[FREELDR] Re-integrate the ASM files (and corresponding C code) in MSVC builds, that were previously compiled just for GCC builds. (#1224)

- Multiboot support added back in FreeLdr MSVC builds so that it can be
  booted using e.g. GRUB. See CORE-15563.

- Re-introduce the disk drive mapper code.

boot/freeldr/freeldr/CMakeLists.txt

@@ -159,14 +159,19 @@ list(APPEND FREELDR_BOOTMGR_SOURCE
     video/palette.c
     video/video.c)
 
+list(APPEND FREELDR_BASE_ASM_SOURCE)
+
 if(ARCH STREQUAL "i386")
+    list(APPEND FREELDR_BASE_ASM_SOURCE
+        arch/i386/multiboot.S)
+
     list(APPEND FREELDR_COMMON_ASM_SOURCE
+        arch/i386/drvmap.S
         arch/i386/entry.S
         arch/i386/int386.S
         arch/i386/pnpbios.S
         arch/i386/i386trap.S
-        arch/i386/linux.S
+        arch/i386/linux.S)
-        arch/i386/mb.S)
 
     list(APPEND FREELDR_NTLDR_SOURCE
         ntldr/arch/i386/winldr.c
@@ -202,9 +207,6 @@ if(ARCH STREQUAL "i386")
         arch/i386/xboxrtc.c
         arch/i386/xboxvideo.c
         disk/scsiport.c)
-    if(NOT MSVC)
-        list(APPEND FREELDR_COMMON_ASM_SOURCE arch/i386/drvmap.S)
-    endif()
 
 elseif(ARCH STREQUAL "amd64")
     list(APPEND FREELDR_COMMON_ASM_SOURCE
@@ -271,13 +273,15 @@ set(PCH_SOURCE
 add_pch(freeldr_common include/freeldr.h PCH_SOURCE)
 add_dependencies(freeldr_common bugcodes asm xdk)
 
-if(ARCH STREQUAL "i386" AND NOT MSVC)
-    list(APPEND FREELDR_BASE_SOURCE arch/i386/multiboot.S)
 ## GCC builds need this extra thing for some reason...
+if(ARCH STREQUAL "i386" AND NOT MSVC)
     target_link_libraries(freeldr_common mini_hal)
 endif()
 
+add_asm_files(freeldr_base_asm ${FREELDR_BASE_ASM_SOURCE})
+
 list(APPEND FREELDR_BASE_SOURCE
+    ${freeldr_base_asm}
     bootmgr.c # This file is compiled with custom definitions
     freeldr.c
     ntldr/setupldr.c ## Strangely enough this file is needed in GCC builds

boot/freeldr/freeldr/arch/i386/drivemap.c

@@ -20,21 +20,20 @@
 #include <freeldr.h>
 #include <debug.h>
 
-DBG_DEFAULT_CHANNEL(WARNING);
+DBG_DEFAULT_CHANNEL(DISK);
 
 BOOLEAN      DriveMapInstalled = FALSE;    // Tells us if we have already installed our drive map int 13h handler code
 ULONG        OldInt13HandlerAddress = 0;   // Address of BIOS int 13h handler
 ULONG        DriveMapHandlerAddress = 0;   // Linear address of our drive map handler
 ULONG        DriveMapHandlerSegOff = 0;    // Segment:offset style address of our drive map handler
 
-#ifndef _MSC_VER
 VOID DriveMapMapDrivesInSection(PCSTR SectionName)
 {
     CHAR           SettingName[80];
     CHAR           SettingValue[80];
     CHAR           Drive1[80];
     CHAR           Drive2[80];
-    ULONG          SectionId;
+    ULONG_PTR      SectionId;
     ULONG          SectionItemCount;
     ULONG          Index;
     ULONG          Index2;
@@ -143,7 +142,6 @@ BOOLEAN DriveMapIsValidDriveString(PCSTR DriveString)
 
     return TRUE;
 }
-#endif
 
 UCHAR DriveMapGetBiosDriveNumber(PCSTR DeviceName)
 {
@@ -172,7 +170,6 @@ UCHAR DriveMapGetBiosDriveNumber(PCSTR DeviceName)
     return BiosDriveNumber;
 }
 
