[reactos] 01/01: [FREELDR] Enable UEFI boot for x86 and amd64 (#5267)

[Justin Miller]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=ff3dadf89d999c0212de9…

commit ff3dadf89d999c0212de9ec4fa9d7f7c05ee2967
Author:     Justin Miller <justin.miller(a)reactos.org>
AuthorDate: Wed Oct 11 12:45:08 2023 -0700
Commit:     GitHub <noreply(a)github.com>
CommitDate: Wed Oct 11 12:45:08 2023 -0700

    [FREELDR] Enable UEFI boot for x86 and amd64 (#5267)
    
    Co-authored-by: Stanislav Motylkov <x86corez(a)gmail.com>
    Co-authored-by: Hermès BÉLUSCA - MAÏTO <hermes.belusca-maito(a)reactos.org>
    
    - Allow to boot NT kernel on UEFI systems with our 2 primary supported architectures
    - Implement remaining code needed to pass execution to x86 and amd64 kernels
    
    CORE-11954
---
 boot/freeldr/freeldr/arch/uefi/amd64/uefiasm.S |  85 ++++++++++++++
 boot/freeldr/freeldr/arch/uefi/i386/uefiasm.S  | 109 ++++++++++++++++++
 boot/freeldr/freeldr/arch/uefi/stubs.c         |   6 -
 boot/freeldr/freeldr/arch/uefi/ueficon.c       |   1 -
 boot/freeldr/freeldr/arch/uefi/uefihw.c        | 149 +++++++++++++++++++++++++
 boot/freeldr/freeldr/arch/uefi/uefildr.c       |  55 ++++++++-
 boot/freeldr/freeldr/arch/uefi/uefimem.c       |  81 +++++---------
 boot/freeldr/freeldr/arch/uefi/uefisetup.c     |   1 -
 boot/freeldr/freeldr/uefi.cmake                |  13 ++-
 9 files changed, 435 insertions(+), 65 deletions(-)

