[PATCH 1/2] efi: Add efitextmode command for getting/setting the text mode resolution

[Glenn Washburn]

This command is meant to behave similarly to the 'mode' command of the EFI
Shell application. One difference is that to set the mode the mode number
is given, not the rows and columns of the desired mode. Also supported are
the arguments "min" and "max", which set the mode to the minimum and
maximum mode respectively as calculated by the columns * rows of that mode.

Signed-off-by: Glenn Washburn <development@efficientek.com>
---
 grub-core/Makefile.core.def          |   6 ++
 grub-core/commands/efi/efitextmode.c | 118 +++++++++++++++++++++++++++
 2 files changed, 124 insertions(+)
 create mode 100644 grub-core/commands/efi/efitextmode.c

diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 726f51be7..b22e48f0f 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -813,6 +813,12 @@ module = {
   enable = efi;
 };
 
+module = {
+  name = efitextmode;
+  efi = commands/efi/efitextmode.c;
+  enable = efi;
+};
+
 module = {
   name = blocklist;
   common = commands/blocklist.c;
diff --git a/grub-core/commands/efi/efitextmode.c 
b/grub-core/commands/efi/efitextmode.c
new file mode 100644
index 000000000..fb72aa6f3
--- /dev/null
+++ b/grub-core/commands/efi/efitextmode.c
@@ -0,0 +1,118 @@
+/* efitextmode.c - command to get/set text mode resolution */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2003,2005,2006,2007,2009  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/mm.h>
+#include <grub/command.h>
+#include <grub/i18n.h>
+#include <grub/efi/efi.h>
+#include <grub/efi/api.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+static grub_err_t
+grub_cmd_efitextmode (grub_command_t cmd __attribute__ ((unused)),
+                     int argc, char **args)
+{
+  grub_efi_simple_text_output_interface_t *o;
+  unsigned long mode;
+  const char *p = NULL;
+  grub_efi_status_t status;
+  grub_efi_uintn_t columns, rows;
+  grub_efi_int32_t i;
+
+  if (argc > 1)
+    return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("at most one argument 
expected"));
+
+  o = grub_efi_system_table->con_out;
+
+  if (argc == 1)
+    {
+      if (grub_strcmp (args[0], "min") == 0)
+       mode = 0;
+      else if (grub_strcmp (args[0], "max") == 0)
+       mode = o->mode->max_mode - 1;
+      else
+       {
+         mode = grub_strtoul (args[0], &p, 0);
+
+         if (grub_errno != GRUB_ERR_NONE)
+           return grub_errno;
+
+         if (*args[0] == '\0' || *p != '\0')
+           return grub_error (GRUB_ERR_BAD_ARGUMENT,
+                              N_("non-numeric or invalid mode `%s'"),
+                              args[0]);
+       }
+
+      if (mode < (unsigned long) o->mode->max_mode)
+       {
+         if (mode != (unsigned long) o->mode->mode)
+           {
+             status = efi_call_2 (o->set_mode, o, (grub_efi_int32_t) mode);
+             if (status == GRUB_EFI_SUCCESS)
+               ;
+             else if (status == GRUB_EFI_DEVICE_ERROR)
+               return grub_error (GRUB_ERR_BAD_DEVICE,
+                                  N_("device error: could not set requested"
+                                     " mode"));
+             else if (status == GRUB_EFI_UNSUPPORTED)
+               return grub_error (GRUB_ERR_OUT_OF_RANGE,
+                                  N_("invalid mode: number not valid"));
+             else
+               return grub_error (GRUB_ERR_BAD_OS,
+                                  N_("unexpected EFI error number: `%u'"),
+                                  (unsigned) status);
+           }
+       }
+      else
+       return grub_error (GRUB_ERR_BAD_ARGUMENT,
+                          N_("invalid mode: `%lu' is greater than maximum"
+                             " mode `%lu'"),
+                          mode, (unsigned long) o->mode->max_mode);
+    }
+
+  if (argc == 0)
+    {
+      grub_printf_ (N_("Available modes for console output device.\n"));
+
+      for (i=0; i < o->mode->max_mode; i++)
+       if (GRUB_EFI_SUCCESS == efi_call_4 (o->query_mode, o, i,
+                                           &columns, &rows))
+         grub_printf_ (N_(" [%lu]  Col %5u Row %5u %c\n"),
+                       (unsigned long) i, (unsigned) columns, (unsigned) rows,
+                       (i == o->mode->mode) ? '*' : ' ');
+    }
+
+  return GRUB_ERR_NONE;
+}
+
+static grub_command_t cmd;
+
+GRUB_MOD_INIT(cmp)
+{
+  cmd = grub_register_command ("efitextmode", grub_cmd_efitextmode,
+                              N_("[min|max|mode_num]"), N_("Get or set EFI 
text mode."));
+}
+
+GRUB_MOD_FINI(cmp)
+{
+  grub_unregister_command (cmd);
+}
-- 
2.34.1