Refactor IDT gate setup to use explicit DPL and type fields

Co-authored-by: Pedro Valadés <perikiyoxd@gmail.com>
Co-committed-by: Pedro Valadés <perikiyoxd@gmail.com>

boot/bootsect/CMakeLists.txt

@@ -1,6 +1,8 @@
 # XT Boot Sector
 PROJECT(BOOTSECT)
 
+add_definitions("-DARCH_ESP_SOURCE=\\\"${ARCH}/cpu.S\\\"")
+
 # Compile boot sectors
 compile_bootsector(mbrboot ${BOOTSECT_SOURCE_DIR}/mbrboot.S 0x7C00 Start)
 compile_bootsector(espboot ${BOOTSECT_SOURCE_DIR}/espboot.S 0x7C00 Start)

boot/bootsect/amd64/cpu.S

@@ -0,0 +1,144 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            boot/bootsect/amd64/cpu.S
+ * DESCRIPTION:     Low-level support for CPU initialization
+ * DEVELOPERS:      Aiken Harris <harraiken91@gmail.com>
+ */
+
+
+BuildPageMap:
+    /* Generate page map for first 1GB of memory */
+    pushaw
+    pushw %es
+    cld
+    movw $(0x1000 / 16), %ax
+    movw %ax, %es
+    xorw %di, %di
+    movl $(0x2000 | 0x07), %eax
+    stosl
+    xorl %eax, %eax
+    movw $1021, %cx
+    rep stosl
+    movw $(0x2000 / 16), %ax
+    movw %ax, %es
+    xorw %di, %di
+    movl $(0x3000 | 0x07), %eax
+    stosl
+    xorl %eax, %eax
+    movw $1021, %cx
+    rep stosl
+    movw $(0x3000 / 16), %ax
+    movw %ax, %es
+    xorw %di, %di
+    movw $512, %cx
+    movl $0x00000083, %eax
+.BuildPageMapLoop:
+    /* Identity map 512 pages of 2MB */
+    movl %eax, %es:(%di)
+    addl $2097152, %eax
+    addw $0x08, %di
+    loop .BuildPageMapLoop
+    popw %es
+    popaw
+    ret
+
+InitializeCpu:
+    /* Check if CPU supports CPUID, long mode and PAE */
+    pushal
+    pushfl
+    popl %eax
+    movl %eax, %ebx
+    xorl $0x00200000, %eax
+    pushl %eax
+    popfl
+    pushfl
+    popl %eax
+    cmpl %ebx, %eax
+    je CpuUnsupported
+    movl $0x01, %eax
+    cpuid
+    testl $0x40, %edx
+    jz CpuUnsupported
+    movl $0x80000000, %eax
+    cpuid
+    cmpl $0x80000000, %eax
+    jbe CpuUnsupported
+    movl $0x80000001, %eax
+    cpuid
+    testl $0x20000000, %edx
+    jz CpuUnsupported
+    popal
+    call LoadGdt
+    ret
+
+LoadGdt:
+    /* Load Global Descriptor Table */
+    lgdt .GdtPointer
+    ret
+
+RunStage2:
+    /* Switch to long mode and pass control to Stage 2 */
+    call BuildPageMap
+    call ParseExecutableHeader
+    xorl %edx, %edx
+    pushl %edx
+    pushl %eax
+    cli
+    xorw %ax, %ax
+    movw %ax, %ds
+    movw %ax, %es
+    movw %ax, %fs
+    movw %ax, %gs
+    movw %ax, %ss
+    movl %cr4, %eax
+    orl $0x00A0, %eax
+    movl %eax, %cr4
+    movl $0x00001000, %eax
+    movl %eax, %cr3
+    movl $0xC0000080, %ecx
+    rdmsr
+    orl $0x00000100, %eax
+    wrmsr
+    movl %cr0, %eax
+    orl $0x80000001, %eax
+    movl %eax, %cr0
+    ljmp $0x10, $.Stage2LongMode
+.code64
+.Stage2LongMode:
+    /* Set segments and stack, then jump to Stage 2 */
+    movw $0x18, %ax
+    movw %ax, %ds
+    movw %ax, %es
+    movw %ax, %ss
+    xorw %ax, %ax
+    movw %ax, %fs
+    movw %ax, %gs
+    popq %rax
+    xorq %rbx, %rbx
+    xorq %rcx, %rcx
+    xorq %rdx, %rdx
+    xorq %rsi, %rsi
+    xorq %rdi, %rdi
+    xorq %rbp, %rbp
+    jmp *%rax
+
+.code16
+.GdtDescriptor:
+    /* Global Descriptor Table */
+    .quad 0x0000000000000000
+    .quad 0x0000000000000000
+    .quad 0x00AF9A000000FFFF
+    .quad 0x00CF92000000FFFF
+    .quad 0x00009E000000FFFF
+    .quad 0x000092000000FFFF
+    .quad 0x00CF9B000000FFFF
+
+.GdtPointer:
+    /* Pointer to Global Descriptor Table */
+    .word .GdtPointer - .GdtDescriptor - 1
+    .long .GdtDescriptor
+
+.Stage2FileName:
+    /* Name of Stage 2 executable file */
+    .ascii "BOOTX64 EFI"

boot/bootsect/espboot.S

@@ -121,15 +121,15 @@ VerifyBiosParameterBlock:
     ja FsError
 
 ReadExtraCode:
-    /* Read second VBR sector with extra boot code */
+    /* Read second VBR sector with extra boot code (3 sectors starting from sector 2) */
     movl HiddenSectors - Start(%bp), %eax
     addl $0x02, %eax
-    movw $0x01, %cx
+    movw $0x03, %cx
     xorw %bx, %bx
     movw %bx, %es
     movw $0x7E00, %bx
     call ReadSectors
-    jmp StartSectors
+    jmp StartExtraCode
 
 ReadSectors:
     /* Check for extended BIOS functions and use it only if available */
@@ -139,18 +139,22 @@ ReadSectors:
     movw $0x55AA, %bx
     movb DriveNumber - Start(%bp), %dl
     int $0x13
-    jc ReadCHS
+    jc .ReadCHS
     cmpw $0xAA55, %bx
-    jne ReadCHS
+    jne .ReadCHS
     testb $0x01, %cl
-    jz ReadCHS
+    jz .ReadCHS
 
