[PATCH] IBM client architecture (CAS) reboot support

[Diego Domingos]

From: Paulo Flabiano Smorigo <pfsmorigo@br.ibm.com>

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 62929d983bf..2d53c0e8608 100644
--- a/grub-core/kern/ieee1275/openfw.c
+++ b/grub-core/kern/ieee1275/openfw.c
@@ -588,3 +588,66 @@ grub_ieee1275_get_boot_dev (void)
 
   return bootpath;
 }
+
+/* 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 78a70a8bf47..249e19bc788 100644
--- a/grub-core/normal/main.c
+++ b/grub-core/normal/main.c
@@ -33,6 +33,9 @@
 #include <grub/charset.h>
 #include <grub/script_sh.h>
 #include <grub/bufio.h>
+#ifdef GRUB_MACHINE_IEEE1275
+#include <grub/ieee1275/ieee1275.h>
+#endif
 
 GRUB_MOD_LICENSE ("GPLv3+");
 
@@ -275,6 +278,22 @@ 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))
+            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 a8502d90711..ab78ca87f90 100644
--- a/grub-core/script/execute.c
+++ b/grub-core/script/execute.c
@@ -27,6 +27,9 @@
 #include <grub/extcmd.h>
 #include <grub/i18n.h>
 #include <grub/verify.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.  */
@@ -877,6 +880,10 @@ grub_script_execute_sourcecode (const char *source)
   grub_err_t ret = 0;
   struct grub_script *parsed_script;
 
+#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 8868f3a756f..2310f33dbc2 100644
--- a/include/grub/ieee1275/ieee1275.h
+++ b/include/grub/ieee1275/ieee1275.h
@@ -252,6 +252,8 @@ int EXPORT_FUNC(grub_ieee1275_devalias_next) (struct 
grub_ieee1275_devalias *ali
 void EXPORT_FUNC(grub_ieee1275_children_peer) (struct grub_ieee1275_devalias 
*alias);
 void EXPORT_FUNC(grub_ieee1275_children_first) (const char *devpath,
                                                struct grub_ieee1275_devalias 
*alias);
+int EXPORT_FUNC(grub_ieee1275_cas_reboot) (char *script);
+int EXPORT_FUNC(grub_ieee1275_set_boot_last_label) (const char *text);
 
 char *EXPORT_FUNC(grub_ieee1275_get_boot_dev) (void);