parse_command refactor

src/base85a.S

@@ -89,7 +89,7 @@ base85_encode:
 	.global mul85
 mul85:
 	# endif
-
+	;; TODO for SPACE: inline this
 _mul85:
 	ldi r21, 85
 	mul r25, r21

src/cmd.c

@@ -11,14 +11,7 @@
 #include "pipe.h"
 
 uint8_t cmd_buffer[16];
-uint8_t cmd_buffer_valid;
+uint8_t flash_buffer_valid;
-
-static __attribute__((noinline))
-const uint8_t *skip_space(const uint8_t *s) {
-	if (*s == ' ')
-		s++;
-	return s;
-}
 
 uint8_t base85_str[6];
 #if 0
@@ -69,23 +62,11 @@ void base85_send_buffer(const uint8_t *buf)
 static inline
 const uint8_t *base85_fill_buffer(const uint8_t *s) {
 	base85_error = 0;
-	s = skip_space(s);
 	for (int i=0; !base85_error && i<FB_SIZE; i+=4)
 		s = base85_decode(s, (uint32_t *)(cmd_buffer + i));
-	s = skip_space(s);
 	return s;
 }
 
-static inline
-void bch4369_feed_buffer(uint8_t flag)
-{
-	if (flag=='0') {
-		memset(bch_parity, 0, 16);
-	}
-	bch4369_str(cmd_buffer,16);
-}
-
-
 uint8_t * poke_addr;
 uint8_t peek_size;
 struct peak_poke {
@@ -132,95 +113,122 @@ uint8_t poke(struct peak_poke *p, uint8_t hp, uint8_t poke)
 	return s && !poke;
 }
 
+const uint8_t *cmd_flags;
+#if 0
+static __attribute__((noinline))
+uint8_t cmd_flag(uint8_t f)
+{
+	if (*cmd_flags == f) {
+		cmd_flags++;
+		send_char(f);
+		return f;
+	}
+	return 0;
+}
+#else
+static __attribute__((noinline, naked))
+uint8_t cmd_flag(uint8_t f)
+{
+	// _send_char22 does not gobble r24.
+	__asm__(
+	""
+	"lds	r30, cmd_flags"		"\n\t"
+	"lds	r31, cmd_flags+1"	"\n\t"
+	"ld	r22, Z+"		"\n\t"
+	"cp	r22, r24"		"\n\t"
+	"mov	r24, r1"		"\n\t"
+	"brne 9f"			"\n\t"
+	"mov	r24, r22"		"\n\t"
+	"sts	cmd_flags, r30"		"\n\t"
+	"sts	cmd_flags+1, r31"	"\n\t"
+	"rcall 	_send_char22"		"\n"
+	"9:"				"\n\t"
+	"ret"				"\n"
+	);
+}
+#endif
+
 void parse_command(const uint8_t *s, uint8_t n)
 {
+	// ^[A-Z][!-@]+( [!-u]{20}])?$
+	// cmd   flags   base85
+
+	uint8_t r = 0;
 	uint8_t cmd = *s++;
-	if (*s =='`')
+	if (cmd < 'A' || cmd > 'Z')
 		return;
-	uint8_t r = 0x08|cmd;
+	send_char('#');
-	send_char('`');
 	send_char(cmd);
-	uint8_t have_b = !(cmd & 0x20);
+	uint8_t bflg = *s - '0';
-	cmd |= 0x20;
+	uint8_t *bptr = cmd_buffer;
-	if (cmd > 'z')
+	if (bflg <= 5) {
-		goto error;
+		bptr = flash_buffer + 16*bflg;
-	if (have_b) {
+		bflg = 1<<bflg;
-		s = base85_fill_buffer(s);
+		s++;
+	}
+	else
+		bflg = 0;
+	cmd_flags = s;
+	while (*s > ' ' && *s < 'A')
+		s++;
+	uint8_t have_b = 0;
+	if (*s==' ') {
+		s = base85_fill_buffer(s+1);
 		if (base85_error) {
 			r = base85_error;
 			goto error;
 		}
-		cmd_buffer_valid |= 0x80;
+		have_b = 1;
 	}
-	s = skip_space(s);
+	if (*s != '\n')
-	uint8_t flag = *s++;
+		goto error;
 	switch(cmd) {
-	case 'a':
+	case 'A':
 		r = adc_current;
 		if (r >= N_ADC) {
-			if (flag=='=') {
+			if (cmd_flag('<'))
-				memcpy(cmd_buffer, adc_readings, 16);
-				cmd_buffer_valid |= 0x40;
-				flag = *s++;
-			}
-			if (flag == '<') {
 				base85_send_buffer((void*)adc_readings);
-				flag = *s++;
+			if (cmd_flag('!'))
-			}
-			if (flag == '+')
 				start_adc();
 		}
 		break;
-	case 'b':
+	case 'B':
-		r = cmd_buffer_valid;
+		if (have_b && bflg) {
-		if (have_b) {
+			if (cmd_flag('|'))
-			flag -= '0';
+				flash_buffer_valid |= bflg;
-			if (flag < 5 && flag==cmd_buffer_valid) {
+			memcpy(bptr, cmd_buffer, 16);
-				memcpy(flash_buffer+16*flag, cmd_buffer, 16);
-				r = cmd_buffer_valid |= 1<<flag;
-				flag = *++s;
-			}
 		}
-		if (flag == '%') {
+		if (cmd_flag('%')) {
-			if (*s=='<')
+			if (cmd_flag('!'))
-				base85_send_buffer(bch_parity);
+				memset(bch_parity, 0, 16);
-			if (have_b)
+			bch4369_str(bptr, 16);
-				bch4369_feed_buffer(*++s);
 		}
-		else if (flag == '<') {
+		if (cmd_flag('<')) {
-			flag = *s - '0';
+			if (cmd_flag('|'))
-			uint8_t *b;
+				flash_buffer_valid &=~ bflg;
-			if (flag < 5)
+			base85_send_buffer(bptr);
-				b = flash_buffer + 16*flag;
-			else {
-				b = cmd_buffer;
-			}
-			base85_send_buffer(b);
 		}
+		r = flash_buffer_valid;
 		break;
-	case 'f':
+	case 'F':
-		if (have_b) {
+		if (have_b)
 			r = flash_submit_command(cmd_buffer);
-			cmd_buffer_valid &=~ 0x80;
-		}
 		else
-			r = flash_poll(flag=='!');
+			r = flash_poll(cmd_flag('!'));
 		break;
-	case 'p':
+	case 'P':
-		if (have_b) {
+		if (have_b)
-			r = pipe_config(cmd_buffer, flag);
+			r = pipe_config(cmd_buffer);
-			cmd_buffer_valid &= ~0x80;
-		}
 		else
-			r = pipe_poll(flag=='!');
+			r = pipe_poll(cmd_flag('!'));
 		break;
-	case 'm':
+	case 'M':
-		if (poke((void*)cmd_buffer, have_b, have_b && flag=='!'))
+		if (poke((void*)cmd_buffer, have_b, have_b && cmd_flag('!')))
 			base85_send_buffer(cmd_buffer);
+		break;
 	default:
 	error:
 		send_char('?');
 	}
 	send_hex_byte_eol(r);
 }
-

