216 lines
5.8 KiB
NASM
216 lines
5.8 KiB
NASM
title "Processor type and stepping detection"
|
||
;++
|
||
;
|
||
; Copyright (c) 1989 Microsoft Corporation
|
||
;
|
||
; Module Name:
|
||
;
|
||
; main.asm
|
||
;
|
||
; Abstract:
|
||
;
|
||
; This file implements the main entry code for x86 hardware detection
|
||
; module. This assembly file is required in order to link C modules
|
||
; into a "/TINY" (single segment) memory module.
|
||
;
|
||
; Author:
|
||
;
|
||
; Shie-Lin Tzong (shielint) 15-Feb-1992.
|
||
; The code is extracted from NTLDR su.asm.
|
||
;
|
||
; Environment:
|
||
;
|
||
; x86 Real Mode.
|
||
;
|
||
; Revision History:
|
||
;
|
||
;
|
||
; Build Notes:
|
||
; ~~~~~~~~~~~~
|
||
; The microsoft C compiler will not produce "tiny" model programs. In the
|
||
; tiny model, the entire program consists of only one segment. The small
|
||
; model produced by our compilers consists of two segments: DGROUP and _TEXT.
|
||
; If you convert a small model program into a tiny model program, DS (which
|
||
; should point to DGROUP (bss,const,data) will always be wrong. For this reason
|
||
; we need an assembly module to do a simple run-time fixup on SS and DS. To
|
||
; guarantee that DS will point to DGROUP no matter where the detection module
|
||
; is loaded, the paragraph (shifted right four bits) offset of DGROUP from
|
||
; _TEXT must be added to the value in CS to compute DS and SS.
|
||
;
|
||
; We get the linker to fixup the offset of the beginning of the dgroup segment
|
||
; relative to the beginning of the code segment and it's this value added
|
||
; to the value in CS that allows us to build a "tiny" model program in C
|
||
; without a lot of munging around in order to get the data reference offsets
|
||
; in the code correct.
|
||
;
|
||
; If the _TEXT:DGROUP fixup appears in other files (which it does), the linker
|
||
; will not compute the correct value unless the accumulated data pointer is
|
||
; zero when it gets there. Therefore, no data should be placed in the data segment
|
||
; until after all instances of _TEXT:DGROUP have been encountered by the linker.
|
||
; The linker processes files from right to left on the command line.
|
||
;
|
||
;--
|
||
|
||
.386p
|
||
|
||
include main.inc
|
||
|
||
_DATA SEGMENT PARA USE16 PUBLIC 'DATA'
|
||
|
||
;
|
||
; Define double wrod to save caller's (ntldr's) stack pointer
|
||
;
|
||
|
||
NtldrStack df 0 ; saved area for ss:esp
|
||
|
||
dw 2048 dup (0)
|
||
DetectionStack equ $
|
||
|
||
_DATA ends
|
||
|
||
_TEXT segment para use16 public 'CODE'
|
||
ASSUME CS: _TEXT, DS: DGROUP, SS: DGROUP
|
||
|
||
|
||
;++
|
||
;
|
||
; VOID
|
||
; DetectionMain (
|
||
; ULONG HeapStart,
|
||
; ULONG HeapSize,
|
||
; ULONG ConfigurationTree,
|
||
; ULONG HeapUsed,
|
||
; ULONG LoadOptions,
|
||
; ULONG LoadOptionsLength
|
||
; )
|
||
;
|
||
; Routine Description:
|
||
;
|
||
; This is the entry point of the detection module.
|
||
; Memory from HeapStart to (HeapStart + HeapSize) is allocated for detection
|
||
; module to store the hardware configuration tree.
|
||
; Note that detection module loaded address will be resued by loader after
|
||
; the control is passed back to ntldr.
|
||
;
|
||
; Arguments:
|
||
;
|
||
; HeapStart - supplies a 32 bit FLAT starting addr of the heap
|
||
;
|
||
; HeapSize - Supplies the size of the useable heap
|
||
;
|
||
; ConfigurationTree - Supplies a 32 bit FLAT address of the variable to
|
||
; receive the configuration tree.
|
||
;
|
||
; HeapUsed - Supplies a 32 bit FLAT address of the variable to receive
|
||
; the size of heap we acually used.
|
||
;
|
||
; LoadOptions - Supplies a 32 bit FLAT address of the load options string.
|
||
;
|
||
; LoadOptionsLength - Supplies the length of the LoadOptions string. Note,
|
||
; this is for sanity check to make sure the LoadOptions string is valid.
|
||
; (in case use usews Nt 1.0 ntldr with the new ntdetect.com.)
|
||
;
|
||
; Return Value:
|
||
;
|
||
; None.
|
||
;
|
||
;--
|
||
;
|
||
|
||
;
|
||
; Run-time fixups for stack and data segment
|
||
;
|
||
|
||
public DetectionMain
|
||
DetectionMain:
|
||
|
||
;
|
||
; Save all the registers we need to preserved on NTLDR's stack
|
||
;
|
||
|
||
push ebp
|
||
mov ebp, esp
|
||
and ebp, 0ffffh
|
||
push ds
|
||
push es
|
||
push ebx
|
||
push esi
|
||
push edi
|
||
|
||
;
|
||
; Compute the paragraph needed for DS
|
||
;
|
||
|
||
mov cx,offset _TEXT:DGROUP ; first calculate offset to data
|
||
shr cx,4 ; must be para aligned
|
||
|
||
mov ax,cs ; get base of code
|
||
add ax,cx ; add paragraph offset to data
|
||
|
||
;
|
||
; Make DS point to the paragraph address of DGROUP
|
||
;
|
||
|
||
mov ds,ax ; ds now points to beginning of DGROUP
|
||
mov es,ax
|
||
|
||
;
|
||
; Save old stack pointer and set up our own stack.
|
||
;
|
||
|
||
mov ecx, esp
|
||
mov dword ptr NtldrStack, ecx
|
||
mov cx, ss
|
||
mov word ptr NtldrStack + 4, cx
|
||
|
||
mov ebx, [bp + 8] ; [ebx] = Heap Start
|
||
mov ecx, [bp + 12] ; [ecx] = Heap Size
|
||
mov esi, [bp + 16] ; [esi] -> addr of ConfigurationTree
|
||
mov edi, [bp + 20] ; [edi] -> Addr of HeapUsed variable
|
||
mov edx, [bp + 24] ; [edx]-> Addr of LoadOptions string
|
||
mov ebp, [bp + 28] ; [ebp] = length of LoadOptions
|
||
|
||
mov ss,ax
|
||
mov esp,offset DGROUP:DetectionStack ; (ss:esp) = top of internal stack
|
||
|
||
;
|
||
; Set up parameters and invoke real detection code to collect hardware
|
||
; information.
|
||
;
|
||
|
||
push ebp
|
||
push edx
|
||
push edi
|
||
push esi
|
||
push ecx
|
||
push ebx
|
||
|
||
xor eax, eax
|
||
xor ebx, ebx
|
||
xor ecx, ecx
|
||
xor edx, edx
|
||
xor esi, esi
|
||
xor edi, edi
|
||
|
||
call _HardwareDetection
|
||
|
||
;
|
||
; The hardware detection is done. We need to switch to ntldr's stack,
|
||
; restore registers and return back to ntldr.
|
||
;
|
||
|
||
lss esp, NtldrStack
|
||
|
||
pop edi ; retore registers
|
||
pop esi
|
||
pop ebx
|
||
pop es
|
||
pop ds
|
||
pop ebp
|
||
|
||
retf
|
||
|
||
_TEXT ends
|
||
|
||
end DetectionMain
|