Restructure rom image and use dependencies for makefiles

author: Thomas Albers Raviola <thomas@thomaslabs.org> 2025-02-12 01:27:44 +0100
committer: Thomas Albers Raviola <thomas@thomaslabs.org> 2025-02-12 01:27:44 +0100
commit: 779b9834e30de1ba0b4f0755388bebd0c45aa1dc (patch)
tree: 218edb656e329884e4b9cab7e84f4ba4b4af0c4a
parent: 8ac78b9953908d2a4ffece855296fb7597440cce (diff)
15 files changed, 725 insertions, 570 deletions
diff --git a/Makefile b/Makefile
index ea09b19..0040ed2 100644
--- a/Makefile
+++ b/Makefile
@@ -1,66 +1,34 @@
-PROJECT=firmware
+export PROJECT_ROOT=$(abspath .)
 
-AS=sdasz80
-CC=sdcc
-CPP=sdcpp
-
-ASM=crt0.asm\
-	isr.asm\
-	delay.asm
-SRC=font.c\
-	i2c.c\
-	input.c\
-	main.c\
-	tft.c\
-	tty.c\
-	menu.c
-
-INCLUDE=include
 BUILD=build
 
-OBJ=$(ASM:%.asm=$(BUILD)/%.rel)\
-	$(SRC:%.c=$(BUILD)/%.rel)
-
-IHX=$(BUILD)/$(PROJECT).ihx
-TARGET=$(BUILD)/$(PROJECT).hex
+TARGET=$(BUILD)/rom.hex
 BOOTLOADER=$(BUILD)/boot/bootloader.hex
+FIRMWARE=$(BUILD)/firmware.hex
 
-CFLAGS=-mz80 -I$(INCLUDE) --Werror
-LDFLAGS=-mz80 --no-std-crt0\
-		--code-loc 0x0100\
-		--data-loc 0x8010\
-		-Wl-b_ISR_TABLE=0x0070\
-		-Wl-b_GSINIT=0x0080
+CODE_LOC=0x8100
+DATA_LOC=0xC000
+STACK_LOC=0x0000
+GSINIT_LOC=0x8080
 
 ROM_CHIP=AT28C256
 
-all : $(TARGET)
-
-$(OBJ): | $(BUILD)
+DIRS=$(addprefix $(BUILD)/,asm src)
 
-$(BUILD):
-	@mkdir -p $(BUILD)
+ASM=$(wildcard asm/*.asm)
+SRC=$(wildcard src/*.c)
 
-$(BUILD)/%.rel : asm/%.asm
-	@echo '  (AS)' $<
-	@$(CPP) -P -I$(INCLUDE) -DASSEMBLY $< > $(BUILD)/$(notdir $<)
-	@$(AS) -g -o $@ $(BUILD)/$(notdir $<)
-
-$(BUILD)/%.rel : src/%.c
-	@echo '  (CC)' $<
-	@$(CC) $(CFLAGS) -c -o $@ $<
-
-$(IHX) : $(OBJ)
-	@echo '  (LD)' $(OBJ)
-	@$(CC) $(LDFLAGS) -o $@ $(OBJ)
+all : $(TARGET)
 
-$(TARGET) : $(IHX) $(BOOTLOADER)
-	@hex2bin.py -l 32768 $< $@
-	@dd if=$(BOOTLOADER) of=$@ obs=1024 seek=28 conv=notrunc 2>/dev/null
+$(TARGET) : $(BOOTLOADER) $(FIRMWARE)
+	cat $^ > $@
+	cp $(BOOTLOADER) /tmp/rom.hex
+	dd if=$(FIRMWARE) of=/tmp/rom.hex obs=4096 seek=3 conv=notrunc 2>/dev/null
+	mv /tmp/rom.hex $@
 
 .PHONY : $(BOOTLOADER)
 $(BOOTLOADER) :
-	@make -C boot
+	make -C boot
 
 .PHONY : flash
 flash :
@@ -69,3 +37,5 @@ flash :
 .PHONY : clean
 clean :
 	@find $(BUILD) -type f -delete
+
+include include.mk
diff --git a/asm/crt0.asm b/asm/crt0.asm
index fd03997..a53c9e8 100644
--- a/asm/crt0.asm
+++ b/asm/crt0.asm
@@ -1,32 +1,17 @@
 #include <hardware.h>
 
-    .module crt0
-    .globl  _main
+	.module	crt0
+	.globl	_main
 
 	.area	_HEADER (ABS)
-    .org    0x0000
+	.org	0x8000
 start:
-    di
-    xor     a
-    ld      i, a
-    ld      sp, #0x0000
-    ;; Init PIO and check for KEY2
-    ld      a, #PIO_MODE_3
-    out     (PORT_B_CTRL), a
-    ld      a, #0x7F
-    out     (PORT_B_CTRL), a
-    in      a, (PORT_B_DATA)
-    and     #KEY2               ; is KEY2 pressed? If so, start booloader
-    jr      NZ, main
-    ;; Load payload (bootloader)
-    ld      hl, #0x7000         ; src
-    ld      de, #0x8000         ; dest
-    ld      bc, #0x1000         ; size
-    ldir
-    ;; Start bootloader
-    jp      0x8000
+	di
+	ld	a, #0x80
+	ld	i, a
+	ld	sp, #0x0000
 main:
-    call	gsinit
+	call	gsinit
 	call	_main
 1$:
 	halt
@@ -36,44 +21,44 @@ main:
 	.area	_HOME
 	.area	_CODE
 	.area	_INITIALIZER
-	.area   _GSINIT
-	.area   _GSFINAL
+	.area	_GSINIT
+	.area	_GSFINAL
 