diff --git a/boot/freeldr/freeldr/arch/uefi/amd64/uefiasm.S
b/boot/freeldr/freeldr/arch/uefi/amd64/uefiasm.S
new file mode 100644
index 00000000000..c4cd78d1e0b
--- /dev/null
+++ b/boot/freeldr/freeldr/arch/uefi/amd64/uefiasm.S
@@ -0,0 +1,85 @@
+/*
+ * PROJECT:     FreeLoader UEFI Support
+ * LICENSE:     GPL-2.0-or-later (https://spdx.org/licenses/GPL-2.0-or-later)
+ * PURPOSE:     x64 assembly UEFI escape helper functions
+ * COPYRIGHT:   Copyright 2023 Justin Miller <justinmiller100(a)gmail.com>
+ */
+
+#include <asm.inc>
+#include <arch/pc/x86common.h>
+#include <arch/pc/pcbios.h>
+
+EXTERN UefiServiceStack:QWORD
+EXTERN BasicStack:QWORD
+EXTERN ExecuteLoaderCleanly:PROC
+EXTERN UefiExitBootServices:PROC
+
+.code64
+
+// void _exituefi(VOID)
+PUBLIC _exituefi
+_exituefi:
+    /* Save non-volatile registers */
+    push rbp
+    push rsi
+    push rdi
+    push rbx
+
+    /* Save the old stack */
+    mov rbx, rsp
+
+    /* Load the new stack */
+    xor rbp, rbp
+    mov rsp, qword ptr UefiServiceStack[rip]
+
+    /* Call the entry routine, passing the parameters */
+    mov rax, UefiExitBootServices[rip]
+    call rax
+
+    /* Retore old stack */
+    mov rsp, rbx
+
+    /* Retore non-volatiles */
+    pop rbx
+    pop rdi
+    pop rsi
+    pop rbp
+
+#ifdef _USE_ML
+    lgdt fword ptr [_gdtptr]
+#else
+    lgdt cs:[_gdtptr][rip] /* GAS isn't my friend - avoid letting it generate
absolute addressing */
+#endif
+
+    /* All done */
+    ret
+
+// void _changestack(VOID)
+PUBLIC _changestack
+_changestack:
+    mov rax, rsp
+    mov rsp, BasicStack[rip]
+    push rax
+    call ExecuteLoaderCleanly[rip]
+    ret
+
+.align 8
+gdt:
+    .word HEX(0000), HEX(0000), HEX(0000), HEX(0000) /* 00: NULL descriptor */
+    .word HEX(0000), HEX(0000), HEX(0000), HEX(0000) /* 08: */
+    .word HEX(0000), HEX(0000), HEX(9800), HEX(0020) /* 10: long mode CS */
+    .word HEX(FFFF), HEX(0000), HEX(F300), HEX(00CF) /* 18: long mode DS */
+    .word HEX(FFFF), HEX(0000), HEX(9E00), HEX(0000) /* 20: 16-bit real mode CS */
+    .word HEX(FFFF), HEX(0000), HEX(9200), HEX(0000) /* 28: 16-bit real mode DS */
+    .word HEX(FFFF), HEX(0000), HEX(9B00), HEX(00CF) /* 30: compat mode CS */
+
+/* GDT table pointer */
+_gdtptr:
+    .word HEX(37) /* Limit */
+#ifdef _USE_ML
+    .quad gdt     /* Base Address */
+#else
+    .quad gdt, 0  /* Base Address */
+#endif
+
+END
diff --git a/boot/freeldr/freeldr/arch/uefi/i386/uefiasm.S
b/boot/freeldr/freeldr/arch/uefi/i386/uefiasm.S
new file mode 100644
index 00000000000..64de25daa20
--- /dev/null
+++ b/boot/freeldr/freeldr/arch/uefi/i386/uefiasm.S
@@ -0,0 +1,109 @@
+/*
+ * PROJECT:     FreeLoader UEFI Support
+ * LICENSE:     GPL-2.0-or-later (https://spdx.org/licenses/GPL-2.0-or-later)
+ * PURPOSE:     i386 assembly UEFI escape helper functions
+ * COPYRIGHT:   Copyright 2023 Justin Miller &lt;justinmiller100(a)gmail.com&gt;
+ */
+
+#include <asm.inc>
+#include <arch/pc/x86common.h>
+#include <arch/pc/pcbios.h>
+
+PUBLIC _gdtptr
+PUBLIC _i386idtptr
+PUBLIC __changestack
+EXTERN _UefiServiceStack:DWORD
+EXTERN _i386Idt:DWORD
+EXTERN _ExecuteLoaderCleanly:PROC
+EXTERN _UefiExitBootServices:PROC
+EXTERN _BasicStack:DWORD
+.code32
+
+// void __exituefi(VOID)
+PUBLIC __exituefi
+__exituefi:
+    push ebp
+    push esi
+    push edi
+    push ebx
+
+    /* Save the old stack */
+    mov ebx, esp
+
+    /* Load the new stack */
+    xor ebp, ebp
+    mov esp, _UefiServiceStack
+
+    /* Call the entry routine, passing the parameters */
+    call _UefiExitBootServices
+
+    /* Retore old stack */
+    mov esp, ebx
+
+    /* Retore non-volatiles */
+    pop ebx
+    pop edi
+    pop esi
+    pop ebp
+
+#ifdef _USE_ML
+    lidt fword ptr ds:[_i386idtptr]
+    lgdt fword ptr [_gdtptr]
+#else
+    lgdt cs:[_gdtptr]
+    lidt _i386idtptr
+#endif
+
+    /* All done */
+    ret
+
+// void __reloadsegment(VOID)
+PUBLIC __changestack
+__changestack:
+    mov eax, esp
+    mov esp, _BasicStack
+    push eax
+    call _ExecuteLoaderCleanly
+    ret
+
+    .align 4    /* force 4-byte alignment */
+gdt:
+    /* NULL Descriptor */
+   .word HEX(0000)
+   .word HEX(0000)
+   .word HEX(0000)
+   .word HEX(0000)
+
+    /* 32-bit flat CS */
+    .word HEX(FFFF)
+    .word HEX(0000)
+    .word HEX(9A00)
+    .word HEX(00CF)
+
+    /* 32-bit flat DS */
+    .word HEX(FFFF)
+    .word HEX(0000)
+    .word HEX(9200)
+    .word HEX(00CF)
+
+    /* 16-bit real mode CS */
+    .word HEX(FFFF)
+    .word HEX(0000)
+    .word HEX(9E00)
+    .word HEX(0000)
+
+    /* 16-bit real mode DS */
+    .word HEX(FFFF)
+    .word HEX(0000)
+    .word HEX(9200)
+    .word HEX(0000)
+
+/* GDT table pointer */
+_gdtptr:
+    .word HEX(27)  /* Limit */
+    .long gdt, 0   /* Base Address */
+
+_i386idtptr:
+    .word 255      /* Limit */
+    .long _i386Idt /* Base Address */
+END
diff --git a/boot/freeldr/freeldr/arch/uefi/stubs.c
b/boot/freeldr/freeldr/arch/uefi/stubs.c
index ac5cebab51c..e9263d60ba3 100644
--- a/boot/freeldr/freeldr/arch/uefi/stubs.c
+++ b/boot/freeldr/freeldr/arch/uefi/stubs.c
@@ -43,12 +43,6 @@ UefiGetExtendedBIOSData(PULONG ExtendedBIOSDataArea,
 