     /* Verify drive size and determine whether to use CHS or LBA */
     cmpl %edi, %eax
-    jnb ReadLBA
+    jnb .ReadLBA
 
-ReadCHS:
+.ReadCHS:
     /* Read sectors using CHS */
+    popal
+
+.CHSLoop:
+    /* Read sector by sector using CHS */
     pushw %cx
     pushal
     xorl %edx, %edx
@@ -176,11 +180,11 @@ ReadCHS:
     movw %es, %dx
     addw $0x20, %dx
     movw %dx, %es
-    loop ReadCHS
+    loop .CHSLoop
     popw %es
     ret
 
-ReadLBA:
+.ReadLBA:
     /* Prepare DAP packet and read sectors using LBA */
     popal
     pushw %cx
@@ -209,19 +213,19 @@ ReadLBA:
     movw %dx, %es
     popw %bx
     subw %si, %cx
-    jnz ReadLBA
+    jnz .ReadLBA
     popw %es
     ret
 
 DiskError:
     /* Display disk error message and reboot */
-    movw $msgDiskError, %si
+    movw $.MsgDiskError, %si
     call Print
     jmp Reboot
 
 FsError:
     /* Display FS error message and reboot */
-    movw $msgFsError, %si
+    movw $.MsgFsError, %si
     call Print
     jmp Reboot
 
@@ -229,48 +233,297 @@ Print:
     /* Simple routine to print messages */
     lodsb
     orb     %al, %al
-    jz      DonePrint
+    jz      .DonePrint
     movb    $0x0E, %ah
     movw    $0x07, %bx
     int     $0x10
     jmp     Print
-DonePrint:
+.DonePrint:
     retw
 
 Reboot:
     /* Display a message, wait for a key press and reboot */
-    movw $msgAnyKey, %si
+    movw $.MsgAnyKey, %si
     call Print
     xorw %ax, %ax
     int $0x16
     int $0x19
 
-msgAnyKey:
+.MsgAnyKey:
-    .ascii "Press any key to restart\r\n"
+    .ascii "Press any key to restart...\r\n\0"
 
-msgDiskError:
+.MsgDiskError:
-    .ascii "Disk error\r\n"
+    .ascii "Disk error!\r\n\0"
 
-msgFsError:
+.MsgFsError:
-    .ascii "File system error\r\n"
+    .ascii "File system error!\r\n\0"
 
 /* Fill the rest of the VBR with zeros and add VBR signature at the end */
 .fill (510 - (. - Start)), 1, 0
 .word 0xAA55
 
 
-StartSectors:
+StartExtraCode:
-    /* Print message */
+    /* Load XTLDR file from disk */
-    movw $msgUnavailable, %si
+    call LoadStage2
+
+    /* Enable A20 gate */
+    call EnableA20
+
+    /* Call architecture specific initialization code */
+    call InitializeCpu
+
+    /* Jump to Stage2 */
+    call RunStage2
+
+Clear8042:
+    /* Clear 8042 PS/2 buffer */
+    nop
+    nop
+    nop
+    nop
+    inb $0x64, %al
+    cmpb $0xff, %al
+    je .Clear8042_Done
+    testb $0x02, %al
+    jnz Clear8042
+.Clear8042_Done:
+    ret
+
+EnableA20:
+    /* Enable A20 gate */
+    pushaw
+    call Clear8042
+    movb $0xD1, %al
+    outb %al, $0x64
+    call Clear8042
+    movb $0xDF, %al
+    outb %al, $0x60
+    call Clear8042
+    movb $0xFF, %al
+    outb %al, $0x64
+    call Clear8042
+    popaw
+    ret
+
+FindFatEntry:
+    /* Find a file or directory in the FAT table */
+    pushw %bx
+    pushw %cx
+    pushw %dx
+    pushw %si
+    pushw %di
+.FindFatCluster:
+    /* Find FAT32 cluster holding the entry */
+    cmp $0x0FFFFFF8, %eax
+    jae .FindEntryFail
+    pushl %eax
+    movw $0x0200, %bx
+    movw %bx, %es
+    call ReadCluster
+    popl %eax
+    movb SectorsPerCluster - Start(%bp), %cl
+    shlw $0x04, %cx
+    xorw %di, %di
+.FindEntryLoop:
+    /* Find the entry */
+    movb %es:(%di), %al
+    cmpb $0x00, %al
+    je .FindEntryFail
+    cmpb $0xE5, %al
+    je .FindSkipEntry
+    movb %es:0x0B(%di), %ah
+    cmpb $0x0F, %ah
+    je .FindSkipEntry
+    pushw %di
+    pushw %si
+    pushw %cx
+    movw $0x0B, %cx
+    repe cmpsb
+    popw %cx
+    popw %si
+    popw %di
