stdio: remove a layer of indirection in GetC/PutC

We use zasm's ability to use labels in .equ directive.

We didn't do it before because for a while, we were in between scas
and zasm (scas was used in automated tests) so we needed to use the
lowest common denominator: zasm doesn't have macros and scas can't
use labels in .equ directives.

This forced us to add this layer of indirection. But now that we are
completely cut from scas' dependency, we can use this nice zasm's
ability.

doc/glue-code.md

@@ -7,47 +7,43 @@ look like:
 
 
     ; The RAM module is selected on A15, so it has the range 0x8000-0xffff
-    .equ    RAMSTART	0x8000
-    .equ    RAMEND		0xffff
-    .equ    ACIA_CTL	0x80	; Control and status. RS off.
-    .equ    ACIA_IO		0x81	; Transmit. RS on.
+    .equ	RAMSTART	0x8000
+    .equ	RAMEND		0xffff
+    .equ	ACIA_CTL	0x80	; Control and status. RS off.
+    .equ	ACIA_IO		0x81	; Transmit. RS on.
 
-        jr init
+    jp	init
 
     ; interrupt hook
     .fill	0x38-$
-        jp aciaInt
+    jp	aciaInt
+
+    .inc "err.h"
+    .inc "core.asm"
+    .inc "parse.asm"
+    .equ	ACIA_RAMSTART	RAMSTART
+    .inc "acia.asm"
+
+    .equ	STDIO_RAMSTART	ACIA_RAMEND
+    .equ	STDIO_GETC	aciaGetC
+    .equ	STDIO_PUTC	aciaPutC
+    .inc "stdio.asm"
+
+    .equ	SHELL_RAMSTART	STDIO_RAMEND
+    .equ	SHELL_EXTRA_CMD_COUNT 0
+    .inc "shell.asm"
 
     init:
         di
         ; setup stack
-        ld hl, RAMEND
-        ld sp, hl
+        ld	hl, RAMEND
+        ld	sp, hl
         im 1
-        call aciaInit
-        xor	a
-        ld	de, BLOCKDEV_SEL
-        call	blkSel
-        call	stdioInit
-        call    shellInit
+
+        call	aciaInit
+        call	shellInit
         ei
-        jp      shellLoop
-
-    #include "core.asm"
-    .equ    ACIA_RAMSTART	RAMSTART
-    #include "acia.asm"
-    .equ	BLOCKDEV_RAMSTART	ACIA_RAMEND
-    .equ	BLOCKDEV_COUNT		1
-    #include "blockdev.asm"
-    ; List of devices
-    .dw	aciaGetC, aciaPutC, 0, 0
-
-    .equ	STDIO_RAMSTART	BLOCKDEV_RAMEND
-    #include "stdio.asm"
-
-    .equ    SHELL_RAMSTART	STDIO_RAMEND
-    .equ    SHELL_EXTRA_CMD_COUNT 0
-    #include "shell.asm"
+        jp	shellLoop
 
 Once this is written, building it is easy: 
 

kernel/stdio.asm

@@ -4,13 +4,17 @@
 ; in", that is, the console through which the user is connected in a decoupled
 ; manner.
 ;
-; Those GetC/PutC routines are hooked in during stdioInit and have this API:
+; Those GetC/PutC routines are hooked through defines and have this API:
 ;
 ; GetC: Blocks until a character is read from the device and return that
 ;       character in A.
 ;
 ; PutC: Write character specified onto the device.
 ;
+; *** Defines ***
+; STDIO_GETC: address of a GetC routine
+; STDIO_PUTC: address of a PutC routine
+; 
 ; *** Consts ***
 ; Size of the readline buffer. If a typed line reaches this size, the line is
 ; flushed immediately (same as pressing return).
@@ -19,8 +23,6 @@
 ; *** Variables ***
 ; Used to store formatted hex values just before printing it.
 .equ	STDIO_HEX_FMT	STDIO_RAMSTART
-.equ	STDIO_GETC	@+2
-.equ	STDIO_PUTC	@+2
 
 ; Line buffer. We read types chars into this buffer until return is pressed
 ; This buffer is null-terminated.
@@ -29,19 +31,11 @@
 ; Index where the next char will go in stdioGetC.
 .equ	STDIO_RAMEND	@+STDIO_BUFSIZE
 