src/flash.c

@@ -264,12 +264,6 @@ void bch_flash_init()
 uint8_t flash_poll(uint8_t rr)
 {
 	uint8_t r = fs.status;
-	if (spi_busy_p()) {
-		if (rr)
-			goto collision;
-		fs.status = r | FS_Busy;
-		return r;
-	}
 	if ((r & FS_Error) == FS_Error)
 		return r;
 	if (r & FS_StBsy) {
@@ -285,7 +279,6 @@ uint8_t flash_poll(uint8_t rr)
 	if (!(r & FS_Busy))
 	    goto ready;
 	if (rr) {
-	collision:
 		r |= FS_Error;
 		fs.status = r;
 		return r;
@@ -311,11 +304,12 @@ uint8_t flash_poll(uint8_t rr)
 	}
 
 ready:
+	r &= ~(FS_Busy | FS_StBsy);
 	if (rr)
 		r |= FS_Ack;
-	// clear the Bsy bits
-	r &= ~(FS_Busy | FS_StBsy);
 	fs.status = r;
+	if (spi_busy_p())
+		return r;
 	if (r & FS_Dir == FS_Write && fs.block == 8)
 		flash_burn_page();
 	else if (!flash_stream_done()) {
@@ -331,6 +325,7 @@ ready:
 		}
 		else if (r & FS_Dir == FS_Erase)
 			flash_erase_next_page();
+		fs.status &=~ FS_Ack;
 	}
 	return fs.status;
 }

src/pipe.c

@@ -1,5 +1,6 @@
 
-#include <pipe.h>
+#include "pipe.h"
+#include "flash.h"
 
 struct pipe pipe;
 
@@ -11,12 +12,15 @@ struct pipe_config {
 	uint8_t flash_page;
 };
 
-uint8_t pipe_config(const uint8_t *, uint8_t flag)
+uint8_t pipe_config(const uint8_t *)
 {
 	return 0;
 }
 uint8_t pipe_poll(uint8_t flag)
 {
+	uint8_t r = pipe.status;
+	if (spi_busy_p() || flash_poll(0) & FS_Busy)
+		return r;
 	return 0;
 }
 

src/pipe.h

@@ -1,7 +1,7 @@
 
 #include <stdint.h>
 
-uint8_t pipe_config(const uint8_t *, uint8_t flag);
+uint8_t pipe_config(const uint8_t *);
 uint8_t pipe_poll(uint8_t flag);
 
 enum pipe_ports {

src/uart.c

@@ -51,7 +51,7 @@ ISR(USART0_DRE_vect)
 
