X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Fx86%2Fdesctab.asm;h=f6cc14e1b7e3bfcf26f9a9ff5e7b068e116b0139;hb=01fbfb424865291e00242681662ed9b20c33a524;hp=b80c355cee26813935803c5bf7a94e918ebf41bf;hpb=83612bb37fbd8e84d90ecb9e6a7157aadd1e2175;p=tpg%2Facess2.git

diff --git a/Kernel/arch/x86/desctab.asm b/Kernel/arch/x86/desctab.asm
index b80c355c..f6cc14e1 100644
--- a/Kernel/arch/x86/desctab.asm
+++ b/Kernel/arch/x86/desctab.asm
@@ -31,7 +31,8 @@ gGDTPtr:
 ALIGN 8
 [global gIDT]
 gIDT:
-	times	256	dd	0x00080000,0x00000F00
+	; CS = 0x08, Type = 32-bit Interrupt (0xE = 1 110)
+	times	256	dd	0x00080000,0x00000E00
 [global gIDTPtr]
 gIDTPtr:
 	dw	256 * 16 - 1	; Limit
@@ -52,7 +53,9 @@ Desctab_Install:
 	jmp 0x08:.pl0code
 .pl0code:
 
-	; Set IDT
+	; Set up IDT
+	; Helper Macros
+	; - Set an IDT entry to an ISR
 %macro SETISR	1
 	mov eax, Isr%1
 	mov	WORD [gIDT + %1*8], ax
@@ -63,25 +66,34 @@ Desctab_Install:
 	or ax, 0x8000
 	mov	WORD [gIDT + %1*8 + 4], ax
 %endmacro
-%macro SETUSER	1
-	mov	ax, WORD [gIDT + %1*8 + 4]
-	or ax, 0x6000
-	mov	WORD [gIDT + %1*8 + 4], ax
+	; Enable user calling of an ISR
+%macro SET_USER	1
+	or WORD [gIDT + %1*8 + 4], 0x6000
+%endmacro
+	; Set an ISR as a trap (leaves interrupts enabled when invoked)
+%macro SET_TRAP	1
+	or WORD [gIDT + %1*8 + 4], 0x0100
 %endmacro
+
+	; Error handlers
 	%assign	i	0
 	%rep 32
 	SETISR	i
 	%assign i i+1
 	%endrep
 	
+	; User Syscall
 	SETISR	0xAC
-	SETUSER	0xAC
+	SET_USER	0xAC
+	SET_TRAP	0xAC	; Interruptable
 	
+	; MP ISRs
 	%if USE_MP
 	SETISR	0xEE	; 0xEE Timer
 	SETISR	0xEF	; 0xEF Spurious Interrupt
 	%endif
-	
+
+	; IRQs
 	%assign	i	0xF0
 	%rep 16
 	SETISR	i
@@ -129,14 +141,14 @@ Desctab_Install:
 %macro	ISR_ERRNO	1
 [global Isr%1]
 Isr%1:
-	xchg bx, bx
+	;xchg bx, bx
 	push	%1
 	jmp	ErrorCommon
 %endmacro
 %macro	ISR_NOERR	1
 [global Isr%1]
 Isr%1:
-	xchg bx, bx
+	;xchg bx, bx
 	push	0
 	push	%1
 	jmp	ErrorCommon