 	.area	_DATA
 	.area	_INITIALIZED
 	.area	_BSEG
-	.area   _BSS
-	.area   _HEAP
+	.area	_BSS
+	.area	_HEAP
 
-	.area   _CODE
+	.area	_CODE
 
-	.area   _GSINIT
+	.area	_GSINIT
 gsinit:
 	;; Default-initialized global variables.
-    ld      bc, #l__DATA
-    ld      a, b
-    or      a, c
-    jr      Z, zeroed_data
-    ld      hl, #s__DATA
-    ld      (hl), #0x00
-    dec     bc
-    ld      a, b
-    or      a, c
-    jr      Z, zeroed_data
-    ld      e, l
-    ld      d, h
-    inc     de
-    ldir
+	ld	bc, #l__DATA
+	ld	a, b
+	or	a, c
+	jr	z, zeroed_data
+	ld	hl, #s__DATA
+	ld	(hl), #0x00
+	dec	bc
+	ld	a, b
+	or	a, c
+	jr	z, zeroed_data
+	ld	e, l
+	ld	d, h
+	inc	de
+	ldir
 zeroed_data:
 	;; Explicitly initialized global variables.
 	ld	bc, #l__INITIALIZER
 	ld	a, b
 	or	a, c
-	jr	Z, gsinit_next
+	jr	z, gsinit_next
 	ld	de, #s__INITIALIZED
 	ld	hl, #s__INITIALIZER
 	ldir
 
 gsinit_next:
-	.area   _GSFINAL
+	.area	_GSFINAL
 	ret
diff --git a/boot/Makefile b/boot/Makefile
index 2fff22d..88d3c6e 100644
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -1,50 +1,32 @@
-AS=sdasz80
-CC=sdcc
-CPP=sdcpp
+BUILD=$(PROJECT_ROOT)/build/boot
 
-ASM=crt0.asm
-SRC=crc16.c\
-	bootloader.c
-
-INCLUDE=../include
-BUILD=../build/boot
-
-OBJ=$(ASM:%.asm=$(BUILD)/%.rel)\
-	$(SRC:%.c=$(BUILD)/%.rel)
-
-IHX=$(BUILD)/bootloader.ihx
 TARGET=$(BUILD)/bootloader.hex
+IHX=$(BUILD)/boot.ihx
 
-CFLAGS=-mz80 -I$(INCLUDE) --Werror
-LDFLAGS=-mz80 --no-std-crt0\
-		--code-loc 0x8100\
-		--data-loc 0xC000\
-		--stack-loc 0x0000\
-		-Wl-b_GSINIT=0x8080
+ASM=$(filter-out crt0.asm, $(wildcard *.asm))
+SRC=$(wildcard *.c)
+PAYLOADS=cmd devmode
 
-all : $(TARGET)
-
-$(OBJ): | $(BUILD)
+PAYLOADS_HEX=$(foreach payload,$(PAYLOADS),$(BUILD)/$(payload)/$(payload).hex)
 
-$(BUILD) :
-	@mkdir -p $(BUILD)
+HEX=$(BUILD)/boot.hex $(PAYLOADS_HEX)
 
-$(BUILD)/%.rel : %.asm
-	@echo '  (AS)' $<
-	@$(CPP) -P -I$(INCLUDE) -DASSEMBLY $< > $(BUILD)/$(notdir $<)
-	@$(AS) -g -o $@ $(BUILD)/$(notdir $<)
+CODE_LOC=0x0120
+DATA_LOC=0xC000
+STACK_LOC=0x0000
+GSINIT_LOC=0x0090
 
-$(BUILD)/%.rel : %.c
-	@echo '  (CC)' $<
-	@$(CC) $(CFLAGS) -c -o $@ $<
+all : $(TARGET)
 
-$(IHX) : $(OBJ)
-	@echo '  (LD)' $(OBJ)
-	@$(CC) $(LDFLAGS) -o $@ $(OBJ)
+$(TARGET) : $(HEX)
+	cp $(BUILD)/boot.hex /tmp/bootloader.hex
+	dd if=$(BUILD)/cmd/cmd.hex of=/tmp/bootloader.hex obs=4096 seek=1 conv=notrunc 2>/dev/null
+	dd if=$(BUILD)/cmd/cmd.hex of=/tmp/bootloader.hex obs=4096 seek=2 conv=notrunc 2>/dev/null
+	mv /tmp/bootloader.hex $@
 
-$(TARGET) : $(IHX)
-	@hex2bin.py $< $@
+.PHONY : $(PAYLOADS_HEX)
+$(PAYLOADS_HEX) : $(BUILD)/crt0.rel
+	make -C $(notdir $(basename $@)) CRT0=$<
 
