Handle Compatability issues for new BltoHbData location

Change-Id: I9ec35ca8dd513a5e31f69cd899fa5d1e00d41c63
RTC: 175114
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/42442
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Reviewed-by: Michael Baiocchi <mbaiocch@us.ibm.com>
Reviewed-by: Martin Gloff <mgloff@us.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>

src/bootloader/bootloader.C

@@ -164,8 +164,8 @@ namespace Bootloader{
             g_blData->blToHbData.sizeOfStructure = sizeof(BlToHbData);
         }
 
-        // Place structure into proper location for HB to find
-        memcpy(reinterpret_cast<void *>(BLTOHB_COMM_DATA_ADDR |
+        // Place BlToHb into proper location for HB to find
+        memcpy(reinterpret_cast<void *>(BLTOHB_COMM_DATA_ADDR_LATEST |
                                         IGNORE_HRMOR_MASK),
                &g_blData->blToHbData,
                sizeof(BlToHbData));

src/include/bootloader/bootloader.H

@@ -226,10 +226,10 @@ namespace Bootloader{
 #define HW_KEYS_HASH_ADDR (getHRMOR() + HBBL_EXCEPTION_VECTOR_SIZE \
                            + MAX_HBBL_SIZE - 64)
     /** Location of working copy of HBB with ECC */
-#define HBB_ECC_WORKING_ADDR    (getHRMOR() + ( 1*MEGABYTE))
+#define HBB_ECC_WORKING_ADDR    (getHRMOR() - ( 1*MEGABYTE))
 
     /** Location of working copy of HBB without ECC */
-#define HBB_WORKING_ADDR        (getHRMOR() - ( 1*MEGABYTE))
+#define HBB_WORKING_ADDR        (getHRMOR() + ( 1*MEGABYTE))
 
     /** Location of HBBL data */
 #define HBBL_DATA_ADDR          (getHRMOR() + HBBL_EXCEPTION_VECTOR_SIZE \
@@ -238,10 +238,6 @@ namespace Bootloader{
     /** Location of HBBL scratch space */
 #define HBBL_SCRATCH_SPACE_ADDR (getHRMOR() + (64*KILOBYTE))
 
-    /** Location of running copy of HBB */
-#define HBB_HRMOR               (getHRMOR() - ( 2*MEGABYTE))
-#define HBB_RUNNING_ADDR        (getHRMOR() - ( 2*MEGABYTE))
-
     /** Location of SBE HB communication area
         Defined in SBE code and bootloader.ld */
 #define SBE_HB_COMM_ADDR        (getHRMOR() + 0x4)

src/include/bootloader/bootloaderif.H

@@ -42,13 +42,21 @@ namespace Bootloader{
 
 #define MAX_HBB_SIZE (512 * KILOBYTE)
 
-// The Bootloader to Hostboot communication area exists after the working HBB
+// Location of running copy of HBB
 #ifdef BOOTLOADER
-#define BLTOHB_COMM_DATA_ADDR (getHRMOR() - ( 2*MEGABYTE) + MAX_HBB_SIZE)
+#define HBB_HRMOR               (getHRMOR() - ( 2*MEGABYTE))
+#define HBB_RUNNING_ADDR        (getHRMOR() - ( 2*MEGABYTE))
 #else
-#define BLTOHB_COMM_DATA_ADDR (getHRMOR() + MAX_HBB_SIZE)
+#define HBB_HRMOR               (getHRMOR())
+#define HBB_RUNNING_ADDR        (getHRMOR())
 #endif
 
+// Different Locations of BlToHBData struct over time.
+// New values make "_LATEST" and switch current "_LATEST" to "V<N>"
+// NOTE: Done this way to limit code space.
+#define BLTOHB_COMM_DATA_ADDR_V1 (HBB_HRMOR + 512*KILOBYTE)
+#define BLTOHB_COMM_DATA_ADDR_LATEST (HBB_HRMOR + MAX_HBB_SIZE)
+
 // Expected BlToHbData eye catch
 const uint64_t BLTOHB_EYECATCHER = 0x23626C746F686200; // #BLTOHB\0
 

src/kernel/kernel.C

@@ -61,6 +61,43 @@ class Kernel
 	Kernel() {};
 };
 
+
+/**
+ * @brief Searches multiple locations for the BlToHbData structure.
+ *
+ * @description Due to the possibility of a mismatch between the bootloader and
+ *              hostboot, we must check every location of this structure in
+ *              history. Searches latest to oldest.
+ *
+ * @return if found, pointer to structure
+ *         otherwise nullptr
+ */
+const Bootloader::BlToHbData* getBlToHbData()
+{
+    const Bootloader::BlToHbData* l_resultBltoHbData = nullptr;
+
+    // Order bootloader addr versions from most recent to oldest
+    // Note: Defined here to limit code space in bootloader code
+    static const std::array<uint64_t,2> BlToHbDataAddrs =
+    {
+        BLTOHB_COMM_DATA_ADDR_LATEST,
+        BLTOHB_COMM_DATA_ADDR_V1
+    };
+
+    for (auto addr : BlToHbDataAddrs)
+    {
+        const auto l_bltoHbData =
+                          reinterpret_cast<const Bootloader::BlToHbData*>(addr);
+        if(Bootloader::BlToHbDataValid(l_bltoHbData))
+        {
+            l_resultBltoHbData = l_bltoHbData;
+            break;
+        }
+    }
+
+    return l_resultBltoHbData;
+}
+
 extern "C"
 int main()
 {
@@ -75,13 +112,12 @@ int main()
     Kernel& kernel = Singleton<Kernel>::instance();
     kernel.cppBootstrap();
 
-    // Get pointer to BL and HB comm data
-    const auto l_pBltoHbData = reinterpret_cast<const Bootloader::BlToHbData*>(
-                                                        BLTOHB_COMM_DATA_ADDR);
 
-    if ( Bootloader::BlToHbDataValid(l_pBltoHbData) )
+    // Get pointer to BL and HB comm data
+    const auto l_pBltoHbData = getBlToHbData();
+    if ( l_pBltoHbData != nullptr )
     {
-        printk("BL to HB comm valid\n");
+        printk("Valid BlToHbData found at 0x%lX\n", reinterpret_cast<uint64_t>(l_pBltoHbData));
         // Initialize Secureboot Data class
         g_BlToHbDataManager.initValid(*l_pBltoHbData);
     }