more sane directory name, updated binaries

src/kernal/interrupts/ea31.default_irq_handler.s

@@ -0,0 +1,56 @@
+// #LAYOUT# STD *        #TAKE
+// #LAYOUT# *   KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+
+default_irq_handler:
+
+#if CONFIG_RS232_UP9600
+
+	jsr rs232_count_channels
+	cpx #$00
+	beq !+
+	jsr up9600_irq
+!:
+
+#endif // CONFIG_RS232_UP9600
+
+
+	jsr cursor_blink
+	jsr JSCNKEY
+	jsr JUDTIM // update jiffy clock
+
+
+#if CONFIG_TAPE_NORMAL || CONFIG_TAPE_TURBO
+
+	// Turn tape motor on/off depending on the button state
+	// For CAS1 (tape motor interlock) variable description, see Mapping the C64, page 7
+
+	lda CPU_R6510
+	and #$10
+	beq !+                             // branch if tape button pressed
+
+	jsr tape_motor_off
+	lda #$00
+	sta CAS1
+	beq default_irq_handler_end_tape   // branch always
+!:
+	lda CAS1
+	bne default_irq_handler_end_tape
+	jsr tape_motor_on
+
+default_irq_handler_end_tape:
+
+#endif // CONFIG_TAPE_NORMAL || CONFIG_TAPE_TURBO
+
+
+#if CONFIG_PLATFORM_COMMODORE_64
+
+	// Acknowledge CIA interrupt and return
+	jmp clear_cia1_interrupt_flag_and_return_from_interrupt
+
+#else
+
+	jmp return_from_interrupt
+
+#endif

src/kernal/interrupts/ea31.interop

@@ -0,0 +1,8 @@
+All the Kernal routines, for which there are vectors in $0314-$0333, have to be available at their original addresses.
+
+Reason: some autostart software (https://codebase64.org/doku.php?id=base:autostarting_disk_files) override these vectors, so that some point
+to new locations (custom IRQ routine, custom STOP routine, etc.), while others points the original Kernal routines. Different techniques modify
+different vectors (while resetting others to original C64 locations), some don't change the vectors at all, but might still put the original
+C64 Kernal addresses there (for example, if the file overrides keyboard input buffer and screeen memory).
+
+For various cartridges (like IDE64) this just means disabling their extensions; for us that would mean improperly functionning Kernal.

src/kernal/interrupts/ea7e.ack_cia1_return_from_interrupt.s

@@ -0,0 +1,17 @@
+// #LAYOUT# STD *        #TAKE
+// #LAYOUT# X16 *        #IGNORE
+// #LAYOUT# *   KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+
+// https://csdb.dk/forums/index.php?roomid=11&topicid=5776
+// Clear the CIA1 interrupt flag, and then fall through to
+// the return from interrupt routine
+
+clear_cia1_interrupt_flag_and_return_from_interrupt:
+
+	// We have free choice of LDA, LDX or LDY to achieve this goal
+	// in 3 bytes and minimum cycles. Thus we randomly choose LDY.
+	ldy CIA1_ICR
+
+	// FALL THROUGH to $EA81

src/kernal/interrupts/ea81.return_from_interrupt.s

@@ -0,0 +1,27 @@
+// #LAYOUT# STD *        #TAKE
+// #LAYOUT# *   KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+// The IRQ is a commonly messed with thing on the C64,
+// so we need to handle entry points that are commonly
+// relied upon, including:
+// $EA31 - Standard IRQ routine
+// $EA61 - Check keyboard, but do not update timer? https://github.com/cc65/cc65/issues/324
+// $EA81 - https://www.lemon64.com/forum/viewtopic.php?t=2112&sid=6ea01982b26da69783120a7923ca46fb
+// Also the $0314 vector is widely used (e.g., https://www.lemon64.com/forum/viewtopic.php?t=2112&sid=6ea01982b26da69783120a7923ca46fb)
+
+
+return_from_interrupt:
+
+	// Restore registers and return
+	// Sequence according to Computes Mapping the 64 p73
+
+	ply_trash_a
+	plx_trash_a
+	pla
+
+	// FALLTROUGH
+
+return_from_interrupt_rti:
+
+	rti

