z80-thunked: first cut at new irq handling

diff --git a/Kernel/lowlevel-z80-thunked.s b/Kernel/lowlevel-z80-thunked.s
index aeb0e13..a942aca 100644 (file)
--- a/Kernel/lowlevel-z80-thunked.s
+++ b/Kernel/lowlevel-z80-thunked.s
@@ -50,6 +50,7 @@
 
         ; imported symbols
        .globl _chksigs
+       .globl _int_disabled
         .globl _platform_monitor
         .globl _unix_syscall
         .globl outstring
@@ -213,6 +214,7 @@ interrupt_handler:
        ld a,#1
        ld (_inint),a
        ld (U_DATA__U_ININTERRUPT),a
+       ld (_int_disabled),a
        call _platform_interrupt
        xor a
        ld (_inint),a
@@ -239,6 +241,7 @@ intsig:
        ; Nothing special to do
 no_sig:
        xor a
+       ld (_int_disabled),a
        ld e,a
        ld a,(U_DATA__U_PAGE+1)
 intret:
@@ -258,6 +261,7 @@ intret:
 interrupt_kernel:
        call map_restore_low
        xor a
+       ld (_int_disabled),a
        ld e,a
        jr intret
 ;
@@ -267,6 +271,7 @@ interrupt_kernel:
 interrupt_sig:
        ld e,a
        xor a
+       ld (_int_disabled),a
        ld d,a
        ld (U_DATA__U_CURSIG),a
        ld hl,#U_DATA__U_SIGVEC
@@ -425,18 +430,35 @@ _in:
        ret
 
 ;
-;      Enable interrupts
+;      Deal with all the NMOS Z80 bugs and the buggy emulators by
+;      simply tracing our own interrupt status. It's cheaper this way
+;      but does mean any code that is using di and friends directly needs
+;      to be a lot more careful. We can also make irqflags_t 8bit and
+;      fastcall the irqrestore later on FIXME
 ;
 ___hard_ei:
+       xor a
+       ld (_int_disabled),a
        ei
        ret
 
-;
-;      Pull in the CPU specific workarounds
-;
+___hard_di:
+       ld hl,#_int_disabled
+       di
+       ld a,(hl)
+       ld (hl),#1
+       ld l,a
+       ret
 
-.ifeq CPU_NMOS_Z80
-       .include "lowlevel-z80-nmos.s"
-.else
-       .include "lowlevel-z80-cmos.s"
-.endif
+___hard_irqrestore:
+       pop de
+       pop hl
+       push hl
+       push de
+       di
+       ld a,l
+       ld (_int_disabled),a
+       or a
+       ret nz
+       ei
+       ret