From d8403d01f539d2776a4907f37b1436d884af8608 Mon Sep 17 00:00:00 2001
From: belliash <belliash@codingworkshop.eu.org>
Date: Wed, 22 Nov 2023 17:22:57 +0100
Subject: [PATCH] Verify kernel and boot loader compatibility

---
 sdk/xtdk/xtfw.h              |  8 ++++--
 xtldr/modules/xtos/xtos.c    |  5 ++--
 xtoskrnl/ke/amd64/krnlinit.c |  3 ---
 xtoskrnl/ke/i686/krnlinit.c  |  3 ---
 xtoskrnl/ke/krnlinit.c       | 47 +++++++++++++++++++++---------------
 5 files changed, 36 insertions(+), 30 deletions(-)

diff --git a/sdk/xtdk/xtfw.h b/sdk/xtdk/xtfw.h
index e06de36..e7b4578 100644
--- a/sdk/xtdk/xtfw.h
+++ b/sdk/xtdk/xtfw.h
@@ -16,6 +16,9 @@
 /* Version number of the current kernel initialization block */
 #define INITIALIZATION_BLOCK_VERSION                            1
 
+/* Version number of the current XTOS loader protocol */
+#define BOOT_PROTOCOL_VERSION                                   1
+
 /* Memory allocation structures */
 typedef enum _LOADER_MEMORY_TYPE
 {
@@ -115,11 +118,12 @@ typedef struct _LOADER_MEMORY_MAPPING
 /* Loader provided information needed by the kernel to initialize */
 typedef struct _KERNEL_INITIALIZATION_BLOCK
 {
+    ULONG BlockSize;
+    ULONG BlockVersion;
+    ULONG ProtocolVersion;
     LIST_ENTRY LoadOrderListHead;
     LIST_ENTRY MemoryDescriptorListHead;
     LIST_ENTRY BootDriverListHead;
-    ULONG Size;
-    ULONG Version;
     LOADER_INFORMATION_BLOCK LoaderInformation;
     FIRMWARE_INFORMATION_BLOCK FirmwareInformation;
 } KERNEL_INITIALIZATION_BLOCK, *PKERNEL_INITIALIZATION_BLOCK;
diff --git a/xtldr/modules/xtos/xtos.c b/xtldr/modules/xtos/xtos.c
index c45b169..07b963f 100644
--- a/xtldr/modules/xtos/xtos.c
+++ b/xtldr/modules/xtos/xtos.c
@@ -352,8 +352,9 @@ XtpInitializeLoaderBlock(IN PLIST_ENTRY MemoryMappings,
     RtlZeroMemory(LoaderBlock, sizeof(KERNEL_INITIALIZATION_BLOCK));
 
     /* Set basic loader block properties */
-    LoaderBlock->Size = sizeof(KERNEL_INITIALIZATION_BLOCK);
-    LoaderBlock->Version = INITIALIZATION_BLOCK_VERSION;
+    LoaderBlock->BlockSize = sizeof(KERNEL_INITIALIZATION_BLOCK);
+    LoaderBlock->BlockVersion = INITIALIZATION_BLOCK_VERSION;
+    LoaderBlock->ProtocolVersion = BOOT_PROTOCOL_VERSION;
 
     /* Set LoaderInformation block properties */
     LoaderBlock->LoaderInformation.DbgPrint = XtLdrProtocol->DbgPrint;
diff --git a/xtoskrnl/ke/amd64/krnlinit.c b/xtoskrnl/ke/amd64/krnlinit.c
index 1232255..429fe26 100644
--- a/xtoskrnl/ke/amd64/krnlinit.c
+++ b/xtoskrnl/ke/amd64/krnlinit.c
@@ -82,9 +82,6 @@ XTAPI
 VOID
 KepStartKernel(VOID)
 {
-    /* Print debug message */
-    DebugPrint(L"Starting ExectOS ...\n");
-
     /* Initialize XTOS kernel */
     KepInitializeKernel();
 
diff --git a/xtoskrnl/ke/i686/krnlinit.c b/xtoskrnl/ke/i686/krnlinit.c
index 0356add..604079c 100644
--- a/xtoskrnl/ke/i686/krnlinit.c
+++ b/xtoskrnl/ke/i686/krnlinit.c
@@ -82,9 +82,6 @@ XTAPI
 VOID
 KepStartKernel(VOID)
 {
-    /* Print debug message */
-    DebugPrint(L"Starting ExectOS ...\n");
-
     /* Initialize XTOS kernel */
     KepInitializeKernel();
 
diff --git a/xtoskrnl/ke/krnlinit.c b/xtoskrnl/ke/krnlinit.c
index 958f465..bb29c22 100644
--- a/xtoskrnl/ke/krnlinit.c
+++ b/xtoskrnl/ke/krnlinit.c
@@ -23,29 +23,36 @@ XTAPI
 VOID
 KeStartXtSystem(IN PKERNEL_INITIALIZATION_BLOCK Parameters)
 {
-    /* Check if debugging enabled and if boot loader provided routine for debug printing */
-    if(DEBUG && Parameters->LoaderInformation.DbgPrint)
-    {
-        /* Use loader's provided DbgPrint() routine for early printing to serial console */
-        KeDbgPrint = Parameters->LoaderInformation.DbgPrint;
-    }
-
-
-    /* Print some message to serial console and test kernel parameters */
-    DebugPrint(L"Hello world from ExectOS kernel!\n");
-    DebugPrint(L"\n\n------ Kernel parameters block ------\n"
-             L"Loader block size: %lu\n"
-             L"Loader block version: %lu\n"
-             L"EFI Revision: %lu\n",
-             Parameters->Size,
-             Parameters->Version,
-             Parameters->FirmwareInformation.EfiFirmware.EfiVersion
-            );
-
-
     /* Save the kernel initialization block */
     KeInitializationBlock = Parameters;
 
+    /* Verify kernel and boot loader compatibility */
+    if(KeInitializationBlock->BlockSize != sizeof(KERNEL_INITIALIZATION_BLOCK) ||
+       KeInitializationBlock->BlockVersion != INITIALIZATION_BLOCK_VERSION ||
+       KeInitializationBlock->ProtocolVersion != BOOT_PROTOCOL_VERSION)
+    {
+        /* Kernel and boot loader version mismatch */
+        for(;;)
+        {
+            /* Halt system */
+            ArClearInterruptFlag();
+            ArHalt();
+        }
+    }
+
+    /* Check if debugging enabled and if boot loader provided routine for debug printing */
+    if(DEBUG && KeInitializationBlock->LoaderInformation.DbgPrint)
+    {
+        /* Use loader's provided DbgPrint() routine for early printing to serial console */
+        KeDbgPrint = KeInitializationBlock->LoaderInformation.DbgPrint;
+    }
+
+    /* Announce kernel startup */
+    DebugPrint(L"Starting ExectOS v%d.%d (%s-%s-%s-%s / %s %s)\n",
+               XTOS_VERSION_MAJOR, XTOS_VERSION_MINOR, XTOS_VERSION_DATE,
+               XTOS_VERSION_BUILD, XTOS_VERSION_ARCH, XTOS_VERSION_HASH,
+               XTOS_COMPILER_NAME, XTOS_COMPILER_VERSION);
+
     /* Initialize boot CPU */
     ArInitializeProcessor();