EXTERN _InitIdt:PROC
EXTERN _i386Idt:DWORD
//EXTERN _i386idtptr:FWORD
+EXTERN cmdline:DWORD
+
+EXTERN _DiskStopFloppyMotor:PROC
+
+#ifdef _USE_ML
+EXTERN __bss_start__:DWORD
+EXTERN __bss_end__:DWORD
+#endif
.code32
PUBLIC _RealEntryPoint
_RealEntryPoint:
- /* Setup segment selectors */
- mov ax, PMODE_DS
- mov ds, ax
- mov es, ax
- mov fs, ax
- mov gs, ax
- mov ss, ax
+ /* Setup segment selectors */
+ mov ax, PMODE_DS
+ mov ds, ax
+ mov es, ax
+ mov fs, ax
+ mov gs, ax
+ mov ss, ax
/* Setup protected mode stack */
- mov esp, dword ptr ds:[stack32]
+ mov esp, dword ptr ds:[stack32]
- /* Load the IDT */
+ /* Load the IDT */
#ifdef _USE_ML
lidt fword ptr ds:[i386idtptr]
#else
- lidt i386idtptr
+ lidt i386idtptr
#endif
/* Continue execution */
jmp dword ptr ds:[ContinueAddress]
+PUBLIC ContinueAddress
ContinueAddress:
.long _FrldrStartup
-
_FrldrStartup:
/* Store BootDrive and BootPartition */
- mov byte ptr ds:[_FrldrBootDrive], dl
- xor eax, eax
+ mov byte ptr ds:[_FrldrBootDrive], dl
+ xor eax, eax
mov al, dh
- mov dword ptr ds:[_FrldrBootPartition], eax
+ mov dword ptr ds:[_FrldrBootPartition], eax
/* Patch long jump with real mode entry point */
mov eax, dword ptr ds:[BSS_RealModeEntry]
mov dword ptr ds:[SwitchToReal16Address], eax
- /* Initialize the idt */
- call _InitIdt
-
-#ifndef _USE_ML
- /* Clean out bss */
+ /* Clean out BSS */
xor eax, eax
mov edi, offset __bss_start__
mov ecx, offset __bss_end__ + 3
shr ecx, 2
rep stosd
+ /* Initialize the idt */
+ call _InitIdt
+
/* Pass the command line to BootMain */
mov eax, offset cmdline
-#else
- xor eax, eax
-#endif
- /* GO! */
- push eax
- call _BootMain
+ /* GO! */
+ push eax
+ call _BootMain
- /* We should never get here */
+ /* We should never get here */
stop:
- jmp stop
- nop
- nop
+ jmp short stop
+ nop
+ nop
+
+
+PUBLIC _Reboot
+_Reboot:
+ /* Stop the floppy drive motor */
+ call _DiskStopFloppyMotor
+
+ /* Set the function ID and switch to real mode (we don't return) */
+ mov bx, FNID_Reboot
+ jmp SwitchToReal
-Int386_regsin:
- .long 0
-Int386_regsout:
- .long 0
/*
- * int Int386(int ivec, REGS* in, REGS* out);
+ * VOID __cdecl Relocator16Boot(
+ * IN REGS* In,
+ * IN USHORT StackSegment,
+ * IN USHORT StackPointer,
+ * IN USHORT CodeSegment,
+ * IN USHORT CodePointer);
+ *
+ * RETURNS: Nothing.
+ *
+ * NOTE: The implementation of this function is similar to that of Int386(),
+ * with the proviso that no attempt is done to save the original values of
+ * the registers since we will not need them anyway, as we do not return back
+ * to the caller but instead place the machine in a permanent new CPU state.
*/
-PUBLIC _Int386
-_Int386:
-
- /* Get the function parameters */
- mov eax, dword ptr [esp + 4]
- mov dword ptr ds:[BSS_IntVector], eax
- mov eax, dword ptr [esp + 8]
- mov dword ptr [Int386_regsin], eax
- mov eax, dword ptr [esp + 12]
- mov dword ptr [Int386_regsout], eax
-
- /* Save all registers + segment registers */
- push ds
- push es
- push fs
- push gs
- pusha
+PUBLIC _Relocator16Boot
+_Relocator16Boot:
/* Copy input registers */
- mov esi, dword ptr [Int386_regsin]
+ mov esi, dword ptr [esp + 4]
mov edi, BSS_RegisterSet
mov ecx, REGS_SIZE / 4
rep movsd
- /* Set the function ID */
- mov bx, FNID_Int386
+ /* Set the stack segment/offset */
+ // Since BSS_CallbackReturn contains a ULONG, store in its high word
+ // the stack segment and in its low word the stack offset.
+ mov ax, word ptr [esp + 8]
+ shl eax, 16
+ mov ax, word ptr [esp + 12]
+ mov dword ptr ds:[BSS_CallbackReturn], eax
+
+ /*
+ * Set the code segment/offset (Copy entry point)
+ * NOTE: We permanently *ERASE* the contents of ds:[BSS_RealModeEntry]
+ * but it is not a problem since we are going to place the machine in
+ * a permanent new CPU state.
