X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Fx86%2Fproc.asm;h=732d35fce2b3234a757f67287a27b5f336982d15;hb=18b264927674c480481466c40368554fb72f560f;hp=41623bdd23fc63cacdee6f491cf3f0cc7145df1d;hpb=83612bb37fbd8e84d90ecb9e6a7157aadd1e2175;p=tpg%2Facess2.git

diff --git a/Kernel/arch/x86/proc.asm b/Kernel/arch/x86/proc.asm
index 41623bdd..732d35fc 100644
--- a/Kernel/arch/x86/proc.asm
+++ b/Kernel/arch/x86/proc.asm
@@ -74,6 +74,9 @@ SchedulerBase:
 	push fs
 	push gs
 	
+	mov eax, dr0
+	push eax	; Debug Register 0, Current Thread
+	
 	mov ax, 0x10
 	mov ds, ax
 	mov es, ax
@@ -97,17 +100,19 @@ SchedulerBase:
 	jnz .sendEOI
 	%endif
 	
-	mov dx, 0x20
 	mov al, 0x20
-	out dx, al		; ACK IRQ
+	out 0x20, al		; ACK IRQ
 	%if USE_MP
 	jmp .ret
 	
 .sendEOI:
 	mov eax, DWORD [gpMP_LocalAPIC]
-	mov DWORD [eax+0x0B0], 1
+	mov DWORD [eax+0x0B0], 0
 	%endif
 .ret:
+	pop eax	; Debug Register 0, Current Thread
+	mov dr0, eax
+
 	pop gs
 	pop fs
 	pop es
@@ -145,19 +150,22 @@ SpawnTask:
 .parent:
 	ret
 
-;
+; void Proc_ReturnToUser(void *Method, Uint Parameter)
 ; Calls a user fault handler
 ;
 [global Proc_ReturnToUser]
 [extern Proc_GetCurThread]
 Proc_ReturnToUser:
-	; EBP is the handler to use
+	push ebp
+	mov ebp, esp
+	; [EBP+4]: handler to use
+	; [EBP+8]: parameter
 	
 	call Proc_GetCurThread
 	
 	; EAX is the current thread
 	mov ebx, eax
-	mov eax, [ebx+40]	; Get Kernel Stack
+	mov eax, [ebx+12*4]	; Get Kernel Stack
 	sub eax, KSTACK_USERSTATE_SIZE
 	
 	;
@@ -199,10 +207,10 @@ Proc_ReturnToUser:
 	jnz .justKillIt
 	
 	; Get and alter User SP
-	mov ecx, edx
-	mov edx, [ebx+60]	; Get Signal Number from TCB
-	mov [ecx+4], edx	; Parameter (Signal/Error Number)
-	mov [ecx], DWORD User_Syscall_RetAndExit	; Return Address
+	mov edi, edx
+	mov edx, [ebp+8]	; Get parameter
+	mov [edi+4], edx	; save to user stack
+	mov [edi], DWORD User_Syscall_RetAndExit	; Return Address
 	
 	; Restore Segment Registers
 	mov ax, 0x23
@@ -212,10 +220,11 @@ Proc_ReturnToUser:
 	mov gs, ax
 	
 	push 0x23	; SS
-	push ecx	; ESP
+	push edi	; ESP
 	push 0x202	; EFLAGS (IP and Rsvd)
 	push 0x1B	; CS
-	push ebp	; EIP
+	mov eax, [ebp+4]	; Method to call
+	push eax	; EIP
 	
 	iret
 	
@@ -228,7 +237,7 @@ Proc_ReturnToUser:
 	int 0xAC
 
 [global GetCPUNum]
-GetCPUNum:
+GetCPUNum:	; TODO: Store in debug registers
 	xor eax, eax
 	str ax
 	sub ax, 0x30
@@ -237,6 +246,13 @@ GetCPUNum:
 
 ; Usermode code exported by the kernel
 [section .usertext]
+; Export a place for the user to jump to to call a syscall
+; - Allows the kernel to change the method easily
+User_Syscall:
+	xchg bx, bx	; MAGIC BREAKPOINT
+	int 0xAC
+
+; A place to return to and exit
 User_Syscall_RetAndExit:
 	push eax
 	call User_Syscall_Exit