src/kernal/interrupts/fe47.default_nmi_handler.s

@@ -0,0 +1,41 @@
+// #LAYOUT# STD *        #TAKE
+// #LAYOUT# *   KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+
+default_nmi_handler:
+
+	// Implemented according to Computes Mapping the Commodore 64, page 74
+	// and to https://www.c64-wiki.com/wiki/Interrupt
+
+	// Save registers, sequence according to Computes Mapping the Commodore 64, page 73
+	pha
+	phx_trash_a
+	phy_trash_a
+
+	// XXX: RS-232 support is not implemented
+
+	// XXX confirm NMIs from CIA, or no other NMI will arrive!
+
+#if CONFIG_PLATFORM_COMMODORE_64
+
+	jsr cartridge_check
+	bne !+
+	jmp (ICART_WARM_START)
+!:
+
+#endif
+
+	// According to C64 Wiki, if STOP key is pressed, the routine assumes warm start request
+
+	// XXX is it right? how to check that IRQ was caused by RESTORE?
+
+	jsr JSTOP
+	bcs !+
+	jmp return_from_interrupt // no STOP pressed
+!:
+	// STOP + RESTORE - clean the address of the BRK instruction (it is not BRK) first
+	lda #$00
+	sta CMP0+0
+	sta CMP0+1
+	jmp (CBINV)

src/kernal/interrupts/fe47.interop

@@ -0,0 +1,8 @@
+All the Kernal routines, for which there are vectors in $0314-$0333, have to be available at their original addresses.
+
+Reason: some autostart software (https://codebase64.org/doku.php?id=base:autostarting_disk_files) override these vectors, so that some point
+to new locations (custom IRQ routine, custom STOP routine, etc.), while others points the original Kernal routines. Different techniques modify
+different vectors (while resetting others to original C64 locations), some don't change the vectors at all, but might still put the original
+C64 Kernal addresses there (for example, if the file overrides keyboard input buffer and screeen memory).
+
+For various cartridges (like IDE64) this just means disabling their extensions; for us that would mean improperly functionning Kernal.

src/kernal/interrupts/fe66.default_brk_handler.s

@@ -0,0 +1,38 @@
+// #LAYOUT# STD *        #TAKE
+// #LAYOUT# *   KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+
+default_brk_handler:
+
+	// Implemented according to Computes Mapping the Commodore 64, pages 73-74
+
+	sei // disable IRQs, to be sure they wont interfere
+
+#if CONFIG_PLATFORM_COMMODORE_64
+
+	ldx #$00
+	sta VIC_SCROLX           // turn the display off - we want as little screen artifacts as possible
+
+#endif
+
+	cld                      // make sure this dangerous flag is disabled
+
+#if HAS_OPCODES_65CE02
+
+	see                      // disable extended stack
+
+#endif
+
+	jsr JRESTOR
+	jsr JIOINIT
+
+	// Original routine calls just a part of CINT - but I am not sure which one. Most likely it
+	// skips the PAL/NTSC check by calling $E518. I suspect bug in the original ROM, lets
+	// call the whole CINT, just to be sure everything is initialized.
+
+	jsr CINT
+
+	cli
+
+	jmp (IBASIC_WARM_START)

src/kernal/interrupts/fe66.interop

@@ -0,0 +1,8 @@
+All the Kernal routines, for which there are vectors in $0314-$0333, have to be available at their original addresses.
+
+Reason: some autostart software (https://codebase64.org/doku.php?id=base:autostarting_disk_files) override these vectors, so that some point
+to new locations (custom IRQ routine, custom STOP routine, etc.), while others points the original Kernal routines. Different techniques modify
+different vectors (while resetting others to original C64 locations), some don't change the vectors at all, but might still put the original
+C64 Kernal addresses there (for example, if the file overrides keyboard input buffer and screeen memory).
+
+For various cartridges (like IDE64) this just means disabling their extensions; for us that would mean improperly functionning Kernal.

src/kernal/interrupts/fffa.interop

@@ -0,0 +1,2 @@
+# Find a programm that requires working NMIs / RESTORE key use
+

src/kernal/interrupts/fffa.vector_nmi.s

@@ -0,0 +1,9 @@
+// #LAYOUT# STD *        #TAKE
+// #LAYOUT# *   KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+
+// $FFFA - CPU NMI Hanlder
+// Uncontrovertial as this is also a CPU requirement.
+
+	.word hw_entry_nmi

src/kernal/interrupts/fffe.interop

@@ -0,0 +1,2 @@
+# No program will work without a working CPU IRQ vector
+*

src/kernal/interrupts/fffe.vector_irq.s

@@ -0,0 +1,10 @@
+// #LAYOUT# STD *        #TAKE
+// #LAYOUT# *   KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+
+// $FFFE - CPU IRQ Vector.
+// This is non-controvertial, as it is a 6502 CPU requirement, and we just have to point
+// it to whatever IRQ routine we make.
+
+	.word hw_entry_irq

