From af7fb6b5fa5175172aea21898d1e8ea9ad87af9c Mon Sep 17 00:00:00 2001
From: FeralChild64 <you@example.com>
Date: Fri, 29 Jan 2021 19:11:17 +0100
Subject: [PATCH] Z80TEST.COM loading code complete, not tested yet

---
 src/zvm_m65/,aliases_zvm.s  | 14 +++++--
 src/zvm_m65/z80_table_gen.s |  3 +-
 src/zvm_m65/zvm.s           | 10 +++--
 src/zvm_m65/zvm_cputest.s   | 84 ++++++++++++++++++++++++++++++++-----
 4 files changed, 93 insertions(+), 18 deletions(-)

diff --git a/src/zvm_m65/,aliases_zvm.s b/src/zvm_m65/,aliases_zvm.s
index bf263170..845a30a7 100644
--- a/src/zvm_m65/,aliases_zvm.s
+++ b/src/zvm_m65/,aliases_zvm.s
@@ -73,9 +73,17 @@
 ; BIOS data
 ;
 
-!addr VEC_MOVE_fetch         = $40               ; 2 bytes - vector to byte fetch routine, for BIOS routine MOVE
-!addr VEC_MOVE_store         = $42               ; 2 bytes - vector to byte store routine, for BIOS routine MOVE
-!addr VEC_DISKIO_store       = $44               ; 2 bytes - vector to byte store routine, for BIOS disk I/O operations
+; Reuse data for loading
+
+!addr BIOS_IOBUFERPTR        = $40               ; 4 bytes - pointer to hardware I/O buffer
+!addr BIOS_LOADPTR           = $44               ; 4 bytes - pointer for loading data
+!addr BIOS_LOADCOUNT         = $48               ; 2 bytes - counter used for loading data
+
+; XXX are the values below needed?
+
+!addr VEC_MOVE_fetch         = $4A               ; 2 bytes - vector to byte fetch routine, for BIOS routine MOVE
+!addr VEC_MOVE_store         = $4C               ; 2 bytes - vector to byte store routine, for BIOS routine MOVE
+!addr VEC_DISKIO_store       = $4E               ; 2 bytes - vector to byte store routine, for BIOS disk I/O operations
 
 
 ;
diff --git a/src/zvm_m65/z80_table_gen.s b/src/zvm_m65/z80_table_gen.s
index 5bce535d..fa52c7b7 100644
--- a/src/zvm_m65/z80_table_gen.s
+++ b/src/zvm_m65/z80_table_gen.s
@@ -3,7 +3,8 @@
 ; Z80 emulator - precalculated data generator
 ;
 
-z80_table_gen:
+
+Z80_table_gen:
 
 	jsr PRIMM
 	!pet $0D, "Generating CPU tables... "
diff --git a/src/zvm_m65/zvm.s b/src/zvm_m65/zvm.s
index 3827ae41..e22212b7 100644
--- a/src/zvm_m65/zvm.s
+++ b/src/zvm_m65/zvm.s
@@ -53,9 +53,11 @@ ZVM: ; entry point
 
 	; XXX enable test jsr ZVM_memtest
 
-	; Generate CPU tables
+	; Generate CPU tables, reset the CPU
 
-	jsr z80_table_gen
+	jsr Z80_table_gen
+	jsr Z80_reset
+	; XXX Z80 clear memory here
 
 	; Try CPU test
 
@@ -66,7 +68,7 @@ ZVM: ; entry point
 	; XXX code is not ready to progress further
 	jsr PRIMM
 	!pet $0D, "Implementation not finished yet.", 0
-	jmp ZVM_halt
+	jmp ZVM_syshalt
 
 	jmp zvm_BIOS_00_BOOT
 
@@ -134,7 +136,7 @@ ZVM_halt_memtest_failed:
 
 	; FALLTROUGH
 
-ZVM_halt:
+ZVM_syshalt:
 
 	jsr PRIMM
 	!pet "   * System HALTED *", 0
diff --git a/src/zvm_m65/zvm_cputest.s b/src/zvm_m65/zvm_cputest.s
index d924145e..d34833a3 100644
--- a/src/zvm_m65/zvm_cputest.s
+++ b/src/zvm_m65/zvm_cputest.s
@@ -6,6 +6,8 @@
 
 ZVM_cputest:
 
+	; XXX move loading code to separate routine(s)
+
 	; Copy file name to RAM
 
 	ldx #$FF
@@ -24,14 +26,14 @@ ZVM_cputest:
 	lda #$2E                           ; dos_setname
 	sta HTRAP00
 	+nop                               ; required by hypervisor
-	bcc @end
+	+bcc @end
 
 	; Try to find the file
 
 	lda #$34
 	sta HTRAP00
 	+nop
-	bcc @end
+	+bcc @end
 
 	jsr PRIMM
 	!pet "Loading 'Z80TEST.COM'... ", 0
@@ -51,32 +53,94 @@ ZVM_cputest:
 	lda #$80
 	tsb $D689 ; XXX invent name for the register
 
+	; Prepare pointers
+
+	lda #$FF
+	sta BIOS_IOBUFERPTR+3
+	lda #$D6
+	sta BIOS_IOBUFERPTR+2
+
+	lda #$FF
+	sta BIOS_IOBUFERPTR+3
+	lda #$D6
+	sta BIOS_IOBUFERPTR+2
+
+	lda #$00
+	sta BIOS_LOADPTR+3
+	lda #$05
+	sta BIOS_LOADPTR+2
+	lda #$01
+	sta BIOS_LOADPTR+1
+	lda #$00
+	sta BIOS_LOADPTR+1
+
+!addr BIOS_LOADCOUNT         = $48               ; 2 bytes - counter used for loading data
+
+
 	; Read sectors
 
 @loop2:
 
+	; Set I/O buffer pointer to start
+
+	lda #$6E
+	sta BIOS_IOBUFERPTR+1
+	lda #$00
+	sta BIOS_IOBUFERPTR+0
+
+	; Read up to 512 bytes
+
 	lda #$1A
 	sta HTRAP00
 	+nop
 
-	; .X (low byte) and .Y (high byte) contain number of bytes read
+	; Copy data from buffer to memory
 
-	; XXX copy data from buffer at $FFD6E00
+	stx BIOS_LOADCOUNT+0
+	sty BIOS_LOADCOUNT+1
 
+	tya
+	ora BIOS_LOADCOUNT+0
+	beq @load_done
 
+@loop3:
 
-	; XXX finish the implementation
+	dew BIOS_LOADCOUNT
+	bmi @loop2
 
+	lda [BIOS_IOBUFERPTR],z
+	sta [BIOS_LOADPTR],z
+
+	inw BIOS_IOBUFERPTR
+	inw BIOS_LOADPTR
+
+	bra @loop3
+
+@load_done:
+
+	; At this moment we have Z80TEST.COM loaded into memory
+	; Install a virtual CP/M, set PC to $0100, and run it!
+
+	lda #$01
+	sta REG_PC+1
+	dec
+	sta BIOS_LOADPTR+1
+	lda #$05
+	sta BIOS_LOADPTR+0
+	lda #$76                           ; HALT
+	sta [BIOS_LOADPTR],z
+	inc BIOS_LOADPTR
+	lda #$FF
+	sta [BIOS_LOADPTR],z               ; $FF = CP/M simulation for CPU test
+
+	; Run the software
+
+	jmp ZVM_next
 
 @end:
 
 	rts
 
-
-
-
-
-
 ZVM_filename_Z80TEST:
 
 	!pet "z80test.com", 0