-#ifndef _MSC_VER
 VOID DriveMapInstallInt13Handler(PDRIVE_MAP_LIST DriveMap)
 {
     ULONG*  RealModeIVT = (ULONG*)0x00000000;
@@ -226,4 +223,3 @@ VOID DriveMapRemoveInt13Handler(VOID)
         DriveMapInstalled = FALSE;
     }
 }
-#endif

boot/freeldr/freeldr/arch/i386/drvmap.S

@@ -17,7 +17,6 @@
  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-
 #include <asm.inc>
 #include <arch/pc/x86common.h>
 
@@ -25,8 +24,8 @@
 
 PUBLIC _DriveMapInt13HandlerStart
 _DriveMapInt13HandlerStart:
-Int13Handler:
 
+Int13Handler:
     push bp
     mov bp, sp
     push ax
@@ -40,14 +39,14 @@ Int13Handler:
     mov word ptr cs:[CallersFlags - Int13Handler], ax
 
     /* Save the drive number they passed in */
-    mov cs:[PassedInDriveNumber - Int13Handler], dl
+    mov byte ptr cs:[PassedInDriveNumber - Int13Handler], dl
 
     /* Now we need to perform the mapping */
     xor cx, cx
     mov si, offset Int13HandlerMapCount - Int13Handler
 
     /* Get the count of drives in the map list */
-    mov cl, cs:[si]
+    mov cl, byte ptr cs:[si]
     inc si
 
     /* If the map list is empty then just call the old int 13h handler */
@@ -56,8 +55,8 @@ Int13Handler:
 
 GetMappedDriveNumberLoop:
 
-    /* Get the next drive number in the list */
+    /* Get the next drive number in the list (store it in AX) */
-    lods ax, cs:[si]
+    lods word ptr cs:[si]
 
     /* Check to see if it's the one they are calling int 13h for */
     cmp dl, al
@@ -84,7 +83,6 @@ CallOldInt13Handler:
     /* Put flags onto stack */
     push word ptr cs:[CallersFlags - Int13Handler]
 
-
     /* Call old int 13h handler with new drive number */
     .byte HEX(9a) /* lcall */
 PUBLIC _DriveMapOldInt13HandlerAddress
@@ -100,7 +98,7 @@ _DriveMapOldInt13HandlerAddress:
     pop ax
 
     /* Restore the callers drive number */
-    mov dl, cs:[PassedInDriveNumber - Int13Handler]
+    mov dl, byte ptr cs:[PassedInDriveNumber - Int13Handler]
 
     pop bp
 
@@ -112,6 +110,7 @@ CallersFlags:
 PassedInDriveNumber:
     .byte   0
 
+/* See the DRIVE_MAP_LIST structure in include/arch/i386/drivemap.h */
 PUBLIC _DriveMapInt13HandlerMapList
 _DriveMapInt13HandlerMapList:
 Int13HandlerMapCount:
@@ -139,3 +138,7 @@ Int13HandlerDriveNew4:
 
 PUBLIC _DriveMapInt13HandlerEnd
 _DriveMapInt13HandlerEnd:
+
+.endcode16
+
+END

boot/freeldr/freeldr/arch/i386/entry.S

@@ -25,7 +25,7 @@ EXTERN _BootMain:PROC
 EXTERN _InitIdt:PROC
 EXTERN _i386Idt:DWORD
 //EXTERN _i386idtptr:FWORD
-// EXTERN cmdline:DWORD
+EXTERN cmdline:DWORD
 