src/kernal/interrupts/hw_entry_irq.s

@@ -0,0 +1,52 @@
+// #LAYOUT# STD *        #TAKE
+// #LAYOUT# *   KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+
+hw_entry_irq:
+
+	// The IRQ is a commonly messed with thing on the C64,
+	// so we need to handle entry points that are commonly
+	// relied upon, including:
+	// $EA31 - Standard IRQ routine
+	// $EA61 - Check keyboard, but do not update timer? https://github.com/cc65/cc65/issues/324
+	// $EA81 - https://www.lemon64.com/forum/viewtopic.php?t=2112&sid=6ea01982b26da69783120a7923ca46fb
+	// Also the $0314 vector is widely used (e.g., https://www.lemon64.com/forum/viewtopic.php?t=2112&sid=6ea01982b26da69783120a7923ca46fb)
+
+	// Save registers, sequence according to Computes Mapping the Commodore 64, page 73
+	pha
+	phx_trash_a
+	phy_trash_a
+
+#if CONFIG_CPU_MOS_6502 && CONFIG_BCD_SAFE_INTERRUPTS
+	cld // clear decimal flag to allow using it without disabling interrupts
+#endif
+
+	// Check if caused by BRK
+	tsx
+	lda $0104, x // get the pre-interrupt processor state
+	and #$10
+	bne irq_handler_brk
+
+	// Not caused by BRK - call interrupt routine (only if initialised)
+	lda CINV
+	ora CINV+1
+	beq !+
+	jmp (CINV)
+!:
+	// Vector not initialized - call default interrupt routine
+	jmp default_irq_handler
+
+irq_handler_brk:
+
+	// Store BRK adddress, to be displayed
+	sec
+	lda $0105, x
+	sbc #$02
+	sta CMP0+0
+	lda $0106, x
+	sbc #$00
+	sta CMP0+1
+
+	// Interrupt caused by BRK
+	jmp (CBINV)

src/kernal/interrupts/hw_entry_nmi.s

@@ -0,0 +1,23 @@
+// #LAYOUT# STD *        #TAKE
+// #LAYOUT# *   KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+
+hw_entry_nmi:
+
+	sei                      // do not allow IRQ to interfere, see https://www.c64-wiki.com/wiki/Interrupt
+
+#if CONFIG_CPU_MOS_6502 && CONFIG_BCD_SAFE_INTERRUPTS
+	cld                      // clear decimal flag to allow using it without disabling interrupts
+#endif
+
+	// Call interrupt routine (only if initialised)
+	pha
+	lda NMINV+1              // consider zeropage NMI address as uninitialized vector
+	beq !+                   // this allows safer interrupt vector modifications 
+	pla
+	jmp (NMINV)
+!:
+	// Vector not initialized - call default interrupt routine
+	pla
+	jmp default_nmi_handler

src/kernal/interrupts/nmi_lock.s

@@ -0,0 +1,60 @@
+// #LAYOUT# STD *        #TAKE
+// #LAYOUT# *   KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+//
+// Routine to lock NMI interrupts, using a trick described here:
+// - https://codebase64.org/doku.php?id=base:nmi_lock
+//
+
+
+#if CONFIG_TAPE_HEAD_ALIGN
+
+
+// XXX consider broader usage of this method to make IO safer
+
+
+nmi_lock:
+
+	// We will have to change NMI vector to point empty routine,
+	// which will not acknowledge the interrupt - thus preventing
+	// the NMI to be triggered again
+	
+	// Our code considers zeropage address invalid, so put
+	// it there as a preparation
+
+	ldx #$00
+	stx NMINV+1
+
+	// We can now safelly replace the vector
+
+	lda #<return_from_interrupt_rti
+	sta NMINV+0
+	lda #>return_from_interrupt_rti
+	sta NMINV+1
+
+	// Stop timer A
+
+    stx CIA2_CRA // $DD0E
+
+    // Set timer A to 0, after starting NMI will occur immediately
+
+	stx CIA2_TIMALO // $DD04
+	stx CIA2_TIMAHI // $DD05
+        
+	// Set timer A as source for NMI
+
+    lda #$81
+    sta CIA2_ICR // $DD0D
+
+    // Start timer A to trigger the NMI
+
+    lda #$01
+    sta CIA2_CRA // $DD0E
+
+    // All done. Unmaskable interrupts are now masked.
+
+    rts
+
+
+#endif