-.PHONY : clean
-clean :
-	@find $(BUILD) -type f -delete
+include $(PROJECT_ROOT)/include.mk
+-include $(BUILD)/crt0.d
diff --git a/boot/boot.asm b/boot/boot.asm
new file mode 100644
index 0000000..b598d6e
--- /dev/null
+++ b/boot/boot.asm
@@ -0,0 +1,128 @@
+#include <hardware.h>
+	.module	boot
+	.globl	_main
+
+	.area	_HEADER (ABS)
+	.org	0x0000
+rst_0:
+	di
+	jr	start
+	.org	0x0008
+rst_1:
+	.org	0x0010
+rst_2:
+	.org	0x0018
+rst_3:
+	.org	0x0020
+rst_4:
+	.org	0x0028
+rst_5:
+	.org	0x0030
+rst_6:
+	.org	0x0038
+rst_7:
+	.org	0x0040
+start:
+	xor	a
+	ld	i, a
+	ld	sp, #0x0000
+	;; Init PIO
+	ld	a, #PIO_MODE_3
+	out	(PORT_B_CTRL), a
+	ld	a, #0x7F
+	out	(PORT_B_CTRL), a
+	;; Check keys
+	in	a, (PORT_B_DATA)
+	bit	KEY2_BIT, a
+	jr	z, development_mode
+	bit	KEY3_BIT, a
+	jr	z, command_line
+	;; No payload selected; try to load os from sd card
+	jr	temporary_payload
+main:
+	call	gsinit
+	call	_main
+1$:
+	halt
+	jr	1$
+
+;;; ROM Payloads
+development_mode:
+	ld	hl, #0x1000	; src
+	ld	de, #0x8000	; dest
+	ld	bc, #0x1000	; size
+	ldir
+	jp	0x8000
+command_line:
+	ld	hl, #0x2000	; src
+	ld	de, #0x8000	; dest
+	ld	bc, #0x1000	; size
+	ldir
+	jp	0x8000
+temporary_payload:
+	ld	hl, #0x3000	; src
+	ld	de, #0x8000	; dest
+	ld	bc, #0x5000	; size
+	ldir
+	jp	0x8000
+
+;;; Interrupt table
+	.org	0x0100
+_ctc0_isr_ptr::
+	.dw	#0
+_ctc1_isr_ptr::
+	.dw	#0
+_ctc2_isr_ptr::
+	.dw	#0
+_ctc3_isr_ptr::
+	.dw	#0
+_port_a_isr_ptr::
+	.dw	#0
+_port_b_isr_ptr::
+	.dw	#0
+_rx_isr_ptr::
+	.dw	#0
+
+	;; Ordering of segments for the linker.
+	.area	_HOME
+	.area	_CODE
+	.area	_INITIALIZER
+	.area	_GSINIT
+	.area	_GSFINAL
+	.area	_DATA
+	.area	_INITIALIZED
+	.area	_BSEG
+	.area	_BSS
+	.area	_HEAP
+	.area	_CODE
+	.area	_GSINIT
+
+gsinit:
+	;; Default-initialized global variables.
+	ld	bc, #l__DATA
+	ld	a, b
+	or	a, c
+	jr	Z, zeroed_data
+	ld	hl, #s__DATA
+	ld	(hl), #0x00
+	dec	bc
+	ld	a, b
+	or	a, c
+	jr	Z, zeroed_data
+	ld	e, l
+	ld	d, h
+	inc		de
+	ldir
+zeroed_data:
+	;; Explicitly initialized global variables.
+	ld	bc, #l__INITIALIZER
+	ld	a, b
+	or	a, c
+	jr	Z, gsinit_next
+	ld	de, #s__INITIALIZED
+	ld	hl, #s__INITIALIZER
+	ldir
+
+gsinit_next:
+	.area	_GSFINAL
+	ret
diff --git a/boot/bootloader.c b/boot/bootloader.c
deleted file mode 100644
index 042414b..0000000
--- a/boot/bootloader.c
+++ /dev/null
@@ -1,376 +0,0 @@
-#include <hardware.h>
-#include <zeta.h>
-#include <fifo.h>
-
-#include <assert.h>
-#include <stddef.h>
-#include <string.h>
-
-#ifdef __GNUC__
-#define PACKED __attribute__((packed))
-#else
-#define PACKED
-#endif
-
-u16
-crc16(const void *buf, size_t len);
-
-enum header_type {
-    CMD_PING,
-    CMD_INFO,
-    CMD_BOOT,
-    CMD_READ,
-    CMD_WRITE,
-    CMD_IO_READ,
-    CMD_IO_WRITE,
-    CMD_ECHO
-};
-
-struct header {
-    u8 type;
-    u8 bank;
-    u16 address;
-    u16 length;
-    u16 checksum;
-} PACKED;
-
-// static_assert(sizeof(struct header) == 8, "struct header is not PACKED");
-
-enum error {
-    ERR_TIMEOUT = -1
-};
-
-#define MAX_PACKET_SIZE 256
-#define TIMEOUT_MS 500
-#define MAX_ATTEMPTS 3
-#define MAX_TRANS_ATTEMPTS 5
-
-u16
-crc16(const void *buf, size_t len);
-
-volatile struct fifo rx_fifo = {0, 0, {0}};
-
-enum ack {
-    ACK = 0x00,
-    NACK = 0xFF
-};
-
-void
-rx_isr(void) __critical __interrupt(0)
-{
-    fifo_push(&rx_fifo, sio_a_data);
-}
-
-static volatile uint32_t millis = 0;
-
-void
-ctc1_isr(void) __critical __interrupt(1)
-{
-    millis += 5;
-}
-
-uint32_t
-clock(void)
-{
-    volatile uint32_t ret;
-    DI;
-    ret = millis;
-    EI;
-    return ret;
-}
-
-void
-putbyte(unsigned char b)
-{
-    unsigned char ctrl = 0;
-
-    sio_a_data = b;
-
-    while (!(ctrl & 0x04)) {
-        sio_a_ctrl = 0;
-        ctrl = sio_a_ctrl;
-    }
-}
-
-static volatile int32_t errno = 0;
-
-u8
-getbyte(void)
-{
-    u8 b;
-    uint32_t ms = clock();
-    errno = 0;
-    while (fifo_empty(&rx_fifo)) {
-        if (clock() - ms > TIMEOUT_MS) {
-            errno = ERR_TIMEOUT;
-            return 0;
-        }
-    }
-    DI;
-    b = fifo_pop(&rx_fifo);
-    EI;
-    return b;
-}
-
-void
-flush(void)
-{
-    DI;
-    fifo_clear(&rx_fifo);
-    EI;
-}
-
-
-// Hamming(7,4) encoding
-u8
-encode(u8 x)
-{
-    u8 y = 0;
-    const u8 c[4] = {0x61, 0x52, 0x34, 0x78};
-
-    for (u8 i = 0; i < 4; ++i)
-        y ^= ((x >> i) & 1) ? c[i] : 0;
-
-    return y;
-}
-
-// Hamming(7,4) decoding
-u8
-decode(u8 x)
-{
-    u8 p = 0;
-    const u8 r[7] = {6, 5, 3, 7, 1, 2, 4};
-
-    for (int i = 0; i < 7; ++i)
-        p ^= ((x >> i) & 1) ? r[i] : 0;
-
-    // Assume simple error, attempt correction
-    if (p) {
-        size_t i = 0;
-
-        for (i = 0; i < LENGTH(r); ++i) {
-            if (r[i] == x)
-                break;
-        }
-
-        x ^= (1 << i);
-    }
-
-    return x & 0x0F;
-}
-
-
-int
-read(void *buf, size_t count)
-{
-    u8 b;
-    u8 *p = buf;
-
-    for (int n = 0; n < count; ++n) {
-        b = decode(getbyte());
-        if (errno)
-            return errno;
-
-        b |= (decode(getbyte()) << 4);
-        if (errno)
-            return errno;
-