 }
 
-PCONFIGURATION_COMPONENT_DATA
-UefiHwDetect(VOID)
-{
-    return 0;
-}
-
 VOID
 UefiPcBeep(VOID)
 {
diff --git a/boot/freeldr/freeldr/arch/uefi/ueficon.c
b/boot/freeldr/freeldr/arch/uefi/ueficon.c
index 000b6b9d3a7..6dc6eb5b8b6 100644
--- a/boot/freeldr/freeldr/arch/uefi/ueficon.c
+++ b/boot/freeldr/freeldr/arch/uefi/ueficon.c
@@ -138,6 +138,5 @@ UefiConsGetCh(VOID)
     /* UEFI will stack input requests, we have to clear it */
     Key.UnicodeChar = 0;
     Key.ScanCode = 0;
-    GlobalSystemTable->ConIn->Reset(GlobalSystemTable->ConIn, FALSE);
     return KeyOutput;
 }
diff --git a/boot/freeldr/freeldr/arch/uefi/uefihw.c
b/boot/freeldr/freeldr/arch/uefi/uefihw.c
new file mode 100644
index 00000000000..8dcf9602274
--- /dev/null
+++ b/boot/freeldr/freeldr/arch/uefi/uefihw.c
@@ -0,0 +1,149 @@
+/*
+ * PROJECT:     FreeLoader UEFI Support
+ * LICENSE:     GPL-2.0-or-later (https://spdx.org/licenses/GPL-2.0-or-later)
+ * PURPOSE:     Hardware detection routines
+ * COPYRIGHT:   Copyright 2022 Justin Miller &lt;justinmiller100(a)gmail.com&gt;
+ */
+
+/* INCLUDES ******************************************************************/
+
+#include <uefildr.h>
+
+#include <debug.h>
+DBG_DEFAULT_CHANNEL(WARNING);
+
+/* GLOBALS *******************************************************************/
+
+extern EFI_SYSTEM_TABLE * GlobalSystemTable;
+extern EFI_HANDLE GlobalImageHandle;
+extern UCHAR PcBiosDiskCount;
+extern EFI_MEMORY_DESCRIPTOR* EfiMemoryMap;
+extern UINT32 FreeldrDescCount;
+
+BOOLEAN AcpiPresent = FALSE;
+
+/* FUNCTIONS *****************************************************************/
+
+static
+PRSDP_DESCRIPTOR
+FindAcpiBios(VOID)
+{
+    UINTN i;
+    RSDP_DESCRIPTOR* rsdp = NULL;
+    EFI_GUID acpi2_guid = EFI_ACPI_20_TABLE_GUID;
+
+    for (i = 0; i < GlobalSystemTable->NumberOfTableEntries; i++)
+    {
+        if (!memcmp(&GlobalSystemTable->ConfigurationTable[i].VendorGuid,
+                    &acpi2_guid, sizeof(acpi2_guid)))
+        {
+            rsdp =
(RSDP_DESCRIPTOR*)GlobalSystemTable->ConfigurationTable[i].VendorTable;
+            break;
+        }
+    }
+
+    return rsdp;
+}
+
+VOID
+DetectAcpiBios(PCONFIGURATION_COMPONENT_DATA SystemKey, ULONG *BusNumber)
+{
+    PCONFIGURATION_COMPONENT_DATA BiosKey;
+    PCM_PARTIAL_RESOURCE_LIST PartialResourceList;
+    PCM_PARTIAL_RESOURCE_DESCRIPTOR PartialDescriptor;
+    PRSDP_DESCRIPTOR Rsdp;
+    PACPI_BIOS_DATA AcpiBiosData;
+    ULONG TableSize;
+
+    Rsdp = FindAcpiBios();
+
+    if (Rsdp)
+    {
+        /* Set up the flag in the loader block */
+        AcpiPresent = TRUE;
+
+        /* Calculate the table size */
+        TableSize = FreeldrDescCount * sizeof(BIOS_MEMORY_MAP) +
+            sizeof(ACPI_BIOS_DATA) - sizeof(BIOS_MEMORY_MAP);
+
+        /* Set 'Configuration Data' value */
+        PartialResourceList = FrLdrHeapAlloc(sizeof(CM_PARTIAL_RESOURCE_LIST) +
+                                             TableSize, TAG_HW_RESOURCE_LIST);
