From a4b9f495e5e3b55a4356c0c8bb95d661fb94266c Mon Sep 17 00:00:00 2001
From: Aiken Harris <harraiken91@gmail.com>
Date: Tue, 27 Jan 2026 16:50:11 +0100
Subject: [PATCH] Calculate total boot image size and pass it to kernel

---
 boot/xtldr/modules/xtos_o/xtos.cc | 6 ++++++
 sdk/xtdk/xtfw.h                   | 1 +
 2 files changed, 7 insertions(+)

diff --git a/boot/xtldr/modules/xtos_o/xtos.cc b/boot/xtldr/modules/xtos_o/xtos.cc
index 7334693..aabecb9 100644
--- a/boot/xtldr/modules/xtos_o/xtos.cc
+++ b/boot/xtldr/modules/xtos_o/xtos.cc
@@ -234,6 +234,9 @@ Xtos::GetMemoryDescriptorList(IN PXTBL_PAGE_MAPPING PageMap,
 
     XtLdrProtocol->Memory.PhysicalListToVirtual(PageMap, MemoryDescriptorList, PhysicalBase, *VirtualAddress);
 
+    /* Calculate next valid virtual address */
+    *VirtualAddress = (PUINT8)*VirtualAddress + (Pages * EFI_PAGE_SIZE);
+
     return STATUS_EFI_SUCCESS;
 }
 
@@ -469,6 +472,9 @@ Xtos::InitializeLoaderBlock(IN PXTBL_PAGE_MAPPING PageMap,
     XtLdrProtocol->LinkedList.InitializeHead(&LoaderBlock->MemoryDescriptorListHead);
     GetMemoryDescriptorList(PageMap, VirtualAddress, &LoaderBlock->MemoryDescriptorListHead);
 
+    /* Set boot image size */
+    LoaderBlock->BootImageSize = (PFN_NUMBER)(((ULONGLONG)*VirtualAddress - KSEG0_BASE) / EFI_PAGE_SIZE);
+
     /* Return success */
     return STATUS_EFI_SUCCESS;
 }
diff --git a/sdk/xtdk/xtfw.h b/sdk/xtdk/xtfw.h
index 1a4642a..fbe3965 100644
--- a/sdk/xtdk/xtfw.h
+++ b/sdk/xtdk/xtfw.h
@@ -107,6 +107,7 @@ typedef struct _KERNEL_INITIALIZATION_BLOCK
     ULONG BlockVersion;
     ULONG ProtocolVersion;
     PWCHAR KernelParameters;
+    PFN_NUMBER BootImageSize;
     LIST_ENTRY LoadOrderListHead;
     LIST_ENTRY MemoryDescriptorListHead;
     LIST_ENTRY BootDriverListHead;