-; Sets GetC to the routine where HL points to and PutC to DE.
-stdioInit:
-	ld	(STDIO_GETC), hl
-	ld	(STDIO_PUTC), de
-	ret
-
 stdioGetC:
-	ld	ix, (STDIO_GETC)
-	jp	(ix)
+	jp	STDIO_GETC
 
 stdioPutC:
-	ld	ix, (STDIO_PUTC)
-	jp	(ix)
+	jp	STDIO_PUTC
 
 ; print null-terminated string pointed to by HL
 printstr:
@@ -52,7 +46,7 @@ printstr:
 	ld	a, (hl)		; load character to send
 	or	a		; is it zero?
 	jr	z, .end		; if yes, we're finished
-	call	stdioPutC
+	call	STDIO_PUTC
 	inc	hl
 	jr	.loop
 
@@ -67,7 +61,7 @@ printnstr:
 	push	hl
 .loop:
 	ld	a, (hl)		; load character to send
-	call	stdioPutC
+	call	STDIO_PUTC
 	inc	hl
 	djnz	.loop
 
@@ -79,9 +73,9 @@ printnstr:
 printcrlf:
 	push	af
 	ld	a, ASCII_CR
-	call	stdioPutC
+	call	STDIO_PUTC
 	ld	a, ASCII_LF
-	call	stdioPutC
+	call	STDIO_PUTC
 	pop	af
 	ret
 
@@ -119,7 +113,7 @@ stdioReadLine:
 	ld	b, STDIO_BUFSIZE-1
 .loop:
 	; Let's wait until something is typed.
-	call	stdioGetC
+	call	STDIO_GETC
 	; got it. Now, is it a CR or LF?
 	cp	ASCII_CR
 	jr	z, .complete	; char is CR? buffer complete!
@@ -131,7 +125,7 @@ stdioReadLine:
 	jr	z, .delchr
 
 	; Echo the received character right away so that we see what we type
-	call	stdioPutC
+	call	STDIO_PUTC
 
 	; Ok, gotta add it do the buffer
 	ld	(hl), a
@@ -159,9 +153,9 @@ stdioReadLine:
 	; Char deleted in buffer, now send BS + space + BS for the terminal
 	; to clear its previous char
 	ld	a, ASCII_BS
-	call	stdioPutC
+	call	STDIO_PUTC
 	ld	a, ' '
-	call	stdioPutC
+	call	STDIO_PUTC
 	ld	a, ASCII_BS
-	call	stdioPutC
+	call	STDIO_PUTC
 	jr	.loop

recipes/rc2014/eeprom/glue.asm

@@ -27,6 +27,8 @@ jp	aciaInt
 .dw	mmapGetB, mmapPutB
 
 .equ	STDIO_RAMSTART	BLOCKDEV_RAMEND
+.equ	STDIO_GETC	aciaGetC
+.equ	STDIO_PUTC	aciaPutC
 .inc "stdio.asm"
 
 .equ	AT28W_RAMSTART	STDIO_RAMEND
@@ -49,9 +51,6 @@ init:
 	im 1
 
 	call	aciaInit
-	ld	hl, aciaGetC
-	ld	de, aciaPutC
-	call	stdioInit
 	call	shellInit
 
 	xor	a

recipes/rc2014/glue.asm

@@ -18,6 +18,8 @@ jp	aciaInt
 .inc "acia.asm"
 
 .equ	STDIO_RAMSTART	ACIA_RAMEND
+.equ	STDIO_GETC	aciaGetC
+.equ	STDIO_PUTC	aciaPutC
 .inc "stdio.asm"
 
 .equ	SHELL_RAMSTART	STDIO_RAMEND
@@ -32,9 +34,6 @@ init:
 	im 1
 
 	call	aciaInit
-	ld	hl, aciaGetC
-	ld	de, aciaPutC
-	call	stdioInit
 	call	shellInit
 	ei
 	jp	shellLoop

recipes/rc2014/ps2/glue.asm

@@ -16,6 +16,8 @@ jp	init
 .inc "kbd.asm"
 
 .equ	STDIO_RAMSTART	KBD_RAMEND
+.equ	STDIO_GETC	kbdGetC
+.equ	STDIO_PUTC	aciaPutC
 .inc "stdio.asm"
 
 .equ	SHELL_RAMSTART	STDIO_RAMEND
@@ -30,9 +32,6 @@ init:
 
 	call	aciaInit
 	call	kbdInit
-	ld	hl, kbdGetC
-	ld	de, aciaPutC
-	call	stdioInit
 	call	shellInit
 	jp	shellLoop
 

recipes/rc2014/sdcard/glue.asm

@@ -34,6 +34,8 @@ jp	aciaInt
 
 
 .equ	STDIO_RAMSTART	BLOCKDEV_RAMEND
+.equ	STDIO_GETC	aciaGetC
+.equ	STDIO_PUTC	aciaPutC
 .inc "stdio.asm"
 
