Add "avr/" includes folder

Also, add a "real world" example in AVRA tests, a blink program on
a ATtiny45. Some instructions are commented out because they aren't
implemented yet, but not many.

The output of the program has been verified against AVRA's own
output.

avr/README.md

@@ -0,0 +1,16 @@
+# AVR include files
+
+This folder contains header files that can be included in AVR assembly code.
+
+These definitions are organized in a manner that is very similar to other
+modern AVR assemblers, but most bits definitions (`PINB4`, `WGM01`, etc.) are
+absent. This is because there's a lot of them, each symbol takes memory during
+assembly and machines doing the assembling might be tight in memory. AVR code
+post collapse will have to take the habit of using numerical masks accompanied
+by comments describing associated symbols.
+
+To avoid repeats, those includes are organized in 3 levels. First, there's the
+`avr.h` file containing definitions common to all AVR models. Then, there's the
+"family" file containing definitions common to a "family" (for example, the
+ATtiny 25/45/85). Those definitions are the beefiests. Then, there's the exact
+model file, which will typically contain RAM and Flash boundaries.

avr/avr.h

@@ -0,0 +1,17 @@
+; *** CPU registers aliases ***
+
+.equ	XH	27
+.equ	XL	26
+.equ	YH	29
+.equ	YL	28
+.equ	ZH	31
+.equ	ZL	30
+
+.equ	SREG_C	0	; Carry Flag
+.equ	SREG_Z	1	; Zero Flag
+.equ	SREG_N	2	; Negative Flag
+.equ	SREG_V	3	; Two's Complement Overflow Flag
+.equ	SREG_S	4	; Sign Bit
+.equ	SREG_H	5	; Half Carry Flag
+.equ	SREG_T	6	; Bit Copy Storage
+.equ	SREG_I	7	; Global Interrupt Enable

avr/tn25.h

@@ -0,0 +1,10 @@
+.equ	FLASHEND	0x03ff	; Note: Word address
+.equ	IOEND		0x003f
+.equ	SRAM_START	0x0060
+.equ	SRAM_SIZE	128
+.equ	RAMEND		0x00df
+.equ	XRAMEND		0x0000
+.equ	E2END		0x007f
+.equ	EEPROMEND	0x007f
+.equ	EEADRBITS	7
+

avr/tn254585.h

@@ -0,0 +1,74 @@
+; *** Registers ***
+
+.equ	SREG	0x3f
+.equ	SPH	0x3e
+.equ	SPL	0x3d
+.equ	GIMSK	0x3b
+.equ	GIFR	0x3a
+.equ	TIMSK	0x39
+.equ	TIFR	0x38
+.equ	SPMCSR	0x37
+.equ	MCUCR	0x35
+.equ	MCUSR	0x34
+.equ	TCCR0B	0x33
+.equ	TCNT0	0x32
+.equ	OSCCAL	0x31
+.equ	TCCR1	0x30
+.equ	TCNT1	0x2f
+.equ	OCR1A	0x2e
+.equ	OCR1C	0x2d
+.equ	GTCCR	0x2c
+.equ	OCR1B	0x2b
+.equ	TCCR0A	0x2a
+.equ	OCR0A	0x29
+.equ	OCR0B	0x28
+.equ	PLLCSR	0x27
+.equ	CLKPR	0x26
+.equ	DT1A	0x25
+.equ	DT1B	0x24
+.equ	DTPS	0x23
+.equ	DWDR	0x22
+.equ	WDTCR	0x21
+.equ	PRR	0x20
+.equ	EEARH	0x1f
+.equ	EEARL	0x1e
+.equ	EEDR	0x1d
+.equ	EECR	0x1c
+.equ	PORTB	0x18
+.equ	DDRB	0x17
+.equ	PINB	0x16
+.equ	PCMSK	0x15
+.equ	DIDR0	0x14
+.equ	GPIOR2	0x13
+.equ	GPIOR1	0x12
+.equ	GPIOR0	0x11
+.equ	USIBR	0x10
+.equ	USIDR	0x0f
+.equ	USISR	0x0e
+.equ	USICR	0x0d
+.equ	ACSR	0x08
+.equ	ADMUX	0x07
+.equ	ADCSRA	0x06
+.equ	ADCH	0x05
+.equ	ADCL	0x04
+.equ	ADCSRB	0x03
+
+
+; *** Interrupt vectors ***
+
+.equ	INT0addr	0x0001	; External Interrupt 0
+.equ	PCI0addr	0x0002	; Pin change Interrupt Request 0
+.equ	OC1Aaddr	0x0003	; Timer/Counter1 Compare Match 1A
+.equ	OVF1addr	0x0004	; Timer/Counter1 Overflow
+.equ	OVF0addr	0x0005	; Timer/Counter0 Overflow
+.equ	ERDYaddr	0x0006	; EEPROM Ready
+.equ	ACIaddr		0x0007	; Analog comparator
+.equ	ADCCaddr	0x0008	; ADC Conversion ready
+.equ	OC1Baddr	0x0009	; Timer/Counter1 Compare Match B
+.equ	OC0Aaddr	0x000a	; Timer/Counter0 Compare Match A
+.equ	OC0Baddr	0x000b	; Timer/Counter0 Compare Match B
+.equ	WDTaddr		0x000c	; Watchdog Time-out
+.equ	USI_STARTaddr	0x000d	; USI START
+.equ	USI_OVFaddr	0x000e	; USI Overflow
+
+.equ	INT_VECTORS_SIZE	15	; size in words

