dev: added signon strings and some other basic bootup code

boot.asm

@@ -1,16 +1,18 @@
-; SPDX-License-Identifier: MPL-2.0
+	;        SPDX-License-Identifier: MPL-2.0
-; SPDX-FileCopyrightText: (c) 2025 A.M. Rowsell
+	;        SPDX-FileCopyrightText: (c) 2025 A.M. Rowsell
-.section "boot","acrx"
+	.section "boot", "acrx"
-.global zone_setup
+	.global  zone_setup
-.global os_warm_boot
+	.global  os_warm_boot
-.extern os_main_loop
+	.extern  os_main_loop
+
+	; ==================================
+	; This is the cold boot entry point!
+	; It is linked to land at 0xC3C3
+	; ==================================
 
-; ==================================
-; This is the cold boot entry point!
-; It is linked to land at 0xC3C3
-; ==================================
 _start:
 zone_setup:
+	ld a, ixl
 	ld sp, 0x6FFF
 	jp os_main_loop
 

zone.asm

@@ -4,33 +4,30 @@
 	;        ZONE OS main section
 	;        ============================================================
 	.section "zone", "acrx"
-	.global  zone_start
 	.global  os_print_vec
 	.global  os_getch_vec
 	.global  os_outbyte_vec
 	.global  os_inbyte_vec
 	.global  os_main_loop
+	.local   os_print_signon
 
 	.set UARTSTATUS, 6
 	.set UARTDATA, 7
 
-zone_start:
-	ret
-
 os_print_vec:
 	;    this takes a character in a and sends it to the UART
 	push af
 	push bc
 	push de
 	ld   d, a
-	ld   bc, UARTSTATUS
+	ld   c, UARTSTATUS
 
 $1:
 	in  a, (c); get status byte
 	bit 0, a; test bit 0
 	jr  z, $1; jump back if UART not ready
 	ld  a, d
-	ld  bc, UARTDATA
+	ld  c, UARTDATA
 	out (c), a; send byte to uart
 	pop de
 	pop bc
@@ -38,6 +35,17 @@ $1:
 	ret
 
 os_getch_vec:
+	;    this gets a character from the UART and puts in in a
+	push bc
+	ld   c, UARTSTATUS
+
+a2:
+	in  a, (c); get status byte
+	bit 1, a
+	jr  z, a2
+	ld  c, UARTDATA
+	in  a, (c)
+	pop bc
 	ret
 
 os_outbyte_vec:
@@ -63,13 +71,43 @@ os_inbyte_vec:
 	ret
 
 os_main_loop:
-	jp os_main_loop
+	call os_print_signon
+
+os_busy_loop:
+	jp os_busy_loop
+
+	; ======================
+	; non-vectored functions
+	; ======================
+
+os_print_signon:
+	ld hl, zoneSignon
+	ld a, (hl)
+
+$2:
+	call os_print_vec
+	inc  hl
+	ld   a, (hl)
+	jr   nz, $2
+
+$3:
+	ld hl, zoneCopyright
+	ld a, (hl)
+
+$4:
+	call os_print_vec
+	inc  hl
+	ld   a, (hl)
+	jr   nz, $4
+	ret
 
 zoneSignon:
-	.string "ZONE OS ver. 0.01"
+	.byte "ZONE OS ver. 0.01"
+	.byte 10, 13, 0
 
 zoneCopyright:
-	.string "(c) A.M. Rowsell, license MPLv2"
+	.byte "(c) A.M. Rowsell, license MPLv2"
+	.byte 10, 13, 0
 
 zonePrompt:
 	.string "z] "