+    jnz .FindSkipEntry
+    movw %es:0x1A(%di), %ax
+    movw %es:0x14(%di), %dx
+    shll $0x10, %edx
+    orl %edx, %eax
+    clc
+    jmp .FindEntryDone
+.FindSkipEntry:
+    /* Skip to the next entry */
+    addw $0x20, %di
+    decw %cx
+    jnz .FindEntryLoop
+    call GetFatEntry
+    jmp .FindFatCluster
+.FindEntryFail:
+    /* Error, file/directory not found */
+    stc
+.FindEntryDone:
+    /* Clean up the stack */
+    popw %di
+    popw %si
+    popw %dx
+    popw %cx
+    popw %bx
+    ret
+
+GetFatEntry:
+    /* Get FAT32 sector and offset from FAT table */
+    shll $0x02, %eax
+    movl %eax, %ecx
+    xorl %edx, %edx
+    movzwl BytesPerSector - Start(%bp), %ebx
+    pushl %ebx
+    divl %ebx
+    movzwl ReservedSectors - Start(%bp), %ebx
+    addl %ebx, %eax
+    movl HiddenSectors - Start(%bp), %ebx
+    addl %ebx, %eax
+    popl %ebx
+    decl %ebx
+    andl %ebx, %ecx
+    movzwl ExtendedFlags - Start(%bp), %ebx
+    andw $0x0F, %bx
+    jz LoadFatSector
+    cmpb FatCopies - Start(%bp), %bl
+    jae FsError
+    pushl %eax
+    movl BigSectorsPerFat - Start(%bp), %eax
+    mull %ebx
+    popl %edx
+    addl %edx, %eax
+
+LoadFatSector:
+    /* Load FAT32 sector from disk */
+    pushl %ecx
+    movw $0x9000, %bx
+    movw %bx, %es
+    cmpl %esi, %eax
+    je .LoadFatSectorDone
+    movl %eax, %esi
+    xorw %bx, %bx
+    movw $0x01, %cx
+    call ReadSectors
+.LoadFatSectorDone:
+    /* Clean up the stack */
+    popl %ecx
+    movl %es:(%ecx), %eax
+    andl $0x0FFFFFFF, %eax
+    ret
+
+LoadStage2:
+    /* Load Stage2 executable, first find file in the path */
+    movl $0xFFFFFFFF, %esi
+    pushl %esi
+    movl 0x7C2C, %eax
+    movw $.EfiDirName, %si
+    call FindFatEntry
+    jc Stage2NotLoaded
+    movw $.BootDirName, %si
+    call FindFatEntry
+    jc Stage2NotLoaded
+    movw $.Stage2FileName, %si
+    call FindFatEntry
+    jc Stage2NotLoaded
+    popl %esi
+    /* Load XTLDR file from disk */
+    cmpl $0x02, %eax
+    jb FileNotFound
+    cmpl $0x0FFFFFF8, %eax
+    jae FileNotFound
+    movw $(0xF800 / 16), %bx
+    movw %bx, %es
+.LoadStage2Loop:
+    /* Load file data from disk */
+    pushl %eax
+    xorw %bx, %bx
+    pushw %es
+    call ReadCluster
+    popw %es
+    xorw %bx, %bx
+    movb SectorsPerCluster - Start(%bp), %bl
+    shlw $0x05, %bx
+    movw %es, %ax
+    addw %bx, %ax
+    movw %ax, %es
+    popl %eax
+    pushw %es
+    call GetFatEntry
+    popw %es
+    cmpl $0x0FFFFFF8, %eax
+    jb .LoadStage2Loop
+    ret
+
+ParseExecutableHeader:
+    /* Parse Stage2 PE/COFF executable header */
+    pushw %es
+    movw $(0xF800 / 16), %ax
+    movw %ax, %es
+    movl %es:60, %eax
+    addl $(4 + 20), %eax
+    movl %es:16(%eax), %eax
+    addl $0xF800, %eax
+    popw %es
+    ret
+
+ReadCluster:
+    /* Read FAT32 cluster from disk */
+    decl %eax
+    decl %eax
+    xorl %edx, %edx
+    movzbl SectorsPerCluster - Start(%bp), %ebx
+    mull %ebx
+    pushl %eax
+    xorl %edx, %edx
+    movzbl FatCopies - Start(%bp), %eax
+    mull BigSectorsPerFat - Start(%bp)
+    movzwl ReservedSectors - Start(%bp), %ebx
+    addl %ebx, %eax
+    addl HiddenSectors - Start(%bp), %eax
+    popl %ebx
+    addl %ebx, %eax
+    xorw %bx, %bx
+    movzbw SectorsPerCluster - Start(%bp), %cx
+    call ReadSectors
+    ret
+
+/* Include architecture specific code */
+.include ARCH_ESP_SOURCE
+
+CpuUnsupported:
+    /* Display CPU unsupported message and reboot */
+    popal
+    movw $.MsgCpuUnsupported, %si
     call Print
+    jmp Reboot
 