+        if (PartialResourceList == NULL)
+        {
+            ERR("Failed to allocate resource descriptor\n");
+            return;
+        }
+
+        RtlZeroMemory(PartialResourceList, sizeof(CM_PARTIAL_RESOURCE_LIST) +
TableSize);
+        PartialResourceList->Version = 0;
+        PartialResourceList->Revision = 0;
+        PartialResourceList->Count = 1;
+
+        PartialDescriptor = &PartialResourceList->PartialDescriptors[0];
+        PartialDescriptor->Type = CmResourceTypeDeviceSpecific;
+        PartialDescriptor->ShareDisposition = CmResourceShareUndetermined;
+        PartialDescriptor->u.DeviceSpecificData.DataSize = TableSize;
+
+        /* Fill the table */
+        AcpiBiosData =
(PACPI_BIOS_DATA)&PartialResourceList->PartialDescriptors[1];
+
+        if (Rsdp->revision > 0)
+        {
+            TRACE("ACPI >1.0, using XSDT address\n");
+            AcpiBiosData->RSDTAddress.QuadPart = Rsdp->xsdt_physical_address;
+        }
+        else
+        {
+            TRACE("ACPI 1.0, using RSDT address\n");
+            AcpiBiosData->RSDTAddress.LowPart = Rsdp->rsdt_physical_address;
+        }
+
+        AcpiBiosData->Count = FreeldrDescCount;
+        memcpy(AcpiBiosData->MemoryMap, EfiMemoryMap,
+            FreeldrDescCount * sizeof(BIOS_MEMORY_MAP));
+
+        TRACE("RSDT %p, data size %x\n", Rsdp->rsdt_physical_address,
TableSize);
+
+        /* Create new bus key */
+        FldrCreateComponentKey(SystemKey,
+                               AdapterClass,
+                               MultiFunctionAdapter,
+                               0x0,
+                               0x0,
+                               0xFFFFFFFF,
+                               "ACPI BIOS",
+                               PartialResourceList,
+                               sizeof(CM_PARTIAL_RESOURCE_LIST) + TableSize,
+                               &BiosKey);
+
+        /* Increment bus number */
+        (*BusNumber)++;
+    }
+}
+
+PCONFIGURATION_COMPONENT_DATA
+UefiHwDetect(VOID)
+{
+    PCONFIGURATION_COMPONENT_DATA SystemKey;
+    ULONG BusNumber = 0;
+
+    TRACE("DetectHardware()\n");
+
+    /* Create the 'System' key */
+#if defined(_M_IX86) || defined(_M_AMD64)
+    FldrCreateSystemKey(&SystemKey, "AT/AT COMPATIBLE");
+#elif defined(_M_IA64)
+    FldrCreateSystemKey(&SystemKey, "Intel Itanium processor family");
+#elif defined(_M_ARM) || defined(_M_ARM64)
+    FldrCreateSystemKey(&SystemKey, "ARM processor family");
+#else
+    #error Please define a system key for your architecture
+#endif
+
+    /* Detect ACPI */
+    DetectAcpiBios(SystemKey, &BusNumber);
+
+    TRACE("DetectHardware() Done\n");
+    return SystemKey;
+}
diff --git a/boot/freeldr/freeldr/arch/uefi/uefildr.c
b/boot/freeldr/freeldr/arch/uefi/uefildr.c
index ef0dd85cba3..9f801d978a8 100644
--- a/boot/freeldr/freeldr/arch/uefi/uefildr.c
+++ b/boot/freeldr/freeldr/arch/uefi/uefildr.c
@@ -8,11 +8,16 @@
 #include <uefildr.h>
 