avr/tn45.h

@@ -0,0 +1,9 @@
+.equ	FLASHEND	0x07ff	; Note: Word address
+.equ	IOEND		0x003f
+.equ	SRAM_START	0x0060
+.equ	SRAM_SIZE	256
+.equ	RAMEND		0x015f
+.equ	XRAMEND		0x0000
+.equ	E2END		0x00ff
+.equ	EEPROMEND	0x00ff
+.equ	EEADRBITS	8

avr/tn85.h

@@ -0,0 +1,9 @@
+.equ	FLASHEND	0x0fff	; Note: Word address
+.equ	IOEND		0x003f
+.equ	SRAM_START	0x0060
+.equ	SRAM_SIZE	512
+.equ	RAMEND		0x025f
+.equ	XRAMEND		0x0000
+.equ	E2END		0x01ff
+.equ	EEPROMEND	0x01ff
+.equ	EEADRBITS	9

tools/tests/avra/blink_tn45.asm

@@ -0,0 +1,43 @@
+; TODO: implement instructions that are commented out
+; REGISTER USAGE
+;
+; R1: overflow counter
+; R16: tmp stuff
+
+.inc "avr.h"
+.inc "tn254585.h"
+.inc "tn45.h"
+
+main:
+	ldi	r16, RAMEND&0xff
+        out	SPL, r16
+        ldi	r16, RAMEND}8
+	out	SPH, r16
+
+        ;sbi     DDRB, 0
+        ;cbi     PORTB, 0
+
+	; To have a blinking delay that's visible, we have to prescale a lot.
+	; The maximum prescaler is 1024, which makes our TCNT0 increase
+	; 976 times per second, which means that it overflows 4 times per
+	; second.
+        in      r16, TCCR0B
+        ori     r16, 0x05	; CS00 + CS02 = 1024 prescaler
+        out     TCCR0B, r16
+
+	;clr	r1
+
+loop:
+	in	r16, TIFR	; TIFR0
+	sbrc	r16, 1		; is TOV0 flag clear?
+	rcall	toggle
+        rjmp    loop
+
+toggle:
+	ldi	r16, 0b00000010	; TOV0
+	out	TIFR, R16
+	inc	r1
+        ;cbi     PORTB, 0
+        sbrs    r1, 1		; if LED is on
+        ;sbi     PORTB, 0
+	ret

tools/tests/avra/blink_tn45.expected

@@ -0,0 +1 @@
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tools/tests/avra/runtests.sh

@@ -1,11 +1,12 @@
 #!/bin/sh -e
 
-AVRA=../../emul/zasm/avra
+ZASM=../../zasm.sh
+AVRINC=../../../avr
 
 cmpas() {
     FN=$1
     EXPECTED=$(xxd ${FN%.*}.expected)
-    ACTUAL=$(cat ${FN} | $AVRA | xxd)
+    ACTUAL=$(cat ${FN} | "${ZASM}" -a "${AVRINC}" | xxd)
     if [ "$ACTUAL" = "$EXPECTED" ]; then
         echo ok
     else

tools/zasm.sh

@@ -6,15 +6,22 @@
 # binary. For example, "zasm.sh -o 4f < foo.asm" assembles foo.asm as if it
 # started with the line ".org 0x4f00".
 
+# The -a flag makes us switch to the AVR assembler
+
 # readlink -f doesn't work with macOS's implementation
 # so, if we can't get readlink -f to work, try python with a realpath implementation
 ABS_PATH=$(readlink -f "$0" || python -c "import os; print(os.path.realpath('$0'))")
+DIR=$(dirname "${ABS_PATH}")
+ZASMBIN="${DIR}/emul/zasm/zasm"
 
-usage() { echo "Usage: $0 [-o <hexorg>] <paths-to-include>..." 1>&2; exit 1; }
+usage() { echo "Usage: $0 [-a] [-o <hexorg>] <paths-to-include>..." 1>&2; exit 1; }
 
 org='00'
-while getopts ":o:" opt; do
+while getopts ":ao:" opt; do
     case "${opt}" in
+        a)
+            ZASMBIN="${DIR}/emul/zasm/avra"
+            ;;
         o)
             org=${OPTARG}
             ;;
@@ -26,8 +33,6 @@ done
 shift $((OPTIND-1))
 
 # wrapper around ./emul/zasm/zasm that prepares includes CFS prior to call
-DIR=$(dirname "${ABS_PATH}")
-ZASMBIN="${DIR}/emul/zasm/zasm"
 CFSPACK="${DIR}/cfspack/cfspack"
 INCCFS=$(mktemp)