-    /* Wait for key press and reboot */
+FileNotFound:
-    xorw %ax, %ax
+    /* Display XTLDR not found message and reboot */
-    int $0x16
+    movw $.MsgXtLdrNotFound, %si
-    int $0x19
+    call Print
+    jmp Reboot
 
-msgUnavailable:
+Stage2NotLoaded:
-    .ascii "XTLDR requires EFI-based system!\r\nPress any key to restart\r\n"
+    /* Clean up the stack and display XTLDR not found message and reboot */
+    popl %esi
+    jmp FileNotFound
 
-/* Fill the rest of the extra VBR with zeros */
+.BootDirName:
-.fill (1024 - (. - Start)), 1, 0
+    /* Boot directory name */
+    .ascii "BOOT       "
+
+.EfiDirName:
+    /* EFI directory name */
+    .ascii "EFI        "
+
+.MsgCpuUnsupported:
+    .ascii "CPU not supported!\r\n\0"
+
+.MsgXtLdrNotFound:
+    .ascii "XTLDR Stage2 not found!\r\n\0"
+
+/* Fill the rest of the extra VBR with zeros and add signature */
+.fill (2043 - (. - Start)), 1, 0
+.ascii "XTLDR"

boot/bootsect/i686/cpu.S

@@ -0,0 +1,124 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            boot/bootsect/i686/cpu.S
+ * DESCRIPTION:     Low-level support for CPU initialization
+ * DEVELOPERS:      Aiken Harris <harraiken91@gmail.com>
+ */
+
+
+BuildPageMap:
+    /* Generate page map for first 16MB of memory */
+    pushaw
+    pushw %es
+    cld
+    movw $(0x1000 >> 0x04), %ax
+    movw %ax, %es
+    xorw %di, %di
+    movl $(0x2000 | 0x03), %eax
+    stosl
+    movl $(0x3000 | 0x03), %eax
+    stosl
+    movl $(0x4000 | 0x03), %eax
+    stosl
+    movl $(0x5000 | 0x03), %eax
+    stosl
+    xorl %eax, %eax
+    movw $(1024 - 4), %cx
+    rep stosl
+    movl $0x00000003, %eax
+    movl $4, %edx
+    movw $(0x2000 >> 0x04), %bx
+.BuildPageMapLoop:
+    /* Identity map 1024 pages of 4KB */
+    movw %bx, %es
+    xorw %di, %di
+    pushl %edx
+    movw $1024, %cx
+.FillPageMapTable:
+    /* Fill the page table */
+    movl %eax, %es:(%di)
+    addl $4096, %eax
+    addw $0x04, %di
+    loop .FillPageMapTable
+    popl %edx
+    addw $(0x1000 >> 0x04), %bx
+    decl %edx
+    jnz .BuildPageMapLoop
+    popw %es
+    popaw
+    ret
+
+InitializeCpu:
+    /* Check if CPU supports CPUID */
+    pushal
+    pushfl
+    popl %eax
+    movl %eax, %ebx
+    xorl $0x00200000, %eax
+    pushl %eax
+    popfl
+    pushfl
+    popl %eax
+    cmpl %ebx, %eax
+    je CpuUnsupported
+    popal
+    call LoadGdt
+    ret
+
+LoadGdt:
+    /* Load Global Descriptor Table */
+    lgdt .GdtPointer
+    ret
+
+RunStage2:
+    /* Switch to protected mode and pass control to Stage 2 */
+    call BuildPageMap
+    call ParseExecutableHeader
+    pushl %eax
+    cli
+    movl %cr0, %eax
+    orl $0x01, %eax
+    movl %eax, %cr0
+    ljmp $0x08, $.Stage2ProtectedMode
+.code32
+.Stage2ProtectedMode:
+    /* Set segments and stack, then jump to Stage 2 */
+    movw $0x10, %ax
+    movw %ax, %ds
+    movw %ax, %es
+    movw %ax, %ss
+    xorw %ax, %ax
+    movw %ax, %fs
+    movw %ax, %gs
+    popl %eax
+    xorl %ebx, %ebx
+    xorl %ecx, %ecx
+    xorl %edx, %edx
+    xorl %esi, %esi
+    xorl %edi, %edi
+    xorl %ebp, %ebp
+    movl $0x1000, %ebx
+    movl %ebx, %cr3
+    movl %cr0, %ebx
+    orl $0x80000000, %ebx
+    movl %ebx, %cr0
+    jmp *%eax
+
+.code16
+.GdtDescriptor:
+    /* Global Descriptor Table */
+    .quad 0x0000000000000000
+    .quad 0x00CF9A000000FFFF
+    .quad 0x00CF92000000FFFF
+    .quad 0x00009E000000FFFF
+    .quad 0x000092000000FFFF
+
+.GdtPointer:
+    /* Pointer to Global Descriptor Table */
+    .word .GdtPointer - .GdtDescriptor - 1
+    .long .GdtDescriptor
+
+.Stage2FileName:
+    /* Name of Stage 2 executable file */
+    .ascii "BOOTIA32EFI"

boot/bootsect/mbrboot.S

@@ -4,6 +4,7 @@
  * FILE:            boot/bootsect/amd64/mbrboot.S
  * DESCRIPTION:     XT Boot Loader MBR boot code
  * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ *                  Aiken Harris <aiken@codingworkshop.eu.org>
  */
 
 .text
@@ -41,7 +42,7 @@ RealStart:
     movw %ax, %ss
 
     /* Print welcome message */
-    leaw msgXtosBoot, %si
+    leaw .MsgXtosBoot, %si
     call Print
 
     /* Get BIOS boot drive and partition table offset */
@@ -90,19 +91,19 @@ PartitionFound:
 
 InvalidSignature:
     /* Invalid signature error */
-    leaw msgInvalidSignature, %si
+    leaw .MsgInvalidSignature, %si
     call Print
     jmp HaltSystem
 
 PartitionNotFound:
     /* Active partition not found error */
-    leaw msgPartitionNotFound, %si
+    leaw .MsgPartitionNotFound, %si
     call Print
     jmp HaltSystem
 
 VbrReadFail:
     /* VBR read failed error */
-    leaw msgVbrReadFail, %si
+    leaw .MsgVbrReadFail, %si
     call Print
     jmp HaltSystem
 
@@ -136,16 +137,16 @@ DonePrint:
     /* Storage for the LBA start */
     .long 0
 
-msgInvalidSignature:
+.MsgInvalidSignature:
     .asciz "Invalid partition signature!"
 
-msgPartitionNotFound:
+.MsgPartitionNotFound:
     .asciz "Bootable partition not found!"
 
-msgVbrReadFail:
+.MsgVbrReadFail:
     .asciz "VBR read failed!"
 
-msgXtosBoot:
+.MsgXtosBoot:
     .asciz "Starting XTOS boot loader...\r\n"
 
 /* Fill the rest of the MBR with zeros and add MBR signature at the end */

boot/xtldr/CMakeLists.txt

@@ -16,6 +16,7 @@ list(APPEND LIBXTLDR_SOURCE
 # Specify list of source code files
 list(APPEND XTLDR_SOURCE
     ${XTLDR_SOURCE_DIR}/arch/${ARCH}/memory.cc
+    ${XTLDR_SOURCE_DIR}/biosutil.cc
     ${XTLDR_SOURCE_DIR}/bootutil.cc
     ${XTLDR_SOURCE_DIR}/config.cc
     ${XTLDR_SOURCE_DIR}/console.cc
@@ -38,6 +39,9 @@ add_executable(xtldr ${XTLDR_SOURCE})
 # Add linker libraries
 target_link_libraries(xtldr libxtos)
 
+# Add linker options
+target_link_options(xtldr PRIVATE /ALIGN:512)
+
 # Set proper binary name and install target
 if(ARCH STREQUAL "i686")
 	set(BINARY_NAME "bootia32")
@@ -49,5 +53,6 @@ set_install_target(xtldr efi/boot)
 
