Rename bootloader to bios, add actual bootloader

This commit is contained in:
Byron Lathi
2023-07-31 19:58:32 -07:00
parent 5128fe64b6
commit 18b8ac7ccf
29 changed files with 168 additions and 138 deletions

56
sw/bios/Makefile Normal file
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@@ -0,0 +1,56 @@
CC=../cc65/bin/cl65
CFLAGS=-T -t none -I. --cpu "65C02"
test: CFLAGS=-T -t sim65c02 -I.
LDFLAGS=-C link.ld -m $(NAME).map
SIM=sim65
SIMARGS=-v -c -x 1000000
NAME=bootloader
TEST_BIN=test.bin
BIN=$(NAME).bin
HEX=$(NAME).hex
LISTS=lists
TESTS=tests
SRCS=$(wildcard *.s) $(wildcard *.c)
SRCS+=$(filter-out $(wildcard tests/*), $(wildcard **/*.s)) $(filter-out $(wildcard tests/*) $(wildcard filesystem/*), $(wildcard **/*.c))
OBJS+=$(patsubst %.s,%.o,$(filter %s,$(SRCS)))
OBJS+=$(patsubst %.c,%.o,$(filter %c,$(SRCS)))
TEST_SRCS=$(wildcard $(TESTS)/*.s) $(wildcard $(TESTS)/*.c)
TEST_OBJS+=$(patsubst %.s,%.o,$(filter %s,$(TEST_SRCS)))
TEST_OBJS+=$(patsubst %.c,%.o,$(filter %c,$(TEST_SRCS)))
TEST_OBJS+=$(filter-out boot.o,$(filter-out main.o,$(filter-out vectors.o,$(OBJS))))
all: $(HEX)
test: $(TEST_BIN)
$(SIM) $(SIMARGS) $(TEST_BIN)
$(TEST_BIN): $(OBJS) $(TEST_OBJS)
$(CC) $(CFLAGS) $(TEST_OBJS) -o $@
$(HEX): $(BIN)
objcopy --input-target=binary --output-target=verilog $(BIN) $(HEX)
$(BIN): $(OBJS)
$(CC) $(CFLAGS) $(LDFLAGS) $(OBJS) -o $@
%.o: %.c $(LISTS)
$(CC) $(CFLAGS) -l $(LISTS)/$<.list -c $< -o $@
%.o: %.s $(LISTS)
$(CC) $(CFLAGS) -l $(LISTS)/$<.list -c $< -o $@
$(LISTS):
mkdir -p $(addprefix $(LISTS)/,$(sort $(dir $(SRCS))))
mkdir $(LISTS)/$(sort $(dir $(TEST_SRCS)))
.PHONY: clean
clean:
rm -rf $(OBJS) $(BIN) $(HEX) $(LISTS) $(NAME).map
rm -rf $(TEST_OBJS) $(TEST_BIN)

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@@ -7,6 +7,7 @@
; Checks for a BRK instruction and returns from all valid interrupts.
.import _handle_irq
.import _cputc, _clrscr
.export _irq_int, _nmi_int
@@ -44,5 +45,53 @@ irq: PLA ; Restore accumulator contents
; ---------------------------------------------------------------------------
; BRK detected, stop
break: JMP break ; If BRK is detected, something very bad
; has happened, so stop running
break:
bios_table:
.addr _console_clear
.addr _console_read_char
.addr _console_write_char
_console_clear:
jsr _clrscr
rti
_console_read_char:
; not supported
rti
_console_write_char:
jsr _cputc
rti
; What functions do we need?
; UART
; clear
; write character
; read character
; DISK
; init (or should it just init on boot?)
; read sector into memory
; FS
; init (if disk init succeeds, should it always try?)
; find add
; I think that is all we need for now?
; How do we call the functions?
; we have to call `brk` to trigger the interrupt
; in any of the three registers we can have arguments
; or we could have them pushed to the stack, assuming
; the stack is in the same location
; Or you could pass a pointer which points to an array
; of arguments
; for things like clear, read/write character, and init you don't
; need any arguments.
; jump table index needs to be in x, but also needs to be a multiple
; of 2.

