort (void)
       grub_getkey ();
     }
 
-  grub_exit ();
+  grub_exit (GRUB_EXITCODE_NONE);
 }
 
 void
diff --git a/grub-core/kern/uboot/init.c b/grub-core/kern/uboot/init.c
index 5dcc106..1f27fa9 100644
--- a/grub-core/kern/uboot/init.c
+++ b/grub-core/kern/uboot/init.c
@@ -32,6 +32,7 @@
 #include <grub/uboot/api_public.h>
 #include <grub/cpu/system.h>
 #include <grub/cache.h>
+#include <grub/exitcode.h>
 
 extern char __bss_start[];
 extern char _end[];
@@ -43,7 +44,7 @@ extern grub_uint32_t grub_uboot_machine_type;
 extern grub_addr_t grub_uboot_boot_data;
 
 void
-grub_exit (void)
+grub_exit (grub_exitcode_t exitcode __attribute__ ((unused)))
 {
   grub_uboot_return (0);
 }
@@ -94,7 +95,7 @@ grub_machine_init (void)
   if (!ver)
     {
       /* Don't even have a console to log errors to... */
-      grub_exit ();
+      grub_exit (GRUB_EXITCODE_NONE);
     }
   else if (ver > API_SIG_VERSION)
     {
diff --git a/grub-core/kern/xen/init.c b/grub-core/kern/xen/init.c
index 0559c03..0fc3723 100644
--- a/grub-core/kern/xen/init.c
+++ b/grub-core/kern/xen/init.c
@@ -549,7 +549,7 @@ grub_machine_init (void)
 }
 
 void
-grub_exit (void)
+grub_exit (grub_exitcode_t exitcode __attribute__ ((unused)))
 {
   struct sched_shutdown arg;
 
diff --git a/include/grub/exitcode.h b/include/grub/exitcode.h
new file mode 100644
index 0000000..7f179f4
--- /dev/null
+++ b/include/grub/exitcode.h
@@ -0,0 +1,30 @@
+/* exitcode.h - declare exitcode types */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2015  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/>.
+ */
+
+#ifndef GRUB_EXITCODE_HEADER
+#define GRUB_EXITCODE_HEADER   1
+
+typedef enum
+  {
+    GRUB_EXITCODE_NONE = 0,
+    GRUB_EXITCODE_NEXT,
+  }
+grub_exitcode_t;
+
+#endif /* ! GRUB_EXITCODE_HEADER */
diff --git a/include/grub/misc.h b/include/grub/misc.h
index 2a9f87c..18dc77c 100644
--- a/include/grub/misc.h
+++ b/include/grub/misc.h
@@ -26,6 +26,7 @@
 #include <grub/err.h>
 #include <grub/i18n.h>
 #include <grub/compiler.h>
+#include <grub/exitcode.h>
 
 #define ALIGN_UP(addr, align) \
        ((addr + (typeof (addr)) align - 1) & ~((typeof (addr)) align - 1))
@@ -334,7 +335,7 @@ int EXPORT_FUNC(grub_vsnprintf) (char *str, grub_size_t n, 
const char *fmt,
 char *EXPORT_FUNC(grub_xasprintf) (const char *fmt, ...)
      __attribute__ ((format (GNU_PRINTF, 1, 2))) WARN_UNUSED_RESULT;
 char *EXPORT_FUNC(grub_xvasprintf) (const char *fmt, va_list args) 
WARN_UNUSED_RESULT;
-void EXPORT_FUNC(grub_exit) (void) __attribute__ ((noreturn));
+void EXPORT_FUNC(grub_exit) (grub_exitcode_t exitcode) __attribute__ 
((noreturn));
 grub_uint64_t EXPORT_FUNC(grub_divmod64) (grub_uint64_t n,
                                          grub_uint64_t d,
                                          grub_uint64_t *r);
-- 
2.5.0