-        p[n] = b;
-    }
-
-    return 0;
-}
-
-int
-write(const void *buf, size_t count)
-{
-    const u8 *p = buf;
-
-    for (size_t i = 0; i < count; ++i) {
-        putbyte(encode(p[i] & 0x0F));
-        putbyte(encode((p[i] >> 4) & 0x0F));
-    }
-
-    return 0;
-}
-
-int
-read_header(struct header *header)
-{
-    int err;
-    u8 ack;
-    u16 checksum;
-
-    while (1) {
-        if ((err = read(header, sizeof(*header))))
-            return err;
-
-        checksum = header->checksum;
-        header->checksum = 0;
-
-        if (checksum == crc16(header, sizeof(*header))) {
-            header->checksum = checksum;
-            ack = ACK;
-            write(&ack, sizeof(ack));
-            return 0;
-        } else {
-            ack = NACK;
-            write(&ack, sizeof(ack));
-        }
-    }
-}
-
-int
-read_buf(size_t len, void *buf)
-{
-    int err;
-    u8 ack;
-    u16 checksum;
-
-    for (int i = 0; i < MAX_TRANS_ATTEMPTS; ++i) {
-        // TODO: reduce code?
-        if ((err = read(&checksum, sizeof(checksum)))
-            || (err = read(buf, len)))
-            break;
-
-        if (checksum == crc16(buf, len)) {
-            ack = ACK;
-            write(&ack, sizeof(ack));
-            return 0;
-        } else {
-            ack = NACK;
-            write(&ack, sizeof(ack));
-        }
-    }
-
-    return -1;
-}
-
-int
-write_buf(size_t len, const void *buf)
-{
-    int err;
-    u8 ack = NACK;
-    u16 checksum = crc16(buf, len);
-
-    for (int i = 0; i < MAX_TRANS_ATTEMPTS; ++i){
-        write(&checksum, sizeof(checksum));
-        write(buf, len);
-
-        // If TIMEOUT sending just give up
-        if ((err = read(&ack, sizeof(ack))))
-            return err;
-
-        if (ack == ACK)
-            return 0;
-    }
-
-    return -1;
-}
-
-// TODO: Restart after timeouts
-void
-loop(void)
-{
-    struct header header;
-    u8 buf[MAX_PACKET_SIZE];
-
-    while (1) {
-        if (read_header(&header)) {
-            flush();
-            continue;
-        }
-
-        switch (header.type) {
-        case CMD_BOOT:
-            ((void (*)(void))header.address)();
-            break;
-
-        case CMD_READ:
-            write_buf(header.length, (const void *)header.address);
-            break;
-
-        case CMD_WRITE:
-            if (!read_buf(header.length, buf))
-                memcpy((void *)header.address, buf, header.length);
-            break;
-
-        case CMD_ECHO:
-            if (!read_buf(header.length, buf))
-                write_buf(header.length, buf);
-            break;
-
-        default:
-            break;
-        }
-
-        flush();
-    }
-}
-
-static inline void
-init_ctc(void)
-{
-	ctc_channel_0 = CTC_CTRL(0);
-
-	/* 200Hz clock */
-	ctc_channel_1 = CTC_CTRL(CTC_INT_BIT | CTC_PRESCALER_BIT
-							 | CTC_TIME_CONST_BIT | CTC_RST_BIT);
-	ctc_channel_1 = 0;
-
-	ctc_channel_2 = CTC_CTRL(0);
-	ctc_channel_3 = CTC_CTRL(0);
-
-	// Interrupt table for CTC
-	// Final address is (Ireg << 8) | ctc_isr_ptr | {00/01/10/11} | 0
-	ctc_channel_0 = CTC_INT_VEC(0x10);
-}
-
-static inline void
-init_pio(void)
-{
-	// Disable PIO interrupts
-	port_a_ctrl = PIO_INT_CTRL(0);
-	port_b_ctrl = PIO_INT_CTRL(0);
-}
-
-static inline void
-init_sio(void)
-{
-	static const u8 sio_a_cfg[] = {
-		0b00011000,                      // Reset channel
-		4         ,                      // wr4
-		0b01000100,                      // X16 clock (115200), one stop bit, no parity
-		1         ,                      // wr1
-		SIO_RX_INT_MD0 | SIO_RX_INT_MD1, // interrupt on every Rx, no wait function
-		3         ,                      // wr3
-		0b11000001,                      // enable Rx - 8 bit char
-		5         ,                      // wr5
-		0b01101000                       // enable Tx - 8 bit char
-	};
-
-	static const u8 sio_b_cfg[] = {
-		0b00011000,                     // Reset channel
-		2         ,                     // load interrupt vector
-		0x1C                            // int_table_rx
-	};
-
-    for (u8 i = 0; i < LENGTH(sio_a_cfg); ++i)
-        sio_a_ctrl = sio_a_cfg[i];
-
-    for (u8 i = 0; i < LENGTH(sio_b_cfg); ++i)
-        sio_b_ctrl = sio_b_cfg[i];
-}
-
-void
-main(void)
-{
-	init_ctc();
-	init_pio();
-	init_sio();
-
-	IM(2);
-	EI;
-
-	loop();
-}
diff --git a/boot/cmd/Makefile b/boot/cmd/Makefile
new file mode 100644
index 0000000..5c359e4
--- /dev/null
+++ b/boot/cmd/Makefile
@@ -0,0 +1,12 @@
+BUILD=$(PROJECT_ROOT)/build/boot/cmd
+
+TARGET=$(BUILD)/cmd.hex
+IHX=$(BUILD)/cmd.ihx
+
+ASM=$(wildcard *.asm)
+SRC=$(wildcard *.c)
+
+all : $(TARGET) $(PROJECT_ROOT)/payload.mk
+
+include $(PROJECT_ROOT)/payload.mk
+include $(PROJECT_ROOT)/include.mk
diff --git a/boot/cmd/main.c b/boot/cmd/main.c
new file mode 100644
index 0000000..b363531
--- /dev/null
+++ b/boot/cmd/main.c
@@ -0,0 +1,4 @@
+void
+main(void)
+{
+}
diff --git a/boot/crt0.asm b/boot/crt0.asm
index 09e4166..e7177ed 100644
--- a/boot/crt0.asm
+++ b/boot/crt0.asm
@@ -1,69 +1,67 @@
 #include <hardware.h>
-    .module crt0
-    .globl  _main
+	.module	crt0
+	.globl	_main
 