35
sw/bios/link.ld Normal file
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@@ -0,0 +1,35 @@
MEMORY
{
ZP: start = $0, size = $100, type = rw, define = yes;
SDRAM: start = $200, size = $7cf0, type = rw, define = yes;
ROM: start = $F000, size = $1000, file = %O;
}
SEGMENTS {
ZEROPAGE: load = ZP, type = zp, define = yes;
DATA: load = ROM, type = rw, define = yes, run = SDRAM;
BSS: load = SDRAM, type = bss, define = yes;
HEAP: load = SDRAM, type = bss, optional = yes;
STARTUP: load = ROM, type = ro;
ONCE: load = ROM, type = ro, optional = yes;
CODE: load = ROM, type = ro;
RODATA: load = ROM, type = ro;
VECTORS: load = ROM, type = ro, start = $FFFA;
}
FEATURES {
CONDES: segment = STARTUP,
type = constructor,
label = __CONSTRUCTOR_TABLE__,
count = __CONSTRUCTOR_COUNT__;
CONDES: segment = STARTUP,
type = destructor,
label = __DESTRUCTOR_TABLE__,
count = __DESTRUCTOR_COUNT__;
}
SYMBOLS {
# Define the stack size for the application
__STACKSIZE__: value = $0200, type = weak;
__STACKSTART__: type = weak, value = $0800; # 2k stack
}

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@@ -1,39 +1,23 @@
CC=../cc65/bin/cl65
CFLAGS=-T -t none -I. --cpu "65C02"
test: CFLAGS=-T -t sim65c02 -I.
LDFLAGS=-C link.ld -m $(NAME).map
SIM=sim65
SIMARGS=-v -c -x 1000000
NAME=bootloader
TEST_BIN=test.bin
BIN=$(NAME).bin
HEX=$(NAME).hex
LISTS=lists
TESTS=tests
SRCS=$(wildcard *.s) $(wildcard *.c)
SRCS+=$(filter-out $(wildcard tests/*), $(wildcard **/*.s)) $(filter-out $(wildcard tests/*) $(wildcard filesystem/*), $(wildcard **/*.c))
OBJS+=$(patsubst %.s,%.o,$(filter %s,$(SRCS)))
OBJS+=$(patsubst %.c,%.o,$(filter %c,$(SRCS)))
TEST_SRCS=$(wildcard $(TESTS)/*.s) $(wildcard $(TESTS)/*.c)
TEST_OBJS+=$(patsubst %.s,%.o,$(filter %s,$(TEST_SRCS)))
TEST_OBJS+=$(patsubst %.c,%.o,$(filter %c,$(TEST_SRCS)))
TEST_OBJS+=$(filter-out boot.o,$(filter-out main.o,$(filter-out vectors.o,$(OBJS))))
all: $(HEX)
test: $(TEST_BIN)
$(SIM) $(SIMARGS) $(TEST_BIN)
$(TEST_BIN): $(OBJS) $(TEST_OBJS)
$(CC) $(CFLAGS) $(TEST_OBJS) -o $@
$(HEX): $(BIN)
objcopy --input-target=binary --output-target=verilog $(BIN) $(HEX)
objcopy --input-target=binary --output-target=ihex $(BIN) $(HEX)
$(BIN): $(OBJS)
@@ -47,7 +31,6 @@ $(BIN): $(OBJS)
$(LISTS):
mkdir -p $(addprefix $(LISTS)/,$(sort $(dir $(SRCS))))
mkdir $(LISTS)/$(sort $(dir $(TEST_SRCS)))
.PHONY: clean
clean:

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@@ -0,0 +1,23 @@
.segment "BOOTSECTOR"
_start:
jmp _main
.byte "SUPR6502"
_main:
brk
_end:
.res (446+_start-_end)
.res 16
.res 16
.res 16
.res 16
.byte $55
.byte $AA