 #include <debug.h>
+DBG_DEFAULT_CHANNEL(WARNING);
 
 /* GLOBALS ********************************************************************/
 
 EFI_HANDLE GlobalImageHandle;
 EFI_SYSTEM_TABLE *GlobalSystemTable;
+PVOID UefiServiceStack;
+PVOID BasicStack;
+
+void _changestack(VOID);
 
 /* FUNCTIONS ******************************************************************/
 
@@ -25,15 +30,61 @@ EfiEntry(
     GlobalImageHandle = ImageHandle;
     GlobalSystemTable = SystemTable;
 
-    BootMain(NULL);
+    /* Needed for default settings */
+    CmdLineParse("");
+
+    /* Debugger pre-initialization */
+    DebugInit(0);
+
+    MachInit("");
+
+    /* UI pre-initialization */
+    if (!UiInitialize(FALSE))
+    {
+        UiMessageBoxCritical("Unable to initialize UI.");
+        goto Quit;
+    }
+
+    /* Initialize memory manager */
+    if (!MmInitializeMemoryManager())
+    {
+        UiMessageBoxCritical("Unable to initialize memory manager.");
+        goto Quit;
+    }
+
+    /* Initialize I/O subsystem */
+    FsInit();
+
+    /* 0x32000 is what UEFI defines, but we can go smaller if we want */
+    BasicStack = (PVOID)((ULONG_PTR)0x32000 +
(ULONG_PTR)MmAllocateMemoryWithType(0x32000, LoaderOsloaderStack));
+    _changestack();
+
+Quit:
+    /* If we reach this point, something went wrong before, therefore reboot */
+    Reboot();
 
     UNREACHABLE;
     return 0;
 }
 
+void
+ExecuteLoaderCleanly(PVOID PreviousStack)
+{
+    TRACE("ExecuteLoaderCleanly Entry\n");
+    UefiServiceStack = PreviousStack;
+
+    RunLoader();
+    UNREACHABLE;
+}
+
 #ifndef _M_ARM
 VOID __cdecl Reboot(VOID)
 {
-
+    //TODO: Replace with a true firmware reboot eventually
+    WARN("Something has gone wrong - halting FreeLoader\n");
+    for (;;)
+    {
+        NOTHING;
+    }
 }
 #endif
diff --git a/boot/freeldr/freeldr/arch/uefi/uefimem.c
b/boot/freeldr/freeldr/arch/uefi/uefimem.c
index 03a62150ef9..464b1f11783 100644
--- a/boot/freeldr/freeldr/arch/uefi/uefimem.c
+++ b/boot/freeldr/freeldr/arch/uefi/uefimem.c
@@ -27,6 +27,7 @@ AddMemoryDescriptor(
 