 #ifdef _USE_ML
 EXTERN __bss_start__:DWORD
@@ -89,8 +89,7 @@ ASSUME /*CS:_TEXT,*/ DS:_DATA, ES:_DATA, FS:_DATA, GS:_DATA, SS:_DATA
     call _InitIdt
 
     /* Pass the command line to BootMain */
-    // mov eax, offset cmdline
+    mov eax, offset cmdline
-    xor eax, eax
 
     /* GO! */
     push eax

boot/freeldr/freeldr/arch/i386/mb.S

@@ -1,51 +0,0 @@
-/*
- *  FreeLoader
- *  Copyright (C) 1998-2002  Brian Palmer  <brianp@sginet.com>
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License along
- *  with this program; if not, write to the Free Software Foundation, Inc.,
- *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-#include <asm.inc>
-#include <arch/pc/x86common.h>
-#include <multiboot.h>
-
-.code32
-PUBLIC _PageDirectoryStart
-
-PUBLIC _startup_pagedirectory
-PUBLIC _lowmem_pagetable
-PUBLIC _kernel_pagetable
-PUBLIC _apic_pagetable
-PUBLIC _PageDirectoryEnd
-
-#ifndef _USE_ML
-.bss
-#endif
-_PageDirectoryStart:
-_startup_pagedirectory:
-    .fill 4096, 1, 0
-
-_lowmem_pagetable:
-    .fill 4096, 1, 0
-
-_kernel_pagetable:
-    .fill 2*4096, 1, 0
-
-_apic_pagetable:
-    .fill 4096, 1, 0
-
-_PageDirectoryEnd:
-
-END

boot/freeldr/freeldr/arch/i386/multiboot.S

@@ -42,6 +42,18 @@
  */
 #define INITIAL_BASE HEX(200000)
 
+
+#ifdef _USE_ML
+EXTERN __bss_start__:DWORD
+EXTERN __bss_end__:DWORD
+#endif
+
+
+#ifdef _USE_ML
+.MBDATA SEGMENT PUBLIC 'DATA'
+ASSUME nothing
+#endif
+
     /* Align to 32 bits boundary */
     .align 4
 
@@ -54,7 +66,7 @@ MultibootHeader:
     /* checksum */
     .long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS)
     /* header_addr */
-    .long INITIAL_BASE + MultibootHeader - FREELDR_BASE
+    .long MultibootHeader + INITIAL_BASE - FREELDR_BASE
     /* load_addr */
     .long INITIAL_BASE
     /* load_end_addr */
@@ -62,15 +74,27 @@ MultibootHeader:
     /* bss_end_addr */
     .long 0
     /* entry_addr */
-    .long INITIAL_BASE + MultibootEntry - FREELDR_BASE
+    .long MultibootEntry + INITIAL_BASE - FREELDR_BASE
+
+#ifdef _USE_ML
+.MBDATA ENDS
+#endif
+
+
+.code32
+ASSUME ES:NOTHING, FS:NOTHING, GS:NOTHING
 
 MultibootEntry:
     cld
 
+    /* Check for valid multiboot signature */
+    cmp eax, MULTIBOOT_BOOTLOADER_MAGIC
+    jne mbfail
+
     /* Save command line */
-    test dword ptr [ebx + MB_INFO_FLAGS_OFFSET], MB_INFO_FLAG_COMMAND_LINE
+    test dword ptr ds:[ebx + MB_INFO_FLAGS_OFFSET], MB_INFO_FLAG_COMMAND_LINE
     jz mb2
-    mov esi, [ebx + MB_INFO_COMMAND_LINE_OFFSET]
+    mov esi, dword ptr ds:[ebx + MB_INFO_COMMAND_LINE_OFFSET]
     mov edi, offset cmdline + INITIAL_BASE - FREELDR_BASE
     mov ecx, CMDLINE_SIZE - 1
 mb1:
@@ -83,14 +107,14 @@ mb1:
 
 mb2:
     /* See if the boot device was passed in */
-    test dword ptr [ebx + MB_INFO_FLAGS_OFFSET], MB_INFO_FLAG_BOOT_DEVICE
+    test dword ptr ds:[ebx + MB_INFO_FLAGS_OFFSET], MB_INFO_FLAG_BOOT_DEVICE
 
