Fixed Proc_ReturnToUser's dependence on the structure of tThread

[tpg/acess2.git] / Kernel / arch / x86 / proc.asm

diff --git a/Kernel/arch/x86/proc.asm b/Kernel/arch/x86/proc.asm
index 80cc3cb..e0598a5 100644 (file)
--- a/Kernel/arch/x86/proc.asm
+++ b/Kernel/arch/x86/proc.asm
@@ -150,13 +150,16 @@ 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
        
@@ -204,10 +207,10 @@ Proc_ReturnToUser:
        jnz .justKillIt
        
        ; Get and alter User SP
-       mov ecx, edx
-       mov edx, [ebx+68]       ; Get Signal Number from TCB (TODO: Get this from parameters)
-       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
@@ -217,10 +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
        
@@ -233,7 +237,7 @@ Proc_ReturnToUser:
        int 0xAC
 
 [global GetCPUNum]
-GetCPUNum:
+GetCPUNum:     ; TODO: Store in debug registers
        xor eax, eax
        str ax
        sub ax, 0x30
@@ -245,7 +249,7 @@ GetCPUNum:
 ; 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
+       xchg bx, bx     ; MAGIC BREAKPOINT
        int 0xAC
 
 ; A place to return to and exit