 /* GLOBALS *******************************************************************/
 
+extern ULONG LoaderPagesSpanned;
 extern EFI_SYSTEM_TABLE* GlobalSystemTable;
 extern EFI_HANDLE GlobalImageHandle;
 extern REACTOS_INTERNAL_BGCONTEXT framebufferData;
@@ -39,6 +40,8 @@ EFI_HANDLE PublicBootHandle;
 PVOID ExitStack;
 PVOID EndofExitStack;
 
+void _exituefi(VOID);
+
 /* FUNCTIONS *****************************************************************/
 
 static
@@ -85,56 +88,13 @@ VOID
 UefiSetMemory(
     _Inout_ PFREELDR_MEMORY_DESCRIPTOR MemoryMap,
     _In_ ULONG_PTR BaseAddress,
-    _In_ PFN_COUNT Size,
+    _In_ PFN_COUNT SizeInPages,
     _In_ TYPE_OF_MEMORY MemoryType)
 {
     ULONG_PTR BasePage, PageCount;
 
     BasePage = BaseAddress / EFI_PAGE_SIZE;
-    PageCount = Size;
-
-    /* Add the memory descriptor */
-    FreeldrDescCount = AddMemoryDescriptor(MemoryMap,
-                                           UNUSED_MAX_DESCRIPTOR_COUNT,
-                                           BasePage,
-                                           PageCount,
-                                           MemoryType);
-}
-
-VOID
-ReserveMemory(
-    _Inout_ PFREELDR_MEMORY_DESCRIPTOR MemoryMap,
-    _In_ ULONG_PTR BaseAddress,
-    _In_ PFN_NUMBER Size,
-    _In_ TYPE_OF_MEMORY MemoryType,
-    _In_ PCHAR Usage)
-{
-    ULONG_PTR BasePage, PageCount;
-    ULONG i;
-
-    BasePage = BaseAddress / PAGE_SIZE;
-    PageCount = ADDRESS_AND_SIZE_TO_SPAN_PAGES(BaseAddress, Size);
-
-    for (i = 0; i < FreeldrDescCount; i++)
-    {
-        /* Check for conflicting descriptor */
-        if ((MemoryMap[i].BasePage < BasePage + PageCount) &&
-            (MemoryMap[i].BasePage + MemoryMap[i].PageCount > BasePage))
-        {
-            /* Check if the memory is free */
-            if (MemoryMap[i].MemoryType != LoaderFree)
-            {
-                FrLdrBugCheckWithMessage(
-                    MEMORY_INIT_FAILURE,
-                    __FILE__,
-                    __LINE__,
-                    "Failed to reserve memory in the range 0x%Ix - 0x%Ix for
%s",
-                    BaseAddress,
-                    Size,
-                    Usage);
-            }
-        }
-    }
+    PageCount = SizeInPages;
 
     /* Add the memory descriptor */
     FreeldrDescCount = AddMemoryDescriptor(MemoryMap,
@@ -256,19 +216,36 @@ UefiMemGetMemoryMap(ULONG *MemoryMapSize)
             }
         }
 
-        UefiSetMemory(FreeldrMem,
-                      MapEntry->PhysicalStart,
-                      MapEntry->NumberOfPages,
-                      MemoryType);
+        /* Sometimes our loader can be loaded into higher memory than we ever allocate
*/
+        if (MemoryType == LoaderLoadedProgram)
+        {
+            if (((MapEntry->PhysicalStart + (MapEntry->NumberOfPages * PAGE_SIZE))
>> EFI_PAGE_SHIFT) > LoaderPagesSpanned)
+            {
+                /* This value needs to be adjusted if this occurs */
+                LoaderPagesSpanned = ((MapEntry->PhysicalStart +
(MapEntry->NumberOfPages * PAGE_SIZE)) >> EFI_PAGE_SHIFT);
+            }
+        }
+
+        /* We really don't want to touch these reserved spots at all */
+        if (MemoryType != LoaderReserve)
+        {
+            UefiSetMemory(FreeldrMem,
+                          MapEntry->PhysicalStart,
+                          MapEntry->NumberOfPages,
+                          MemoryType);
+        }
 