 # Set loader entrypoint and subsystem
 set_entrypoint(xtldr "BlStartXtLoader")
+set_imagebase(xtldr ${BASEADDRESS_XTLDR})
 set_linker_map(xtldr TRUE)
 set_subsystem(xtldr efi_application)

boot/xtldr/biosutil.cc

@@ -0,0 +1,190 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtldr/biosutil.cc
+ * DESCRIPTION:     Legacy BIOS support
+ * DEVELOPERS:      Aiken Harris <harraiken91@gmail.com>
+ */
+
+#include <xtldr.hh>
+
+
+/**
+ * Clears the entire screen and moves the cursor to the top-left corner.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+VOID
+BiosUtils::ClearScreen()
+{
+    VOLATILE PUSHORT VgaBuffer = (PUSHORT)0xB8000;
+    USHORT Blank;
+    UINT Index;
+
+    /* Set blank character */
+    Blank = (0x0F << 8) | L' ';
+
+    /* Fill the entire screen with blank characters */
+    for(Index = 0; Index < VgaWidth * VgaHeight; Index++)
+    {
+        VgaBuffer[Index] = Blank;
+    }
+
+    /* Reset cursor position to the top-left corner */
+    CursorX = 0;
+    CursorY = 0;
+
+    /* Update the hardware cursor position */
+    UpdateCursor();
+}
+
+/**
+ * Formats the input string and prints it out to the screen.
+ *
+ * @param Format
+ *        The formatted string that is to be written to the output.
+ *
+ * @param ...
+ *        Depending on the format string, this routine might expect a sequence of additional arguments.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+VOID
+BiosUtils::Print(IN PCWSTR Format,
+                 IN ...)
+{
+    RTL_PRINT_CONTEXT PrintContext;
+    VA_LIST Arguments;
+
+    /* Initialise the print contexts */
+    PrintContext.WriteWideCharacter = PutChar;
+
+    /* Initialise the va_list */
+    VA_START(Arguments, Format);
+
+    /* Format and print the string to the stdout */
+    RTL::WideString::FormatWideString(&PrintContext, (PWCHAR)Format, Arguments);
+
+    /* Clean up the va_list */
+    VA_END(Arguments);
+}
+
+/**
+ * Writes a single wide character to the screen using legacy BIOS VGA text mode.
+ *
+ * @param Character
+ *        The wide character to be printed.
+ *
+ * @return This routine returns a status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+XTSTATUS
+BiosUtils::PutChar(IN WCHAR Character)
+{
+    VOLATILE PUSHORT VgaBuffer = (PUSHORT)0xB8000;
+    USHORT VgaCharacter;
+
+    /* Handle special characters */
+    if(Character == L'\n')
+    {
+        /* Move to the next line */
+        CursorX = 0;
+        CursorY++;
+    }
+    else if(Character == L'\r')
+    {
+        /* Move to the beginning of the current line */
+        CursorX = 0;
+    }
+    else
+    {
+        /* Print character and move cursor to the right */
+        VgaCharacter = (0x0F << 8) | (Character & 0xFF);
+        VgaBuffer[CursorY * VgaWidth + CursorX] = VgaCharacter;
+        CursorX++;
+    }
+
+    /* Handle moving to the next line if cursor is at the end of the line */
+    if(CursorX >= VgaWidth)
+    {
+        CursorX = 0;
+        CursorY++;
+    }
+
+    /* Handle scrolling if cursor is at the end of the screen */
+    if(CursorY >= VgaHeight)
+    {
+        ScrollScreen();
+        CursorY = VgaHeight - 1;
+    }
+
+    /* Update the hardware cursor position */
+    UpdateCursor();
+
+    /* Return success */
+    return STATUS_EFI_SUCCESS;
+}
+
+/**
+ * Scrolls the entire screen content up by one line and clears the last line.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+VOID
+BiosUtils::ScrollScreen()
+{
+    VOLATILE PUSHORT VgaBuffer = (PUSHORT)0xB8000;
+    USHORT Blank;
+    UINT Index;
+
+    /* Set blank character */
+    Blank = (0x0F << 8) | L' ';
+
+    /* Move every line up by one */
+    for(Index = 0; Index < (VgaHeight - 1) * VgaWidth; Index++)
+    {
+        VgaBuffer[Index] = VgaBuffer[Index + VgaWidth];
+    }
+
+    /* Clear the last line */
+    for(Index = (VgaHeight - 1) * VgaWidth; Index < VgaHeight * VgaWidth; Index++)
+    {
+        VgaBuffer[Index] = Blank;
+    }
+}
+
+/**
+ * Updates the hardware cursor position on the screen.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+VOID
+BiosUtils::UpdateCursor()
+{
+    USHORT Position;
+
+    /* Calculate cursor position */
+    Position = CursorY * VgaWidth + CursorX;
+
+    /* Send command to set the high byte of the cursor position */
+    HL::IoPort::WritePort8(0x3D4, 0x0E);
+    HL::IoPort::WritePort8(0x3D5, (UCHAR)((Position >> 8) & 0xFF));
+
+    /* Send command to set the low byte of the cursor position */
+    HL::IoPort::WritePort8(0x3D4, 0x0F);
+    HL::IoPort::WritePort8(0x3D5, (UCHAR)(Position & 0xFF));
+}

boot/xtldr/data.cc

@@ -10,6 +10,18 @@
 #include <xtldr.hh>
 
 
+/* Legacy BIOS cursor X position */
+USHORT BiosUtils::CursorX = 0;
+
+/* Legacy BIOS cursor Y position */
+USHORT BiosUtils::CursorY = 0;
+
+/* Legacy BIOS screen height */
+CONST USHORT BiosUtils::VgaHeight = 25;
+
+/* Legacy BIOS screen width */
+CONST USHORT BiosUtils::VgaWidth = 80;
+
 /* XT Boot Loader menu list */
 PLIST_ENTRY Configuration::BootMenuList = NULLPTR;
 

boot/xtldr/includes/xtldr.hh

@@ -15,6 +15,25 @@
 #include <libxtos.hh>
 
 
+class BiosUtils
+{
+    private:
+        STATIC USHORT CursorX;
+        STATIC USHORT CursorY;
+        STATIC CONST USHORT VgaHeight;
+        STATIC CONST USHORT VgaWidth;
+
+    public:
+        STATIC XTCDECL VOID ClearScreen();
+        STATIC XTCDECL VOID Print(IN PCWSTR Format,
+                                  IN ...);
+        STATIC XTCDECL XTSTATUS PutChar(IN WCHAR Character);
+
+    private:
+        STATIC XTCDECL VOID ScrollScreen();
+        STATIC XTCDECL VOID UpdateCursor();
+};
+
 class BootUtils
 {
     public:

boot/xtldr/xtldr.cc

@@ -236,6 +236,15 @@ BlStartXtLoader(IN EFI_HANDLE ImageHandle,
     PWCHAR Modules;
     EFI_STATUS Status;
 
