From be9ee2df83a927d49184026154dd8d5039a8b664 Mon Sep 17 00:00:00 2001
From: Paulo Flabiano Smorigo <pfsmorigo@br.ibm.com>
Date: Thu, 20 Sep 2012 18:07:39 -0300
Subject: [PATCH] IBM client architecture (CAS) reboot support

This is an implementation of IBM client architecture (CAS) reboot for GRUB.

There are cases where the POWER firmware must reboot in order to support
specific features requested by a kernel. The kernel calls
ibm,client-architecture-support and it may either return or reboot with the new
feature set. eg:

Calling ibm,client-architecture-support.../
Elapsed time since release of system processors: 70959 mins 50 secs
Welcome to GRUB!

Instead of return to the GRUB menu, it will check if the flag for CAS reboot is
set. If so, grub will automatically boot the last booted kernel using the same
parameters
---
 grub-core/kern/ieee1275/openfw.c |   63 ++++++++++++++++++++++++++++++++++++++
 grub-core/normal/main.c          |   19 ++++++++++++
 grub-core/script/execute.c       |    7 +++++
 include/grub/ieee1275/ieee1275.h |    2 ++
 4 files changed, 91 insertions(+)

diff --git a/grub-core/kern/ieee1275/openfw.c b/grub-core/kern/ieee1275/openfw.c
index 40abaa3..c2b1bdf 100644
--- a/grub-core/kern/ieee1275/openfw.c
+++ b/grub-core/kern/ieee1275/openfw.c
@@ -523,3 +523,66 @@ grub_ieee1275_canonicalise_devname (const char *path)
   return NULL;
 }
 
+/* Check if it's a CAS reboot. If so, set the script to be executed.  */
+int
+grub_ieee1275_cas_reboot (char *script)
+{
+  grub_uint32_t ibm_ca_support_reboot;
+  grub_uint32_t ibm_fw_nbr_reboots;
+  char property_value[10];
+  grub_ssize_t actual;
+  grub_ieee1275_ihandle_t options;
+
+  if (grub_ieee1275_finddevice ("/options", &options) < 0)
+    return -1;
+
+  /* Check two properties, one is enough to get cas reboot value */
+  ibm_ca_support_reboot = 0;
+  if (grub_ieee1275_get_integer_property (grub_ieee1275_chosen,
+                                          "ibm,client-architecture-support-reboot",
+                                          &ibm_ca_support_reboot,
+                                          sizeof (ibm_ca_support_reboot),
+                                          &actual) >= 0)
+    grub_dprintf("ieee1275", "ibm,client-architecture-support-reboot: %u\n",
+                 ibm_ca_support_reboot);
+
+  ibm_fw_nbr_reboots = 0;
+  if (grub_ieee1275_get_property (options, "ibm,fw-nbr-reboots",
+                                  property_value, sizeof (property_value),
+                                  &actual) >= 0)
+    {
+      property_value[sizeof (property_value) - 1] = 0;
+      ibm_fw_nbr_reboots = (grub_uint8_t) grub_strtoul (property_value, 0, 10);
+      grub_dprintf("ieee1275", "ibm,fw-nbr-reboots: %u\n", ibm_fw_nbr_reboots);
+    }
+
+  if (ibm_ca_support_reboot || ibm_fw_nbr_reboots)
+    {
+      if (! grub_ieee1275_get_property_length (options, "boot-last-label", &actual))
+        {
+          if (actual > 1024)
+            script = grub_realloc (script, actual + 1);
+          grub_ieee1275_get_property (options, "boot-last-label", script, actual,
+                                      &actual);
+          return 0;
+        }
+    }
+
+  grub_ieee1275_set_boot_last_label ("");
+
+  return -1;
+}
+
+int grub_ieee1275_set_boot_last_label (const char *text)
+{
+  grub_ieee1275_ihandle_t options;
+  grub_ssize_t actual;
+
+  grub_dprintf("ieee1275", "set boot_last_label (size: %u)\n", grub_strlen(text));
+  if (! grub_ieee1275_finddevice ("/options", &options) &&
+      options != (grub_ieee1275_ihandle_t) -1)
+    grub_ieee1275_set_property (options, "boot-last-label", text,
+                                grub_strlen (text), &actual);
+  return 0;
+}
+
diff --git a/grub-core/normal/main.c b/grub-core/normal/main.c
index 39bb734..aa0b3e5 100644
--- a/grub-core/normal/main.c
+++ b/grub-core/normal/main.c
@@ -32,6 +32,9 @@
 #include <grub/i18n.h>
 #include <grub/charset.h>
 #include <grub/script_sh.h>
+#ifdef GRUB_MACHINE_IEEE1275
+#include <grub/ieee1275/ieee1275.h>
+#endif
 
 GRUB_MOD_LICENSE ("GPLv3+");
 
@@ -296,6 +299,22 @@ grub_normal_execute (const char *config, int nested, int batch)
     {
       menu = read_config_file (config);
 
+#ifdef GRUB_MACHINE_IEEE1275
+      int boot;
+      boot = 0;
+      char *script;
+      script = grub_malloc (1024);
+      if (! grub_ieee1275_cas_reboot (script))
+        {
+          char *dummy[1] = { NULL };
+          if (! grub_script_execute_sourcecode (script, 0, dummy))
+            boot = 1;
+        }
+      grub_free (script);
+      if (boot)
+        grub_command_execute ("boot", 0, 0);
+#endif
+
       /* Ignore any error.  */
       grub_errno = GRUB_ERR_NONE;
     }
diff --git a/grub-core/script/execute.c b/grub-core/script/execute.c
index b5e6eb0..4397540 100644
--- a/grub-core/script/execute.c
+++ b/grub-core/script/execute.c
@@ -27,6 +27,9 @@
 #include <grub/normal.h>
 #include <grub/extcmd.h>
 #include <grub/i18n.h>
+#ifdef GRUB_MACHINE_IEEE1275
+#include <grub/ieee1275/ieee1275.h>
+#endif
 
 /* Max digits for a char is 3 (0xFF is 255), similarly for an int it
    is sizeof (int) * 3, and one extra for a possible -ve sign.  */
@@ -820,6 +823,10 @@ grub_script_execute_sourcecode (const char *source, int argc, char **args)
   old_scope = scope;
   scope = &new_scope;
 
+#ifdef GRUB_MACHINE_IEEE1275
+  grub_ieee1275_set_boot_last_label (source);
+#endif
+
   while (source)
     {
       char *line;
diff --git a/include/grub/ieee1275/ieee1275.h b/include/grub/ieee1275/ieee1275.h
index 38a75fd..416a544 100644
--- a/include/grub/ieee1275/ieee1275.h
+++ b/include/grub/ieee1275/ieee1275.h
@@ -208,5 +208,7 @@ int EXPORT_FUNC(grub_ieee1275_devices_iterate) (int (*hook)
 char *EXPORT_FUNC(grub_ieee1275_get_aliasdevname) (const char *path);
 char *EXPORT_FUNC(grub_ieee1275_canonicalise_devname) (const char *path);
 char *EXPORT_FUNC(grub_ieee1275_get_device_type) (const char *path);
+int EXPORT_FUNC(grub_ieee1275_cas_reboot) (char *script);
+int EXPORT_FUNC(grub_ieee1275_set_boot_last_label) (const char *text);
 
 #endif /* ! GRUB_IEEE1275_HEADER */
-- 
1.7.10.4