         MapEntry = NEXT_MEMORY_DESCRIPTOR(MapEntry, DescriptorSize);
     }
 
+    /* Windows expects the first page to be reserved, otherwise it asserts.
+     * However it can be just a free page on some UEFI systems. */
+    UefiSetMemory(FreeldrMem, 0x000000, 1, LoaderFirmwarePermanent);
     *MemoryMapSize = FreeldrDescCount;
     return FreeldrMem;
 }
 
-static VOID
+VOID
 UefiExitBootServices(VOID)
 {
     UINTN MapKey;
@@ -306,7 +283,5 @@ UefiExitBootServices(VOID)
 VOID
 UefiPrepareForReactOS(VOID)
 {
-    UefiExitBootServices();
-    ExitStack = MmAllocateMemoryWithType(EXIT_STACK_SIZE, LoaderOsloaderStack);
-    EndofExitStack = (PVOID)((ULONG_PTR)ExitStack + EXIT_STACK_SIZE);
+    _exituefi();
 }
diff --git a/boot/freeldr/freeldr/arch/uefi/uefisetup.c
b/boot/freeldr/freeldr/arch/uefi/uefisetup.c
index 01d1be758a1..ec3b0d405a6 100644
--- a/boot/freeldr/freeldr/arch/uefi/uefisetup.c
+++ b/boot/freeldr/freeldr/arch/uefi/uefisetup.c
@@ -14,7 +14,6 @@ DBG_DEFAULT_CHANNEL(WARNING);
 
 extern EFI_SYSTEM_TABLE* GlobalSystemTable;
 extern EFI_HANDLE GlobalImageHandle;
-BOOLEAN AcpiPresent = FALSE;
 
 /* FUNCTIONS ******************************************************************/
 
diff --git a/boot/freeldr/freeldr/uefi.cmake b/boot/freeldr/freeldr/uefi.cmake
index 76483f0529e..a3bc6a7e2e0 100644
--- a/boot/freeldr/freeldr/uefi.cmake
+++ b/boot/freeldr/freeldr/uefi.cmake
@@ -16,6 +16,7 @@ list(APPEND UEFILDR_ARC_SOURCE
     arch/uefi/stubs.c
     arch/uefi/ueficon.c
     arch/uefi/uefidisk.c
+    arch/uefi/uefihw.c
     arch/uefi/uefimem.c
     arch/uefi/uefisetup.c
     arch/uefi/uefiutil.c
@@ -23,11 +24,14 @@ list(APPEND UEFILDR_ARC_SOURCE
     arch/vgafont.c)
 
 if(ARCH STREQUAL "i386")
+    list(APPEND UEFILDR_ARC_SOURCE
+        arch/i386/i386idt.c)
     list(APPEND UEFILDR_COMMON_ASM_SOURCE
+        arch/uefi/i386/uefiasm.S
         arch/i386/i386trap.S)
-
 elseif(ARCH STREQUAL "amd64")
-    #TBD
+    list(APPEND UEFILDR_COMMON_ASM_SOURCE
+        arch/uefi/amd64/uefiasm.S)
 elseif(ARCH STREQUAL "arm")
     list(APPEND UEFILDR_ARC_SOURCE
         arch/arm/macharm.c
@@ -88,6 +92,11 @@ set_target_properties(uefildr PROPERTIES SUFFIX ".efi")
 
 target_compile_definitions(uefildr PRIVATE UEFIBOOT)
 
+# On AMD64 we only map 1GB with freeloader, tell UEFI to keep us low!
+if(ARCH STREQUAL "amd64")
+    set_image_base(uefildr 0x10000)
+endif()
+
 if(MSVC)
 if(NOT ARCH STREQUAL "arm")
     target_link_options(uefildr PRIVATE /DYNAMICBASE:NO)