+    /* Check if system is EFI-based and provided parameters are valid */
+    if(ImageHandle == NULLPTR || SystemTable == NULLPTR)
+    {
+        /* Invalid parameters, print error message using BIOS calls and hang */
+        BiosUtils::ClearScreen();
+        BiosUtils::Print(L"XTLDR requires EFI-based system!");
+        for(;;);
+    }
+
     /* Initialize XTLDR and */
     XtLoader::InitializeBootLoader(ImageHandle, SystemTable);
 

configure.ps1

@@ -4,48 +4,41 @@
 # DESCRIPTION: Project configuration script for preparing the build environment
 # DEVELOPERS:  Aiken Harris <harraiken91@gmail.com>
 
-
 # Check XTchain
 if (-not $env:XTCVER) {
-    Write-Host "XTChain not detected or corrupted!"
+    Write-Error "XTChain not detected or corrupted!"
     exit 1
 }
 
-# Set target architecture
+# Set target architecture defaulting to amd64
-if ($env:TARGET) {
+$ARCH = if ($env:TARGET) { $env:TARGET } else { "amd64" }
-    $ARCH = $env:TARGET
-} else {
-    $ARCH = "amd64"
-}
 
-# Set target build type
+# Set target build type defaulting to Debug
-if (-not $env:BUILD_TYPE) {
+$env:BUILD_TYPE = if ($env:BUILD_TYPE -in @("Debug", "Release")) { $env:BUILD_TYPE } else { "Debug" }
-    $env:BUILD_TYPE = "DEBUG"
-}
 
 # Set variables
-$EXECTOS_SOURCE_DIR = (Get-Location).Path
+$EXECTOS_SOURCE_DIR = $PSScriptRoot
-$EXECTOS_BINARY_DIR = "build-$($ARCH)-$($env:BUILD_TYPE.ToLower())"
+$EXECTOS_BINARY_DIR = Join-Path $EXECTOS_SOURCE_DIR "build-$ARCH-$($env:BUILD_TYPE.ToLower())"
 
-# Create directories if needed
+# Create build directory
-if ($EXECTOS_SOURCE_DIR -eq (Get-Location).Path) {
+if (-not (Test-Path $EXECTOS_BINARY_DIR)) {
-    Write-Host "Creating directories in $EXECTOS_BINARY_DIR"
+    Write-Host "Creating build directory: $EXECTOS_BINARY_DIR"
     New-Item -ItemType Directory -Path $EXECTOS_BINARY_DIR -Force | Out-Null
-    Set-Location -Path $EXECTOS_BINARY_DIR
 }
 
+Set-Location $EXECTOS_BINARY_DIR
+
 # Delete old cache
-Remove-Item -Path "CMakeCache.txt" -ErrorAction SilentlyContinue
+Remove-Item "CMakeCache.txt", "host-tools/CMakeCache.txt" -ErrorAction SilentlyContinue
-Remove-Item -Path "host-tools/CMakeCache.txt" -ErrorAction SilentlyContinue
 
 # Configure project using CMake
-& cmake -G Ninja -DARCH:STRING=$($ARCH) -DBUILD_TYPE:STRING=$($env:BUILD_TYPE) $EXECTOS_SOURCE_DIR
+& cmake -G Ninja "-DARCH:STRING=$ARCH" "-DBUILD_TYPE:STRING=$($env:BUILD_TYPE)" $EXECTOS_SOURCE_DIR
 
 # Check if configuration succeeded
 if ($LASTEXITCODE -ne 0) {
-    Write-Host "Configure script failed."
+    Write-Error "Configure script failed."
     exit 1
-} else {
-    "$($ARCH)" | Out-File -Encoding ASCII -NoNewline build.arch
-    Write-Host "Configure script completed. Enter '$EXECTOS_BINARY_DIR' directory and execute 'xbuild' to build ExectOS."
 }
+
+$ARCH | Out-File -Encoding ASCII -NoNewline "build.arch"
+Write-Host "Configure completed. Run 'xbuild' to build ExectOS."

sdk/cmake/baseaddress/amd64.cmake

@@ -1,2 +1,3 @@
 # Set base addresses for all modules
+set(BASEADDRESS_XTLDR    0x000000000000F800)
 set(BASEADDRESS_XTOSKRNL 0x0000000140000000)

sdk/cmake/baseaddress/i686.cmake

@@ -1,2 +1,3 @@
 # Set base addresses for all modules
+set(BASEADDRESS_XTLDR    0x0000F800)
 set(BASEADDRESS_XTOSKRNL 0x00400000)

sdk/cmake/functions.cmake

@@ -64,11 +64,17 @@ function(compile_bootsector NAME SOURCE BASEADDR ENTRYPOINT)
     set(BINARY_NAME "${NAME}.bin")
     set(OBJECT_NAME "${NAME}.obj")
 
+    get_directory_property(DEFS COMPILE_DEFINITIONS)
+    foreach(def ${DEFS})
+        list(APPEND ASM_DEFS "-D${def}")
+    endforeach()
+
     add_custom_command(
         OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${BINARY_NAME}
         COMMAND ${CMAKE_ASM_COMPILER}
             /nologo
             --target=i386-none-elf
+            ${ASM_DEFS}
             -I${CMAKE_CURRENT_SOURCE_DIR}
             /Fo${CMAKE_CURRENT_BINARY_DIR}/${OBJECT_NAME}
             -c -- ${SOURCE}

sdk/xtdk/amd64/ketypes.h

@@ -272,11 +272,18 @@ typedef struct _KIDTENTRY
 {
     USHORT OffsetLow;
     USHORT Selector;
+    union
+    {
+        struct
+        {
             USHORT IstIndex:3;
             USHORT Reserved0:5;
             USHORT Type:5;
             USHORT Dpl:2;
             USHORT Present:1;
+        };
+        USHORT Access;
+    };
     USHORT OffsetMiddle;
     ULONG OffsetHigh;
     ULONG Reserved1;

sdk/xtdk/i686/ketypes.h

@@ -58,12 +58,6 @@
 #define KIDT_ACCESS_RING0                 0x00
 #define KIDT_ACCESS_RING3                 0x60
 