 	.area	_HEADER (ABS)
-    .org    0x8000
+	.org	0x8000
 start:
-    di
-    ld      a, #0x80
-    ld      i, a
-    ld      sp, #0x0000
-    jr      main
-    .org    0x8010
+	ld	a, #0x80
+	ld	i, a
+	ld	sp, #0x0000
+main:
+	call	gsinit
+	call	_main
+1$:
+	halt
+	jr	1$
+
+;;; Interrupt table
+	.org	0x8020
 _ctc0_isr_ptr::
-    .dw     #0
+	.dw	#0
 _ctc1_isr_ptr::
-    .dw     #_ctc1_isr
+	.dw	#0
 _ctc2_isr_ptr::
-    .dw     #0
+	.dw	#0
 _ctc3_isr_ptr::
-    .dw     #0
+	.dw	#0
 _port_a_isr_ptr::
-    .dw     #0
+	.dw	#0
 _port_b_isr_ptr::
-    .dw     #0
+	.dw	#0
 _rx_isr_ptr::
-    .dw     #_rx_isr
-main:
-    call	gsinit
-	call	_main
-1$:
-	halt
-	jr	1$
+	.dw	#0
 
 	;; Ordering of segments for the linker.
 	.area	_HOME
 	.area	_CODE
 	.area	_INITIALIZER
-	.area   _GSINIT
-	.area   _GSFINAL
-
+	.area	_GSINIT
+	.area	_GSFINAL
 	.area	_DATA
 	.area	_INITIALIZED
 	.area	_BSEG
-	.area   _BSS
-	.area   _HEAP
-
-	.area   _CODE
+	.area	_BSS
+	.area	_HEAP
+	.area	_CODE
+	.area	_GSINIT
 
