X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;ds=sidebyside;f=Kernel%2Farch%2Fx86%2Fdesctab.asm;h=dc064f579f7287910e44e1d6f66f00b7021892e7;hb=7e5607004c3221d55c7992148b2f0d958cf28533;hp=4223e6f18f199a2d9dadd3b9e3669defb9fd349f;hpb=3998cfbbadb005bf3ad52ea2538dc21f82864ddc;p=tpg%2Facess2.git

diff --git a/Kernel/arch/x86/desctab.asm b/Kernel/arch/x86/desctab.asm
index 4223e6f1..dc064f57 100644
--- a/Kernel/arch/x86/desctab.asm
+++ b/Kernel/arch/x86/desctab.asm
@@ -54,6 +54,8 @@ Desctab_Install:
 .pl0code:
 
 	; 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
@@ -64,23 +66,28 @@ Desctab_Install:
 	or ax, 0x8000
 	mov	WORD [gIDT + %1*8 + 4], ax
 %endmacro
+	; 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
 	SET_USER	0xAC
 	SET_TRAP	0xAC	; Interruptable
 	
+	; MP ISRs
 	%if USE_MP
 	SETISR	0xEE	; 0xEE Timer
 	SETISR	0xEF	; 0xEF Spurious Interrupt
@@ -203,7 +210,7 @@ DEF_SYSCALL	0xAC	; Acess System Call
 [extern SchedulerBase]
 ; AP's Timer Interrupt
 Isr0xEE:
-	push 0
+	push 0	; Line up with interrupt number
 	xchg bx, bx	; MAGIC BREAK
 	jmp SchedulerBase
 ; Spurious Interrupt
@@ -220,7 +227,8 @@ Isr0xEF:
 [extern SchedulerBase]
 [extern SetAPICTimerCount]
 Isr240:
-	push 0
+	push 0	; Line up with Argument in errors
+	push 0	; CPU Number
 	;xchg bx, bx	; MAGIC BREAK
 Isr240.jmp:
 	%if USE_MP
@@ -280,6 +288,18 @@ SyscallCommon:
 	call SyscallHandler
 	add esp, 4
 	
+	; Pass changes to TF on to the user
+	; EFLAGS is stored at ESP[4+8+2+2]
+	; 4 Segment Registers
+	; 8 GPRs
+	; 2 Error Code / Interrupt ID
+	; 2 CS/EIP
+	pushf
+	pop eax
+	and eax, 0x100	; 0x100 = Trace Flag
+	and WORD [esp+(4+8+2+2)*4], ~0x100	; Clear
+	or DWORD [esp+(4+8+2+2)*4], eax	; Set for user
+	
 	pop gs
 	pop fs
 	pop es
@@ -293,6 +313,8 @@ SyscallCommon:
 ; ------------
 [extern IRQ_Handler]
 [global IRQCommon]
+[global IRQCommon_handled]
+IRQCommon_handled equ IRQCommon.handled
 IRQCommon:
 	pusha
 	push ds
@@ -308,6 +330,7 @@ IRQCommon:
 	
 	push esp
 	call IRQ_Handler
+.handled:
 	add esp, 4
 	
 	pop gs