-/* IDT gate types */
-#define KIDT_TASK                         0x05
-#define KIDT_CALL                         0x0C
-#define KIDT_INTERRUPT                    0x0E
-#define KIDT_TRAP                         0x0F
-
 /* TSS Offsets */
 #define KTSS_ESP0                         0x04
 #define KTSS_CR3                          0x1C
@@ -284,7 +278,18 @@ typedef struct _KIDTENTRY
 {
     USHORT Offset;
     USHORT Selector;
+    union
+    {
+        struct
+        {
+            UCHAR Reserved;
+            UCHAR Type:4;
+            UCHAR Flag:1;
+            UCHAR Dpl:2;
+            UCHAR Present:1;
+        };
         USHORT Access;
+    };
     USHORT ExtendedOffset;
 } KIDTENTRY, *PKIDTENTRY;
 

xtoskrnl/ar/amd64/procsup.cc

@@ -249,34 +249,34 @@ AR::ProcSup::InitializeIdt(IN PKPROCESSOR_BLOCK ProcessorBlock)
     for(Vector = 0; Vector < IDT_ENTRIES; Vector++)
     {
         /* Set the IDT to handle unexpected interrupts */
-        SetIdtGate(ProcessorBlock->IdtBase, Vector, (PVOID)ArTrap0xFF, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+        SetIdtGate(ProcessorBlock->IdtBase, Vector, (PVOID)ArTrap0xFF, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_INTERRUPT_GATE);
     }
 
     /* Setup IDT handlers for known interrupts and traps */
-    SetIdtGate(ProcessorBlock->IdtBase, 0x00, (PVOID)ArTrap0x00, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x00, (PVOID)ArTrap0x00, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x01, (PVOID)ArTrap0x01, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x01, (PVOID)ArTrap0x01, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x02, (PVOID)ArTrap0x02, KGDT_R0_CODE, KIDT_IST_PANIC, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x02, (PVOID)ArTrap0x02, KGDT_R0_CODE, KIDT_IST_PANIC, KIDT_ACCESS_RING0, AMD64_INTERRUPT_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x03, (PVOID)ArTrap0x03, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING3);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x03, (PVOID)ArTrap0x03, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING3, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x04, (PVOID)ArTrap0x04, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING3);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x04, (PVOID)ArTrap0x04, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING3, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x05, (PVOID)ArTrap0x05, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x05, (PVOID)ArTrap0x05, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x06, (PVOID)ArTrap0x06, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x06, (PVOID)ArTrap0x06, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x07, (PVOID)ArTrap0x07, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x07, (PVOID)ArTrap0x07, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x08, (PVOID)ArTrap0x08, KGDT_R0_CODE, KIDT_IST_PANIC, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x08, (PVOID)ArTrap0x08, KGDT_R0_CODE, KIDT_IST_PANIC, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x09, (PVOID)ArTrap0x09, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x09, (PVOID)ArTrap0x09, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x0A, (PVOID)ArTrap0x0A, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x0A, (PVOID)ArTrap0x0A, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x0B, (PVOID)ArTrap0x0B, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x0B, (PVOID)ArTrap0x0B, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x0C, (PVOID)ArTrap0x0C, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x0C, (PVOID)ArTrap0x0C, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x0D, (PVOID)ArTrap0x0D, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x0D, (PVOID)ArTrap0x0D, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x0E, (PVOID)ArTrap0x0E, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x0E, (PVOID)ArTrap0x0E, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x10, (PVOID)ArTrap0x10, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x10, (PVOID)ArTrap0x10, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x11, (PVOID)ArTrap0x11, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x11, (PVOID)ArTrap0x11, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x12, (PVOID)ArTrap0x12, KGDT_R0_CODE, KIDT_IST_MCA, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x12, (PVOID)ArTrap0x12, KGDT_R0_CODE, KIDT_IST_MCA, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x13, (PVOID)ArTrap0x13, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x13, (PVOID)ArTrap0x13, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x1F, (PVOID)ArTrap0x1F, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x1F, (PVOID)ArTrap0x1F, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_INTERRUPT_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x2C, (PVOID)ArTrap0x2C, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING3);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x2C, (PVOID)ArTrap0x2C, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING3, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x2D, (PVOID)ArTrap0x2D, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING3);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x2D, (PVOID)ArTrap0x2D, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING3, AMD64_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x2F, (PVOID)ArTrap0x2F, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x2F, (PVOID)ArTrap0x2F, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_INTERRUPT_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0xE1, (PVOID)ArTrap0xE1, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0xE1, (PVOID)ArTrap0xE1, KGDT_R0_CODE, KIDT_IST_RESERVED, KIDT_ACCESS_RING0, AMD64_INTERRUPT_GATE);
 }
 
 /**
@@ -636,6 +636,9 @@ AR::ProcSup::SetGdtEntryBase(IN PKGDTENTRY Gdt,
  * @param Access
  *        Supplies the gate access rights.
  *
+ * @param Type
+ *        Supplies the gate type.
+ *
  * @return This routine does not return any value.
  *
  * @since XT 1.0
@@ -647,15 +650,22 @@ AR::ProcSup::SetIdtGate(IN PKIDTENTRY Idt,
                         IN PVOID Handler,
                         IN USHORT Selector,
                         IN USHORT Ist,
-                        IN USHORT Access)
+                        IN USHORT Dpl,
+                        IN USHORT Type)
 {
-    /* Setup the gate */
+    /* Set the handler's address */
     Idt[Vector].OffsetLow = ((ULONG_PTR)Handler & 0xFFFF);
     Idt[Vector].OffsetMiddle = (((ULONG_PTR)Handler >> 16) & 0xFFFF);
     Idt[Vector].OffsetHigh = (ULONG_PTR)Handler >> 32;
-    Idt[Vector].Dpl = Access;
+
+    /* Set the code segment selector */
+    Idt[Vector].Selector = Selector;
+
+    /* Initialize the gate's attributes and flags */
+    Idt[Vector].Access = 0;
+    Idt[Vector].Dpl = Dpl;
     Idt[Vector].IstIndex = Ist;
     Idt[Vector].Present = 1;
-    Idt[Vector].Selector = Selector;
+    Idt[Vector].Reserved1 = 0;
-    Idt[Vector].Type = 0xE;
+    Idt[Vector].Type = Type;
 }

xtoskrnl/ar/i686/procsup.cc

@@ -242,34 +242,34 @@ AR::ProcSup::InitializeIdt(IN PKPROCESSOR_BLOCK ProcessorBlock)
     for(Vector = 0; Vector < IDT_ENTRIES; Vector++)
     {
         /* Set the IDT to handle unexpected interrupts */
-        SetIdtGate(ProcessorBlock->IdtBase, Vector, (PVOID)ArTrap0xFF, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+        SetIdtGate(ProcessorBlock->IdtBase, Vector, (PVOID)ArTrap0xFF, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_INTERRUPT_GATE);
     }
 