-	.area   _GSINIT
 gsinit:
 	;; Default-initialized global variables.
-    ld      bc, #l__DATA
-    ld      a, b
-    or      a, c
-    jr      Z, zeroed_data
-    ld      hl, #s__DATA
-    ld      (hl), #0x00
-    dec     bc
-    ld      a, b
-    or      a, c
-    jr      Z, zeroed_data
-    ld      e, l
-    ld      d, h
-    inc     de
-    ldir
+	ld	bc, #l__DATA
+	ld	a, b
+	or	a, c
+	jr	Z, zeroed_data
+	ld	hl, #s__DATA
+	ld	(hl), #0x00
+	dec	bc
+	ld	a, b
+	or	a, c
+	jr	Z, zeroed_data
+	ld	e, l
+	ld	d, h
+	inc		de
+	ldir
 zeroed_data:
 	;; Explicitly initialized global variables.
 	ld	bc, #l__INITIALIZER
@@ -75,5 +73,5 @@ zeroed_data:
 	ldir
 
 gsinit_next:
-	.area   _GSFINAL
+	.area	_GSFINAL
 	ret
diff --git a/boot/devmode/Makefile b/boot/devmode/Makefile
new file mode 100644
index 0000000..24c841a
--- /dev/null
+++ b/boot/devmode/Makefile
@@ -0,0 +1,12 @@
+BUILD=$(PROJECT_ROOT)/build/boot/devmode
+
+TARGET=$(BUILD)/devmode.hex
+IHX=$(BUILD)/devmode.ihx
+
+ASM=$(wildcard *.asm)
+SRC=$(wildcard *.c)
+
+all : $(TARGET)
+
+include $(PROJECT_ROOT)/payload.mk
+include $(PROJECT_ROOT)/include.mk
diff --git a/boot/devmode/bootloader.c b/boot/devmode/bootloader.c
new file mode 100644
index 0000000..dfa9786
--- /dev/null
+++ b/boot/devmode/bootloader.c
@@ -0,0 +1,339 @@
+#include "devmode.h"
+
+#include <hardware.h>
+
+#include <fifo.h>
+
+#include <assert.h>
+#include <stddef.h>
+#include <string.h>
+
+u16
+crc16(const void *buf, size_t len);
+
+volatile struct fifo rx_fifo = {0, 0, {0}};
+
+enum ack {
+    ACK = 0x00,
+    NACK = 0xFF
+};
+
+void
+rx_isr(void) __critical __interrupt(0)
+{
+    fifo_push(&rx_fifo, sio_a_data);
+}
+
+static volatile uint32_t millis = 0;
+
+void
+ctc1_isr(void) __critical __interrupt(1)
+{
+    millis += 5;
+}
+
+uint32_t
+clock(void)
+{
+    volatile uint32_t ret;
+    DI;
+    ret = millis;
+    EI;
+    return ret;
+}
+
+void
+putbyte(unsigned char b)
+{
+    unsigned char ctrl = 0;
+
+    sio_a_data = b;
+
+    while (!(ctrl & 0x04)) {
+	sio_a_ctrl = 0;
+	ctrl = sio_a_ctrl;
+    }
+}
+
+static volatile int32_t errno = 0;
+
+u8
+getbyte(void)
+{
+    u8 b;
+    uint32_t ms = clock();
+    errno = 0;
+    while (fifo_empty(&rx_fifo)) {
+	if (clock() - ms > TIMEOUT_MS) {
+	    errno = ERR_TIMEOUT;
+	    return 0;
+	}
+    }
+    DI;
+    b = fifo_pop(&rx_fifo);
+    EI;
+    return b;
+}
+
+void
+flush(void)
+{
+    DI;
+    fifo_clear(&rx_fifo);
+    EI;
+}
+
+
+// Hamming(7,4) encoding
+u8
+encode(u8 x)
+{
+    u8 y = 0;
+    const u8 c[4] = {0x61, 0x52, 0x34, 0x78};
+
+    for (u8 i = 0; i < 4; ++i)
+	y ^= ((x >> i) & 1) ? c[i] : 0;
+
+    return y;
+}
+
+// Hamming(7,4) decoding
+u8
+decode(u8 x)
+{
+    u8 p = 0;
+    const u8 r[7] = {6, 5, 3, 7, 1, 2, 4};
+
+    for (int i = 0; i < 7; ++i)
+	p ^= ((x >> i) & 1) ? r[i] : 0;
+
+    // Assume simple error, attempt correction
+    if (p) {
+	size_t i = 0;
+
+	for (i = 0; i < LENGTH(r); ++i) {
+	    if (r[i] == x)
+		break;
+	}
+
+	x ^= (1 << i);
+    }
+
+    return x & 0x0F;
+}
+
+
+int
+read(void *buf, size_t count)
+{
+    u8 b;
+    u8 *p = buf;
+
+    for (int n = 0; n < count; ++n) {
+	b = decode(getbyte());
+	if (errno)
+	    return errno;
+
+	b |= (decode(getbyte()) << 4);
+	if (errno)
+	    return errno;
+
+	p[n] = b;
+    }
+
+    return 0;
+}
+
+int
+write(const void *buf, size_t count)
+{
+    const u8 *p = buf;
+
+    for (size_t i = 0; i < count; ++i) {
+	putbyte(encode(p[i] & 0x0F));
+	putbyte(encode((p[i] >> 4) & 0x0F));
+    }
+
+    return 0;
+}
+
+int
+read_header(struct header *header)
+{
+    int err;
+    u8 ack;
+    u16 checksum;
+
+    while (1) {
+	if ((err = read(header, sizeof(*header))))
+	    return err;
+
+	checksum = header->checksum;
+	header->checksum = 0;
+
+	if (checksum == crc16(header, sizeof(*header))) {
+	    header->checksum = checksum;
+	    ack = ACK;
+	    write(&ack, sizeof(ack));
+	    return 0;
+	} else {
+	    ack = NACK;
+	    write(&ack, sizeof(ack));
+	}
+    }
+}
+
+int
+read_buf(size_t len, void *buf)
+{
+    int err;
+    u8 ack;
+    u16 checksum;
+
+    for (int i = 0; i < MAX_TRANS_ATTEMPTS; ++i) {
+	// TODO: reduce code?
+	if ((err = read(&checksum, sizeof(checksum)))
+	    || (err = read(buf, len)))
+	    break;
+
+	if (checksum == crc16(buf, len)) {
+	    ack = ACK;
+	    write(&ack, sizeof(ack));
+	    return 0;
+	} else {
+	    ack = NACK;
+	    write(&ack, sizeof(ack));
+	}
+    }
+
+    return -1;
+}
+
+int
+write_buf(size_t len, const void *buf)
+{
+    int err;
+    u8 ack = NACK;
+    u16 checksum = crc16(buf, len);
+
+    for (int i = 0; i < MAX_TRANS_ATTEMPTS; ++i){
+	write(&checksum, sizeof(checksum));
+	write(buf, len);
+
+	// If TIMEOUT sending just give up
+	if ((err = read(&ack, sizeof(ack))))
+	    return err;
+
+	if (ack == ACK)
+	    return 0;
+    }
+
+    return -1;
+}
+
+// TODO: Restart after timeouts
+void
+loop(void)
+{
+    struct header header;
+    u8 buf[MAX_PACKET_SIZE];
+