+ */
+ // Since BSS_RealModeEntry contains a ULONG, store in its high word
+ // the code segment and in its low word the code offset.
+ mov ax, word ptr [esp + 16]
+ shl eax, 16
+ mov ax, word ptr [esp + 20]
+ mov dword ptr ds:[BSS_RealModeEntry], eax
- /* Set continue address and switch to real mode */
- mov dword ptr [ContinueAddress], offset Int386_return
+ /* Set the function ID and switch to real mode (we don't return) */
+ mov bx, FNID_Relocator16Boot
jmp SwitchToReal
-Int386_return:
-
- /* Copy output registers */
- mov esi, BSS_RegisterSet
- mov edi, dword ptr [Int386_regsout]
- mov ecx, REGS_SIZE / 4
- rep movsd
-
- popa
- pop gs
- pop fs
- pop es
- pop ds
- ret
-
/*
* U16 PxeCallApi(U16 Segment, U16 Offset, U16 Service, VOID *Parameter);
*/
PUBLIC _PxeCallApi
_PxeCallApi:
- push ebp
- mov ebp, esp
-
- pusha
- push es
-
/* copy entry point */
- mov eax, [ebp + 8]
+ mov eax, [esp + 4]
shl eax, 16
- mov ax, [ebp + 12]
+ mov ax, [esp + 8]
mov dword ptr ds:[BSS_PxeEntryPoint], eax
/* copy function */
- mov ax, [ebp + 16]
+ mov ax, [esp + 12]
mov word ptr ds:[BSS_PxeFunction], ax
/* convert pointer to data buffer to segment/offset */
- mov eax, [ebp + 20]
+ mov eax, [esp + 16]
shr eax, 4
and eax, HEX(0f000)
mov word ptr ds:[BSS_PxeBufferSegment], ax
- mov eax, [ebp + 20]
+ mov eax, [esp + 16]
and eax, HEX(0ffff)
mov word ptr ds:[BSS_PxeBufferOffset], ax
+ pusha
+
/* Set the function ID and call realmode */
mov bx, FNID_PxeCallApi
call i386CallRealMode
- pop es
popa
- mov esp, ebp
- pop ebp
-
mov ax, word ptr [BSS_PxeResult]
ret
-PUBLIC _Reboot
-_Reboot:
- /* Set the function ID */
- mov bx, FNID_Reboot
-
- /*Switch to real mode (We don't return) */
- jmp SwitchToReal
-
-
-PUBLIC _ChainLoadBiosBootSectorCode
-_ChainLoadBiosBootSectorCode:
- /* Set the boot drive */
- mov dl, byte ptr [_FrldrBootDrive]
-
- /* Set the function ID */
- mov bx, FNID_ChainLoadBiosBootSectorCode
-
- /*Switch to real mode (We don't return) */
- jmp SwitchToReal
-
-
PUBLIC i386CallRealMode
i386CallRealMode:
/* Set continue address and switch to real mode */
- mov dword ptr [ContinueAddress], offset i386CallRealMode_return
+ mov dword ptr ds:[ContinueAddress], offset i386CallRealMode_return
jmp SwitchToReal
i386CallRealMode_return:
ret
/* Entrypoint for realmode function calls
* ContinueAddress must be set to the return point from realmode
* bx must be set to the ID of the realmode function to call. */
+PUBLIC SwitchToReal
SwitchToReal:
/* Set sane segments */
- mov ax, PMODE_DS
- mov ds, ax
- mov es, ax
- mov fs, ax
- mov gs, ax
- mov ss, ax
+ mov ax, PMODE_DS
+ mov ds, ax
+ mov es, ax
+ mov fs, ax
+ mov gs, ax
+ mov ss, ax
- /* Save 32-bit stack pointer */
- mov dword ptr [stack32], esp
+ /* Save 32-bit stack pointer */
+ mov dword ptr ds:[stack32], esp
- /* jmp to 16-bit segment to set the limit correctly */
+ /* jmp to 16-bit segment to set the limit correctly */
.byte HEX(0ea) // jmp far RMODE_CS:switch_to_real16
SwitchToReal16Address:
.long 0 // receives address of switch_to_real16
nop
- /* 16-bit stack pointer */
+ /* 16-bit stack pointer */
stack16:
- .word STACK16ADDR
+ .word STACK16ADDR
- /* 32-bit stack pointer */
+ /* 32-bit stack pointer */
stack32:
- .long STACKADDR
+ .long STACKADDR
- .align 4 /* force 4-byte alignment */
+ .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)
+ /* 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 /* Base Address */
-
-/* Real-mode IDT pointer */
-rmode_idtptr:
- .word HEX(3ff) /* Limit */
- .long 0 /* Base Address */
+ .word HEX(27) /* Limit */
+ .long gdt /* Base Address */
+// See _i386IdtDescriptor
PUBLIC i386idtptr
i386idtptr:
- .word 255 /* Limit */
- .long _i386Idt /* Base Address */
+ .word 255 /* Limit */
+ .long _i386Idt /* Base Address */
PUBLIC _FrldrBootDrive
_FrldrBootDrive:
projects / reactos.git / blobdiff