     /* If no boot device known, assume first partition of first harddisk */
     mov dx, HEX(0180)
     jz mb3
 
     /* Load boot drive into DL, boot partition into DH */
-    mov edx, [ebx + MB_INFO_BOOT_DEVICE_OFFSET]
+    mov edx, dword ptr ds:[ebx + MB_INFO_BOOT_DEVICE_OFFSET]
     bswap edx
     inc dh
 
@@ -103,7 +127,11 @@ mb3:
     rep movsd
 
     /* Load segment registers for real-address mode */
-    lgdt gdtptr
+#ifdef _USE_ML
+    lgdt fword ptr ds:[gdtptr]
+#else
+    lgdt ds:[gdtptr]
+#endif
     mov ax, HEX(10)
     mov ds, ax
     mov es, ax
@@ -114,6 +142,11 @@ mb3:
     /* Jump to relocated code */
     ljmp HEX(08), mb4
 
+mbfail:
+    int 3
+mbstop:
+    jmp short mbstop  /* We should never get here */
+
 .code16
 mb4:
     /* Disable protected mode */
@@ -123,26 +156,20 @@ mb4:
 
     /* Jump to real entry point */
     ljmp16 0, FREELDR_BASE
+.endcode16
+
 
     /* Force 8-byte alignment */
     .align 8
 gdt:
-    /* 16-bit flat CS (!) */
+    .word HEX(0000), HEX(0000), HEX(0000), HEX(0000) /* 00: NULL descriptor */
-    .word HEX(FFFF)
+    .word HEX(FFFF), HEX(0000), HEX(9B00), HEX(008F) /* 08: 16-bit flat CS (!) */
-    .word HEX(0000)
+    .word HEX(FFFF), HEX(0000), HEX(9300), HEX(0000) /* 10: 16-bit real mode DS */
-    .word HEX(9B00)
-    .word HEX(008F)
 
-    /* 16-bit real mode DS */
+/* GDT table pointer */
-    .word HEX(FFFF)
-    .word HEX(0000)
-    .word HEX(9300)
-    .word HEX(0000)
-
-    /* GDT pointer */
 gdtptr:
     .word HEX(17)   /* Limit */
-    .long gdt - 8       /* Base Address */
+    .long gdt       /* Base Address */
 
 PUBLIC cmdline
 cmdline:

boot/freeldr/freeldr/bootmgr.c

@@ -88,8 +88,8 @@ VOID LoadOperatingSystem(IN OperatingSystemItem* OperatingSystem)
         }
     }
 
+#if defined(_M_IX86)
     /* Install the drive mapper according to this section drive mappings */
-#if defined(_M_IX86) && !defined(_MSC_VER)
     DriveMapMapDrivesInSection(SectionName);
 #endif
 

boot/freeldr/freeldr/freeldr_i386.msvc.lds

@@ -32,7 +32,7 @@
  *   Otherwise they are kept separated, unless an explicit /MERGE is used.
  */
 
-#pragma comment(linker, "/SECTION:.text,ERW /SECTION:.data,RW /MERGE:INIT=.text /MERGE:.edata=.rdata")
+#pragma comment(linker, "/SECTION:.text,ERW /SECTION:.data,RW /MERGE:.MBDATA=.text /MERGE:INIT=.text /MERGE:.edata=.rdata")
 
 #endif
 

boot/freeldr/freeldr/include/arch/pc/x86common.h

@@ -77,6 +77,3 @@
 #define LMODE_DS HEX(18)
 #define CMODE_CS HEX(30)
 //#endif
-
-/* Makes "x" a global variable or label */
-#define EXTERN(x)    .global x; x: