8085: add hooks for magic Z80 M1 emulation

diff --git a/Kernel/lowlevel-8085.s b/Kernel/lowlevel-8085.s
index 7e920ad..4f72cd7 100644 (file)
--- a/Kernel/lowlevel-8085.s
+++ b/Kernel/lowlevel-8085.s
@@ -297,6 +297,10 @@ interrupt_handler:
 intout:
        xra a
        sta U_DATA__U_ININTERRUPT
+
+       FAKE_IRET               ! Usually null but some platforms
+                               ! have hacks for Z80 peripherals
+
        lda U_DATA__U_INSYS
        ora a
        jnz interrupt_pop
@@ -342,6 +346,12 @@ preemption:
        lhld istack_switched_sp
        shld U_DATA__U_SYSCALL_SP
        lxi sp,kstack_top
+
+       !
+       !       So any Z80 style devices see an 'iret'
+       !
+       FAKE_IRET
+
        !
        !       Mark ourselves as in a system call
        !

diff --git a/Kernel/platform-v85/kernel.def b/Kernel/platform-v85/kernel.def
index 91b882e..e3f55f0 100644 (file)
--- a/Kernel/platform-v85/kernel.def
+++ b/Kernel/platform-v85/kernel.def
@@ -17,3 +17,6 @@ CONFIG_SWAP               = 1
 #define DI             mvi a,0x0a ; sim
 
 #define EI             mvi a,0x08 ; sim
+
+/* We have no Z80 peripherals and no iret fakery */
+#define FAKE_IRET