     /* Setup IDT handlers for known interrupts and traps */
-    SetIdtGate(ProcessorBlock->IdtBase, 0x00, (PVOID)ArTrap0x00, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x00, (PVOID)ArTrap0x00, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x01, (PVOID)ArTrap0x01, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x01, (PVOID)ArTrap0x01, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x02, (PVOID)ArTrap0x02, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x02, (PVOID)ArTrap0x02, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_INTERRUPT_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x03, (PVOID)ArTrap0x03, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING3);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x03, (PVOID)ArTrap0x03, KGDT_R0_CODE, 0, KIDT_ACCESS_RING3, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x04, (PVOID)ArTrap0x04, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING3);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x04, (PVOID)ArTrap0x04, KGDT_R0_CODE, 0, KIDT_ACCESS_RING3, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x05, (PVOID)ArTrap0x05, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x05, (PVOID)ArTrap0x05, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x06, (PVOID)ArTrap0x06, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x06, (PVOID)ArTrap0x06, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x07, (PVOID)ArTrap0x07, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x07, (PVOID)ArTrap0x07, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x08, (PVOID)ArTrap0x08, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x08, (PVOID)ArTrap0x08, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x09, (PVOID)ArTrap0x09, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x09, (PVOID)ArTrap0x09, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x0A, (PVOID)ArTrap0x0A, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x0A, (PVOID)ArTrap0x0A, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x0B, (PVOID)ArTrap0x0B, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x0B, (PVOID)ArTrap0x0B, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x0C, (PVOID)ArTrap0x0C, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x0C, (PVOID)ArTrap0x0C, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x0D, (PVOID)ArTrap0x0D, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x0D, (PVOID)ArTrap0x0D, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x0E, (PVOID)ArTrap0x0E, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x0E, (PVOID)ArTrap0x0E, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x10, (PVOID)ArTrap0x10, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x10, (PVOID)ArTrap0x10, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x11, (PVOID)ArTrap0x11, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x11, (PVOID)ArTrap0x11, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x12, (PVOID)ArTrap0x12, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x12, (PVOID)ArTrap0x12, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x13, (PVOID)ArTrap0x13, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING0);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x13, (PVOID)ArTrap0x13, KGDT_R0_CODE, 0, KIDT_ACCESS_RING0, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x2A, (PVOID)ArTrap0x2A, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING3);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x2A, (PVOID)ArTrap0x2A, KGDT_R0_CODE, 0, KIDT_ACCESS_RING3, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x2B, (PVOID)ArTrap0x2B, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING3);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x2B, (PVOID)ArTrap0x2B, KGDT_R0_CODE, 0, KIDT_ACCESS_RING3, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x2C, (PVOID)ArTrap0x2C, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING3);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x2C, (PVOID)ArTrap0x2C, KGDT_R0_CODE, 0, KIDT_ACCESS_RING3, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x2D, (PVOID)ArTrap0x2D, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING3);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x2D, (PVOID)ArTrap0x2D, KGDT_R0_CODE, 0, KIDT_ACCESS_RING3, I686_TRAP_GATE);
-    SetIdtGate(ProcessorBlock->IdtBase, 0x2E, (PVOID)ArTrap0x2E, KGDT_R0_CODE, 0, KIDT_INTERRUPT | KIDT_ACCESS_RING3);
+    SetIdtGate(ProcessorBlock->IdtBase, 0x2E, (PVOID)ArTrap0x2E, KGDT_R0_CODE, 0, KIDT_ACCESS_RING3, I686_TRAP_GATE);
 }
 
 /**
@@ -656,6 +656,9 @@ AR::ProcSup::SetGdtEntryBase(IN PKGDTENTRY Gdt,
  * @param Access
  *        Supplies the gate access rights.
  *
+ * @param Type
+ *        Supplies the gate type.
+ *
  * @return This routine does not return any value.
  *
  * @since XT 1.0
@@ -667,13 +670,21 @@ AR::ProcSup::SetIdtGate(IN PKIDTENTRY Idt,
                         IN PVOID Handler,
                         IN USHORT Selector,
                         IN USHORT Ist,
-                        IN USHORT Access)
+                        IN USHORT Dpl,
+                        IN USHORT Type)
 {
-    /* Setup the gate */
+    /* Set the handler's address */
     Idt[Vector].Offset = (USHORT)((ULONG)Handler & 0xFFFF);
     Idt[Vector].ExtendedOffset = (USHORT)((ULONG)Handler >> 16);
-    Idt[Vector].Access = 0x8000 | (Access << 8);
+
+    /* Set the code segment selector */
     Idt[Vector].Selector = Selector;
+
+    /* Initialize the gate's attributes and flags */
+    Idt[Vector].Access = 0;
+    Idt[Vector].Dpl = Dpl;
+    Idt[Vector].Present = 1;
+    Idt[Vector].Type = Type;
 }
 
 /**

xtoskrnl/includes/ar/amd64/procsup.hh

@@ -67,7 +67,8 @@ namespace AR
                                          IN PVOID Handler,
                                          IN USHORT Selector,
                                          IN USHORT Ist,
-                                         IN USHORT Access);
+                                         IN USHORT Dpl,
+                                         IN USHORT Type);
     };
 }
 

xtoskrnl/includes/ar/i686/procsup.hh

@@ -72,7 +72,8 @@ namespace AR
                                          IN PVOID Handler,
                                          IN USHORT Selector,
                                          IN USHORT Ist,
-                                         IN USHORT Access);
+                                         IN USHORT Dpl,
+                                         IN USHORT Type);
             STATIC XTAPI VOID SetNonMaskableInterruptTssEntry(IN PKPROCESSOR_BLOCK ProcessorBlock,
                                                               IN PVOID KernelFaultStack);