1 files changed, 126 insertions, 0 deletions
diff --git a/grub-core/commands/i386/pc/halt.c b/grub-core/commands/i386/pc/halt.c
new file mode 100644
index 0000000..1e7c2c9
--- /dev/null
+++ b/grub-core/commands/i386/pc/halt.c
@@ -0,0 +1,126 @@
+/* halt.c - command to halt the computer.  */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2005,2007,2009  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/dl.h>
+#include <grub/misc.h>
+#include <grub/extcmd.h>
+#include <grub/i18n.h>
+#include <grub/machine/int.h>
+#include <grub/acpi.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+static const struct grub_arg_option options[] =
+  {
+    {"no-apm", 'n', 0, N_("Do not use APM to halt the computer."), 0, 0},
+    {0, 0, 0, 0, 0, 0}
+  };
+
+static inline void __attribute__ ((noreturn))
+stop (void)
+{
+  while (1)
+    {
+      asm volatile ("hlt");
+    }
+}
+/*
+ * Halt the system, using APM if possible. If NO_APM is true, don't use
+ * APM even if it is available.
+ */
+void  __attribute__ ((noreturn))
+grub_halt (int no_apm)
+{
+  struct grub_bios_int_registers regs;
+
+  grub_acpi_halt ();
+
+  if (no_apm)
+    stop ();
+
+  /* detect APM */
+  regs.eax = 0x5300;
+  regs.ebx = 0;
+  regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
+  grub_bios_interrupt (0x15, &regs);
+  
+  if (regs.flags & GRUB_CPU_INT_FLAGS_CARRY)
+    stop ();
+
+  /* disconnect APM first */
+  regs.eax = 0x5304;
+  regs.ebx = 0;
+  regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
+  grub_bios_interrupt (0x15, &regs);
+
+  /* connect APM */
+  regs.eax = 0x5301;
+  regs.ebx = 0;
+  regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
+  grub_bios_interrupt (0x15, &regs);
+  if (regs.flags & GRUB_CPU_INT_FLAGS_CARRY)
+    stop ();
+
+  /* set APM protocol level - 1.1 or bust. (this covers APM 1.2 also) */
+  regs.eax = 0x530E;
+  regs.ebx = 0;
+  regs.ecx = 0x0101;
+  regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
+  grub_bios_interrupt (0x15, &regs);
+  if (regs.flags & GRUB_CPU_INT_FLAGS_CARRY)
+    stop ();
+
+  /* set the power state to off */
+  regs.eax = 0x5307;
+  regs.ebx = 1;
+  regs.ecx = 3;
+  regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
+  grub_bios_interrupt (0x15, &regs);
+
+  /* shouldn't reach here */
+  stop ();
+}
+
+static grub_err_t __attribute__ ((noreturn))
+grub_cmd_halt (grub_extcmd_context_t ctxt,
+	       int argc __attribute__ ((unused)),
+	       char **args __attribute__ ((unused)))
+
+{
+  struct grub_arg_list *state = ctxt->state;
+  int no_apm = 0;
+
+  if (state[0].set)
+    no_apm = 1;
+  grub_halt (no_apm);
+}
+
+static grub_extcmd_t cmd;
+
+GRUB_MOD_INIT(halt)
+{
+  cmd = grub_register_extcmd ("halt", grub_cmd_halt, 0, "[-n]",
+			      N_("Halt the system, if possible using APM."),
+			      options);
+}
+
+GRUB_MOD_FINI(halt)
+{
+  grub_unregister_extcmd (cmd);
+}