 .equ	FS_RAMSTART	STDIO_RAMEND
@@ -66,9 +68,6 @@ init:
 	ld	sp, hl
 	im	1
 	call	aciaInit
-	ld	hl, aciaGetC
-	ld	de, aciaPutC
-	call	stdioInit
 	call	fsInit
 	call	shellInit
 	ld	hl, pgmShellHook

recipes/rc2014/zasm/glue.asm

@@ -65,6 +65,8 @@ jp	aciaInt
 .inc "mmap.asm"
 
 .equ	STDIO_RAMSTART	BLOCKDEV_RAMEND
+.equ	STDIO_GETC	aciaGetC
+.equ	STDIO_PUTC	aciaPutC
 .inc "stdio.asm"
 
 .equ	FS_RAMSTART	STDIO_RAMEND
@@ -99,9 +101,6 @@ init:
 	ld	sp, hl
 	im	1
 	call	aciaInit
-	ld	hl, aciaGetC
-	ld	de, aciaPutC
-	call	stdioInit
 	call	fsInit
 	call	shellInit
 	ld	hl, pgmShellHook

recipes/sms/glue.asm

@@ -19,6 +19,8 @@
 .inc "sms/vdp.asm"
 
 .equ	STDIO_RAMSTART	VDP_RAMEND
+.equ	STDIO_GETC	padGetC
+.equ	STDIO_PUTC	vdpPutC
 .inc "stdio.asm"
 
 .equ	SHELL_RAMSTART	STDIO_RAMEND
@@ -33,10 +35,6 @@ init:
 
 	call	padInit
 	call	vdpInit
-
-	ld	hl, padGetC
-	ld	de, vdpPutC
-	call	stdioInit
 	call	shellInit
 	jp	shellLoop
 

recipes/sms/kbd/glue.asm

@@ -21,6 +21,8 @@
 .inc "sms/vdp.asm"
 
 .equ	STDIO_RAMSTART	VDP_RAMEND
+.equ	STDIO_GETC	kbdGetC
+.equ	STDIO_PUTC	vdpPutC
 .inc "stdio.asm"
 
 .equ	SHELL_RAMSTART	STDIO_RAMEND
@@ -45,10 +47,6 @@ init:
 
 	call	kbdInit
 	call	vdpInit
-
-	ld	hl, kbdGetC
-	ld	de, vdpPutC
-	call	stdioInit
 	call	shellInit
 	jp	shellLoop
 

recipes/sms/romasm/glue.asm

@@ -52,6 +52,8 @@
 .inc "sms/vdp.asm"
 
 .equ	STDIO_RAMSTART	VDP_RAMEND
+.equ	STDIO_GETC	kbdGetC
+.equ	STDIO_PUTC	vdpPutC
 .inc "stdio.asm"
 
 .equ	MMAP_START	0xd700
@@ -104,9 +106,6 @@ init:
 	ld	a, 'S'
 	ld	(hl), a
 
-	ld	hl, kbdGetC
-	ld	de, vdpPutC
-	call	stdioInit
 	call	fsInit
 	xor	a
 	ld	de, BLOCKDEV_SEL

tools/emul/shell/shell_.asm

@@ -58,6 +58,8 @@
 .inc "mmap.asm"
 
 .equ	STDIO_RAMSTART	BLOCKDEV_RAMEND
+.equ	STDIO_GETC	emulGetC
+.equ	STDIO_PUTC	emulPutC
 .inc "stdio.asm"
 
 .equ	FS_RAMSTART	STDIO_RAMEND
@@ -84,9 +86,6 @@ init:
 	; setup stack
 	ld	hl, KERNEL_RAMEND
 	ld	sp, hl
-	ld	hl, emulGetC
-	ld	de, emulPutC
-	call	stdioInit
 	call	fsInit
 	ld	a, 0	; select fsdev
 	ld	de, BLOCKDEV_SEL

tools/emul/zasm/glue.asm

@@ -45,6 +45,8 @@ jp	printstr
 .dw	fsdevGetB, fsdevPutB
 
 .equ	STDIO_RAMSTART	BLOCKDEV_RAMEND
+.equ	STDIO_GETC	noop
+.equ	STDIO_PUTC	stderrPutC
 .inc "stdio.asm"
 
 .equ	FS_RAMSTART	STDIO_RAMEND
@@ -55,9 +57,6 @@ init:
 	di
 	ld	hl, 0xffff
 	ld	sp, hl
-	ld	hl, unsetZ
-	ld	de, stderrPutC
-	call	stdioInit
 	ld	a, 2	; select fsdev
 	ld	de, BLOCKDEV_SEL
 	call	blkSel