+    while (1) {
+	if (read_header(&header)) {
+	    flush();
+	    continue;
+	}
+
+	switch (header.type) {
+	case CMD_BOOT:
+	    ((void (*)(void))header.address)();
+	    break;
+
+	case CMD_READ:
+	    write_buf(header.length, (const void *)header.address);
+	    break;
+
+	case CMD_WRITE:
+	    if (!read_buf(header.length, buf))
+		memcpy((void *)header.address, buf, header.length);
+	    break;
+
+	case CMD_ECHO:
+	    if (!read_buf(header.length, buf))
+		write_buf(header.length, buf);
+	    break;
+
+	default:
+	    break;
+	}
+
+	flush();
+    }
+}
+
+static inline void
+init_ctc(void)
+{
+    ctc_channel_0 = CTC_CTRL(0);
+
+    /* 200Hz clock */
+    ctc_channel_1 = CTC_CTRL(CTC_INT_BIT | CTC_PRESCALER_BIT
+			     | CTC_TIME_CONST_BIT | CTC_RST_BIT);
+    ctc_channel_1 = 0;
+
+    ctc_channel_2 = CTC_CTRL(0);
+    ctc_channel_3 = CTC_CTRL(0);
+
+    // Interrupt table for CTC
+    // Final address is (Ireg << 8) | ctc_isr_ptr | {00/01/10/11} | 0
+    ctc_channel_0 = CTC_INT_VEC(0x10);
+}
+
+static inline void
+init_pio(void)
+{
+    // Disable PIO interrupts
+    port_a_ctrl = PIO_INT_CTRL(0);
+    port_b_ctrl = PIO_INT_CTRL(0);
+}
+
+static inline void
+init_sio(void)
+{
+    static const u8 sio_a_cfg[] = {
+	0b00011000,			 // Reset channel
+	4	  ,			 // wr4
+	0b01000100,			 // X16 clock (115200), one stop bit, no parity
+	1	  ,			 // wr1
+	SIO_RX_INT_MD0 | SIO_RX_INT_MD1, // interrupt on every Rx, no wait function
+	3	  ,			 // wr3
+	0b11000001,			 // enable Rx - 8 bit char
+	5	  ,			 // wr5
+	0b01101000			 // enable Tx - 8 bit char
+    };
+
+    static const u8 sio_b_cfg[] = {
+	0b00011000,			// Reset channel
+	2	  ,			// load interrupt vector
+	0x1C				// int_table_rx
+    };
+
+    for (u8 i = 0; i < LENGTH(sio_a_cfg); ++i)
+	sio_a_ctrl = sio_a_cfg[i];
+
+    for (u8 i = 0; i < LENGTH(sio_b_cfg); ++i)
+	sio_b_ctrl = sio_b_cfg[i];
+}
+
+void
+main(void)
+{
+    init_ctc();
+    init_pio();
+    init_sio();
+
+    IM(2);
+    EI;
+
+    loop();
+}
diff --git a/boot/crc16.c b/boot/devmode/crc16.c
index ec7b015..ac17529 100644
--- a/boot/crc16.c
+++ b/boot/devmode/crc16.c
@@ -6,33 +6,33 @@ static const u16 crc_table[256] = {
     0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
     0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6,
     0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE,
-	0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485,
+    0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485,
     0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D,
-	0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4,
+    0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4,
     0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC,
-	0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823,
+    0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823,
     0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B,
-	0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12,
+    0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12,
     0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A,
-	0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41,
+    0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41,
     0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49,
-	0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70,
+    0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70,
     0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78,
-	0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F,
+    0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F,
     0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067,
-	0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E,
+    0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E,
     0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256,
-	0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D,
+    0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D,
     0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
-	0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C,
+    0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C,
     0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634,
-	0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB,
+    0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB,
     0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3,
-	0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A,
+    0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A,
     0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92,
-	0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9,
+    0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9,
     0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1,
-	0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8,
+    0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8,
     0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0
 };
 
@@ -43,7 +43,7 @@ crc16(const void *buf, size_t len)
 
     u16 crc = 0;
     while (len--)
-        crc = crc_table[(crc >> 8) ^ (*p++)] ^ (crc << 8);
+	crc = crc_table[(crc >> 8) ^ (*p++)] ^ (crc << 8);
 
     return crc;
 }
diff --git a/boot/devmode/devmode.h b/boot/devmode/devmode.h
new file mode 100644
index 0000000..f3322d0
--- /dev/null
+++ b/boot/devmode/devmode.h
@@ -0,0 +1,42 @@
+#ifndef DEVMODE_H
+#define DEVMODE_H
+
+#include <zeta.h>
+
+#ifdef __GNUC__
+#define PACKED __attribute__((packed))
+#else
+#define PACKED
+#endif
+
+enum header_type {
+    CMD_PING,
+    CMD_INFO,
+    CMD_BOOT,
+    CMD_READ,
+    CMD_WRITE,
+    CMD_IO_READ,
+    CMD_IO_WRITE,
+    CMD_ECHO
+};
+
+struct header {
+    u8 type;
+    u8 bank;
+    u16 address;
+    u16 length;
+    u16 checksum;
+} PACKED;
+
+// static_assert(sizeof(struct header) == 8, "struct header is not PACKED");
+
+enum error {
+    ERR_TIMEOUT = -1
+};
+
+#define MAX_PACKET_SIZE 256
+#define TIMEOUT_MS 500
+#define MAX_ATTEMPTS 3
+#define MAX_TRANS_ATTEMPTS 5
+
+#endif // DEVMODE_H
diff --git a/boot/main.c b/boot/main.c
new file mode 100644
index 0000000..5fa3c81
--- /dev/null
+++ b/boot/main.c
@@ -0,0 +1,7 @@
+#include <hardware.h>
+
+void
+main(void)
+{
+	tft_ctrl = 0;
+}
diff --git a/include.mk b/include.mk
new file mode 100644
index 0000000..196f319
--- /dev/null
+++ b/include.mk
@@ -0,0 +1,48 @@
+AS=sdasz80
+CC=sdcc
+CPP=sdcpp
+
+INCLUDE=$(PROJECT_ROOT)/include
+
+DEPFLAGS=-MP -MMD -MF$(basename $@).d -MT$@
+
+ASFLAGS=-g
+ASCPPFLAGS=$(DEPFLAGS) -P -I$(INCLUDE) -DASSEMBLY
+CFLAGS=-mz80 -I$(INCLUDE) --Werror $(patsubst %,-Wp%,$(DEPFLAGS))
+LDFLAGS=-mz80 --no-std-crt0\
+		--code-loc $(CODE_LOC)\
+		--data-loc $(DATA_LOC)\
+		--stack-loc $(STACK_LOC)\
+		-Wl-b_GSINIT=$(GSINIT_LOC)
+
+OBJ=$(patsubst %.asm,$(BUILD)/%.rel,$(ASM))\
+	$(patsubst %.c,$(BUILD)/%.rel,$(SRC))
+DEPS=$(patsubst $(BUILD)/%.rel,$(BUILD)/%.d,$(OBJ))
+
+$(OBJ): | $(BUILD) $(DIRS)
+
+$(BUILD) :
+	@mkdir -p $(BUILD)
+
+$(DIRS) :
+	@mkdir -p $(DIRS)
+
+$(BUILD)/%.rel : %.asm
+	@echo '  (CPP)' $<
+	@$(CPP) $(ASCPPFLAGS) $< > $(basename $@).asm
+	@echo '  (AS)' $<
+	@$(AS) $(ASFLAGS) -o $@ $(basename $@).asm
+
+$(BUILD)/%.rel : %.c
+	@echo '  (CC)' $<
+	@$(CC) $(CFLAGS) -c -o $@ $<
+
+$(BUILD)/%.hex : $(BUILD)/%.ihx
+	@hex2bin.py $< $@
+
+.SECONDARY :
+$(BUILD)/%.ihx : $(CRT0) $(OBJ)
+	@echo '  (LD)' $(OBJ)
+	@$(CC) $(LDFLAGS) -o $@ $+
+
+-include $(DEPS)
diff --git a/payload.mk b/payload.mk
new file mode 100644
index 0000000..8386628
--- /dev/null
+++ b/payload.mk
@@ -0,0 +1,4 @@
+CODE_LOC=0x8100
+DATA_LOC=0xC000
+STACK_LOC=0x0000
+GSINIT_LOC=0x8090
author	Thomas Albers Raviola <thomas@thomaslabs.org>	2025-02-12 01:27:44 +0100
committer	Thomas Albers Raviola <thomas@thomaslabs.org>	2025-02-12 01:27:44 +0100
commit	779b9834e30de1ba0b4f0755388bebd0c45aa1dc (patch)
tree	218edb656e329884e4b9cab7e84f4ba4b4af0c4a
parent	8ac78b9953908d2a4ffece855296fb7597440cce (diff)