From 8e61e95cc2d3409937a1226a39900eb5cf24597f Mon Sep 17 00:00:00 2001
From: Rafal Kupiec <belliash@codingworkshop.eu.org>
Date: Sun, 28 Jan 2024 23:16:01 +0100
Subject: [PATCH] Implement BlPhysicalAddressToVirtual() routine

---
 sdk/xtdk/bltypes.h     |  2 ++
 xtldr/includes/xtldr.h |  6 ++++++
 xtldr/memory.c         | 26 ++++++++++++++++++++++++++
 xtldr/protocol.c       |  1 +
 4 files changed, 35 insertions(+)

diff --git a/sdk/xtdk/bltypes.h b/sdk/xtdk/bltypes.h
index 7611706..d39b39d 100644
--- a/sdk/xtdk/bltypes.h
+++ b/sdk/xtdk/bltypes.h
@@ -91,6 +91,7 @@ typedef EFI_STATUS (*PBL_MAP_VIRTUAL_MEMORY)(IN OUT PXTBL_PAGE_MAPPING PageMap,
 typedef EFI_STATUS (*PBL_OPEN_VOLUME)(IN PEFI_DEVICE_PATH_PROTOCOL DevicePath, OUT PEFI_HANDLE DiskHandle, OUT PEFI_FILE_HANDLE *FsHandle);
 typedef EFI_STATUS (*PBL_OPEN_PROTOCOL)(OUT PEFI_HANDLE Handle, OUT PVOID *ProtocolHandler, IN PEFI_GUID ProtocolGuid);
 typedef EFI_STATUS (*PBL_OPEN_PROTOCOL_HANDLE)(IN EFI_HANDLE Handle, OUT PVOID *ProtocolHandler, IN PEFI_GUID ProtocolGuid);
+typedef PVOID (*PBL_PHYSICAL_ADDRESS_TO_VIRTUAL)(IN PVOID PhysicalAddress, IN PVOID PhysicalBase, IN PVOID VirtualBase);
 typedef EFI_STATUS (*PBL_POWER_SYSTEM)();
 typedef EFI_STATUS (*PBL_READ_FILE)(IN PEFI_FILE_HANDLE DirHandle, IN CONST PWCHAR FileName, OUT PVOID *FileData, OUT PSIZE_T FileSize);
 typedef EFI_STATUS (*PBL_REGISTER_BOOT_PROTOCOL)(IN PWCHAR SystemType, IN PEFI_GUID BootProtocolGuid);
@@ -315,6 +316,7 @@ typedef struct _XTBL_LOADER_PROTOCOL
         PBL_MAP_EFI_MEMORY MapEfiMemory;
         PBL_MAP_PAGE MapPage;
         PBL_MAP_VIRTUAL_MEMORY MapVirtualMemory;
+        PBL_PHYSICAL_ADDRESS_TO_VIRTUAL PhysicalAddressToVirtual;
         PBL_SET_MEMORY SetMemory;
         PBL_ZERO_MEMORY ZeroMemory;
     } Memory;
diff --git a/xtldr/includes/xtldr.h b/xtldr/includes/xtldr.h
index 93c4b98..032e4cb 100644
--- a/xtldr/includes/xtldr.h
+++ b/xtldr/includes/xtldr.h
@@ -247,6 +247,12 @@ BlOpenProtocolHandle(IN EFI_HANDLE Handle,
                      OUT PVOID *ProtocolHandler,
                      IN PEFI_GUID ProtocolGuid);
 
+XTCDECL
+PVOID
+BlPhysicalAddressToVirtual(IN PVOID PhysicalAddress,
+                           IN PVOID PhysicalBase,
+                           IN PVOID VirtualBase);
+
 XTCDECL
 VOID
 BlQueryConsoleMode(OUT PUINT_PTR ResX,
diff --git a/xtldr/memory.c b/xtldr/memory.c
index ccf0a5c..965dd73 100644
--- a/xtldr/memory.c
+++ b/xtldr/memory.c
@@ -488,6 +488,32 @@ BlMapVirtualMemory(IN OUT PXTBL_PAGE_MAPPING PageMap,
     return STATUS_EFI_SUCCESS;
 }
 
+/**
+ * Converts physical address to virtual address based on physical base and virtual base.
+ *
+ * @param PhysicalAddress
+ *        Specifies physical address that will be converted to virtual address.
+ *
+ * @param PhysicalBase
+ *        Supplies a physical base address.
+ *
+ * @param VirtualBase
+ *        Supplies a virtual base address.
+ *
+ * @return This routine returns a mapped virtual address.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+PVOID
+BlPhysicalAddressToVirtual(IN PVOID PhysicalAddress,
+                           IN PVOID PhysicalBase,
+                           IN PVOID VirtualBase)
+{
+    /* Convert physical address to virtual address */
+    return (PUCHAR)VirtualBase + ((PUCHAR)PhysicalAddress - (PUCHAR)PhysicalBase);
+}
+
 /**
  * Converts EFI memory type to XTLDR memory type.
  *
diff --git a/xtldr/protocol.c b/xtldr/protocol.c
index 425675d..5f8fe15 100644
--- a/xtldr/protocol.c
+++ b/xtldr/protocol.c
@@ -636,6 +636,7 @@ BlpInstallXtLoaderProtocol()
     BlpLdrProtocol.Memory.MapEfiMemory = BlMapEfiMemory;
     BlpLdrProtocol.Memory.MapPage = BlMapPage;
     BlpLdrProtocol.Memory.MapVirtualMemory = BlMapVirtualMemory;
+    BlpLdrProtocol.Memory.PhysicalAddressToVirtual = BlPhysicalAddressToVirtual;
     BlpLdrProtocol.Memory.SetMemory = RtlSetMemory;
     BlpLdrProtocol.Memory.ZeroMemory = RtlZeroMemory;
     BlpLdrProtocol.Protocol.Close = BlCloseProtocol;