Source code of Windows XP (NT5)
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106 lines
3.4 KiB

title "Thread Startup"
;++
;
; Copyright (c) 2000 Microsoft Corporation
;
; Module Name:
;
; threadbg.asm
;
; Abstract:
;
; This module implements the code necessary to startup a thread in kernel
; mode.
;
; Author:
;
; David N. Cutler (davec) 10-Jun-2000
;
; Environment:
;
; Kernel mode only, IRQL APC_LEVEL.
;
;--
include ksamd64.inc
altentry KiThreadStartup
extern KeBugCheck:proc
extern KiExceptionExit:proc
subttl "Thread Startup"
;++
;
; Routine Description:
;
; This routine is called at thread startup. Its function is to call the
; initial thread procedure. If control returns from the initial thread
; procedure and a user mode context was established when the thread
; was initialized, then the user mode context is restored and control
; is transfered to user mode. Otherwise a bug check will occur.
;
; N.B. At thread startup the stack contains at least a legacy floating
; point save area and an exception frame. If the thread is a user
; mode thread, then it also contains a trap frame. The exception
; frame contains the system start call address and parameters. As
; soon as these values are captured the exception frame is deallocated.
;
; Arguments:
;
; r12 - Supplies a logical value that specifies whether a user mode thread
; context was established when the thread was initialized.
;
; r13 - Supplies the starting context parameter for the initial thread
; routine.
;
; r14 - Supplies the starting address of the initial thread routine.
;
; r15 - Supplies the starting address of the initial system routine.
;
; rbp - Supplies the address of a trap frame if a user thread is being
; started. Otherwise, it contains the value 128 and is not meaningful.
;
; Return Value:
;
; None.
;
;--
NESTED_ENTRY KxThreadStartup, _TEXT$00
alloc_stack LEGACY_SAVE_AREA_LENGTH - 8 ; allocate legacy save area
set_frame rbx, 0 ; set frame register
END_PROLOGUE
sub rsp, KEXCEPTION_FRAME_LENGTH ; allocate exception frame
ALTERNATE_ENTRY KiThreadStartup
mov rbx, ExRbx[rsp] ; set frame register
mov r12, ExR12[rsp] ; get user context address
mov r13, ExR13[rsp] ; get startup context parameter
mov r14, ExR14[rsp] ; get initial thread routine address
mov r15, ExR15[rsp] ; get initial system routine address
test r12, r12 ; test if user context specified
jnz short KiTs10 ; if nz, user context specified
add rsp, KEXCEPTION_FRAME_LENGTH - (2 * 8) ; deallocate exception frame
KiTs10: mov ecx, APC_LEVEL ; set IRQL to APC level
SetIrql ;
mov rcx, r14 ; set address of thread routine
mov rdx, r13 ; set startup context parameter
call r15 ; call system routine
test r12, r12 ; test if user context specified
jz short KiTs20 ; if z, no user context specified
jmp KiExceptionExit ; finish in exception exit code
KiTs20: mov rcx, NO_USER_MODE_CONTEXT ; set bug check parameter
call KeBugCheck ; call bug check - no return
NESTED_END KxThreadStartup, _TEXT$00
end