z80-banked: sync up with work so far

diff --git a/Kernel/lowlevel-z80-banked.s b/Kernel/lowlevel-z80-banked.s
index 0a52c8e..b4e241b 100644 (file)
--- a/Kernel/lowlevel-z80-banked.s
+++ b/Kernel/lowlevel-z80-banked.s
@@ -25,7 +25,9 @@
        ; platform provided functions
        .globl map_kernel
        .globl map_process_always
-        .globl map_save
+       .globl map_kernel_di
+       .globl map_process_always_di
+        .globl map_save_kernel
         .globl map_restore
        .globl outchar
        .globl _need_resched
@@ -49,6 +51,7 @@
 
         ; imported symbols
        .globl _chksigs
+       .globl _int_disabled
         .globl _platform_monitor
         .globl _unix_syscall
         .globl outstring
@@ -98,6 +101,9 @@ deliver_signals_2:
        ; Indicate processed
        xor a
        ld (U_DATA__U_CURSIG), a
+       ; and we will handle the signal with interrupts on so clear the
+       ; flag
+       ld (_int_disabled),a
 
        ; Semantics for now: signal delivery clears handler
        ld (hl), a
@@ -125,7 +131,9 @@ signal_return:
        ;
        ld (U_DATA__U_SYSCALL_SP), sp
        ld sp, #kstack_top
-       call map_kernel
+       ld a,#1
+       ld (_int_disabled),a
+       call map_kernel_di
        push af
        call _chksigs
        pop af
@@ -391,13 +399,7 @@ interrupt_handler:
        ld a, (0)
 .endif
 
-       call map_save
-       ;
-       ;       FIXME: re-implement sanity checks and add a stack one
-       ;
-
-       ; We need the kernel mapped for the IRQ handling
-       call map_kernel
+       call map_save_kernel
 
 .ifeq PROGBASE
        cp #0xC3
@@ -409,6 +411,9 @@ interrupt_handler:
        ld (_inint), a
        ; So we know that this task should resume with IRQs off
        ld (U_DATA__U_ININTERRUPT), a
+       ; Load the interrupt flag properly. It got an implicit di from
+       ; the IRQ being taken
+       ld (_int_disabled),a
 
        push af
        call _platform_interrupt
@@ -452,6 +457,8 @@ intret:
 
        ; Then unstack and go.
 interrupt_pop:
+       xor a
+       ld (_int_disabled),a
         pop iy
         pop ix
         pop hl
@@ -674,19 +681,41 @@ _in:
        in l, (c)
        ret
 
+;
+;      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-banked.s"
-.else
-       .include "lowlevel-z80-cmos-banked.s"
-.endif
+___hard_irqrestore:
+       pop bc
+       pop de
+       pop hl
+       push hl
+       push de
+       push bc
+       di
+       ld a,l
+       ld (_int_disabled),a
+       or a
+       ret nz
+       ei
+       ret
 
        .area _COMMONMEM