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@@ -1,35 +1,8 @@
MEMORY
{
ZP: start = $0, size = $100, type = rw, define = yes;
SDRAM: start = $200, size = $7cf0, type = rw, define = yes;
ROM: start = $F000, size = $1000, file = %O;
BOOT: start = $8000, size = $200, file = %O;
}
SEGMENTS {
ZEROPAGE: load = ZP, type = zp, define = yes;
DATA: load = ROM, type = rw, define = yes, run = SDRAM;
BSS: load = SDRAM, type = bss, define = yes;
HEAP: load = SDRAM, type = bss, optional = yes;
STARTUP: load = ROM, type = ro;
ONCE: load = ROM, type = ro, optional = yes;
CODE: load = ROM, type = ro;
RODATA: load = ROM, type = ro;
VECTORS: load = ROM, type = ro, start = $FFFA;
}
FEATURES {
CONDES: segment = STARTUP,
type = constructor,
label = __CONSTRUCTOR_TABLE__,
count = __CONSTRUCTOR_COUNT__;
CONDES: segment = STARTUP,
type = destructor,
label = __DESTRUCTOR_TABLE__,
count = __DESTRUCTOR_COUNT__;
}
SYMBOLS {
# Define the stack size for the application
__STACKSIZE__: value = $0200, type = weak;
__STACKSTART__: type = weak, value = $0800; # 2k stack
BOOTSECTOR: load = BOOT, start = $8000;
}

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@@ -1,89 +0,0 @@
#include <stdio.h>
#include "devices/board_io.h"
#include "devices/uart.h"
#include "devices/interrupt.h"
int main(void)
{
int retval = 0;
int i;
printf("\nStarting tests...\n\n");
printf("Testing hex_set_8...\n");
for (i = 0; i < 3; i++) {
if (hex_set_8(i+1, i)) {
printf("Failed to write to idx %d!\n", i);
retval++;
}
if (*(uint8_t*)0x7ff0+i != i+1) {
printf("Incorrect value at idx %d!\n", i);
retval++;
}
}
if (!hex_set_8(0xab, 3)) {
printf("Writing to idx 3 should fail!\n");
retval++;
}
printf("Done!\n\n");
printf("Testing hex_set_16...\n");
if (hex_set_16(0xabcd)){
printf("Failed to write!\n");
}
if (*(uint16_t*)0x7ff0 != 0xabcd) {
printf("Incorrect value!\n", i);
retval++;
}
printf("Done!\n\n");
printf("Testing hex_set_24...\n");
if (hex_set_24(0xabcdef)){
printf("Failed to write!\n");
}
if (*(uint16_t*)0x7ff0 != 0xcdef && *(uint8_t*)0x7ff2 != 0xab) {
printf("Incorrect value!\n", i);
retval++;
}
printf("Done!\n\n");
printf("Testing hex_enable...\n");
hex_enable(0xa5);
if (*(uint8_t*)0x7ff3 != 0xa5) {
printf("Incorrect value!\n", i);
retval++;
}
printf("Done!\n\n");
printf("Testing uart_txb_block...\n");
*(uint8_t*)0x7ff5 = 0;
uart_txb_block(0xa5);
if (*(uint8_t*)0x7ff4 != 0xa5) {
printf("Incorrect value!\n", i);
retval++;
}
printf("Done!\n\n");
printf("Testing uart_status...\n");
*(uint8_t*)0x7ff5 = 0xa5;
if (uart_status() != 0xa5) {
printf("Incorrect value!\n", i);
retval++;
}
printf("Done!\n\n");
printf("Testing irq_get_status...\n");
*(uint8_t*)0x7fff = 0xa5;
if (irq_get_status() != 0xa5) {
printf("Incorrect value!\n", i);
retval++;
}
printf("Done!\n\n");
return retval != 0;
}