 #else
 
-__attribute__ ((noinline, noclone))
+__attribute__ ((noinline, naked))
 void tx()
 {
 	// This uses only three registers, to save stack in the ISR.
@@ -76,13 +76,13 @@ void tx()
 		"	lds	r31, uart_tx_w				\n"
 		"	cp	r30, r31				\n"
 		"	breq 3f						\n"
-		"	lds 	r30, %[STATUS]				\n"
+		"	lds 	r31, %[STATUS]				\n"
-		"	sbrc 	r30, %[DRE]				\n"
+		"	sbrc 	r31, %[DRE]				\n"
 		"	rjmp 1b						\n"
 		"	ori	r25, 1<<%[DRE]				\n"
 		"3:							\n"		
 		"	sts 	%[CTRLA], r25				\n"
-		"	sts 	uart_tx_r, r21				\n"
+		"	ret						\n"
 		:
 		:
 		[TXC] "n" (USART_TXCIF_bp),
@@ -96,8 +96,7 @@ void tx()
 
 ISR(USART0_DRE_vect, ISR_NAKED)
 {
-	// Doing this naked is a bit dangerous,
+	// This saves five instructions and two bytes stack (r0, r1).
-	// but saves five instructions and two bytes stack (r0, r1).
 	// OTOH, the C implementation of tx() is not bad either,
 	// if we are doing this asm, then we do it agressively.
 	__asm__("\n"

src/uart_tx.S

@@ -9,6 +9,7 @@
 	.global send_hex_byte
 	.global send_hex_byte_eol
 	.global send_char
+	.global _send_char22
 	.global send_str
 	.global _send_str26
 	.global uart_busy
@@ -17,37 +18,16 @@
 
 // `tx()` and `put_char()` do not gobble r18, r20, r21, r22, r24, r26, and r27.
 	
-put_char:
+// r18, r26, and 27 must be preseved in the hex functions
-	// non-global, non-C
+// …, r20, r21, r24,  must be preserved in `uart_busy()` and `put_char()'
-	// arg: char r22 
-	lds 	r23, uart_tx_r
-	lds 	r30, uart_tx_w
-	ldi	r19, 1
-	add	r19, r30
-	eor	r23, r19
-	andi 	r30, 0x1f // uart_tx_m
-	ldi	r31, 0
-	subi 	r30, lo8(-(uart_tx))
-	sbci 	r31, hi8(-(uart_tx))
-	andi	r23, 0x1f // uart_tx_m
-	breq 1f
-	st 	Z, r22
-	sts 	uart_tx_w, r19
-1:
-	// r22 preserved
-	// r23 full when zero
-	ret
-
-	// r18, r26, and 27 must be preseved in the hex functions
-	// …, r20, r21, r24,  must be preserved in `uart_busy()` and `put_char()'
 
 send_hex_byte_eol:
 	ldi	r22, ' '
-	rcall	send_char22
+	rcall	_send_char22
 	rcall	send_hex_byte
 send_eol:	
 	ldi	r22, '\n'
-	rcall	send_char22
+	rcall	_send_char22
 uart_busy:
 	cli
 	rcall	tx	; gobbles r25, r30, and r31
@@ -57,11 +37,13 @@ uart_busy:
 9:
 	ret
 
+#ifdef HEX_WORD
 send_hex_word:
 	mov	r20, r24
 	mov	r24, r25
 	rcall	send_hex_byte
 	mov	r24, r20
+#endif
 send_hex_byte:
 	mov	r21, r24
 	swap	r24
@@ -75,24 +57,43 @@ send_hex_nibble:
 	subi	r24, '9'+1-'A'
 send_char:
 	mov	r22, r24
-send_char22:	
+	rjmp	_send_char22
-	rcall	put_char
+1:
-	brne	9f
 	rcall	uart_busy
 	sleep
-	rjmp	send_char22
+_send_char22:
+	// non-global, non-C
+	// arg: char r22
+	lds 	r23, uart_tx_r
+	lds 	r30, uart_tx_w
+	ldi	r19, 1
+	add	r19, r30
+	sub	r23, r19
+	andi 	r30, 0x1f // uart_tx_m
+	ldi	r31, 0
+	subi 	r30, lo8(-(uart_tx))
+	sbci 	r31, hi8(-(uart_tx))
+	subi	r23, 0xe0
+	brcs 1b
+	st 	Z, r22
+	sts 	uart_tx_w, r19
+9:
+	ret
 
 send_str:
 	movw	r26, r24
 	rjmp _send_str26
 1:
-	rcall	send_char22
+__send_char22_str26:
+	rcall	_send_char22
 _send_str26:
 	ld 	r22, X+
 	tst	r22
 	brne 1b
+9:
 	ret
 
+#ifdef SEND_HEX
 send_hex:
 	movw	r26, r24
 	mov	r18, r22
@@ -103,6 +104,7 @@ send_hex:
 	brcc	1b
 9:
 	ret
+#endif
 
 command:
 	;; when any frame errors occured, dismiss the buffer