def test_docol_ram(emulator, return_stack, ip, mode, return_stack_depth):
"""Test the docol implementation for RAM mode
On entry:
IP holds the RAM address after the one we've just come from
W holds the address of our NOP instruction
mode holds the mode
On exit:
IP holds the first address of the thread
mode holds the address of NEXT3-ROM-Mode
The return stack holds:
Top: The address of restore-mode (little-endian)
2: The previous mode
3: The old ip (little endian)
"""
# Arrange
return_stack.set_depth_in_bytes(return_stack_depth)
set_IP(ip)
set_mode(mode)
set_W(asm.symbol("forth.NOP"))
# Act
do_test_word(emulator, "forth.NOP")
# Assert
assert end_of_docol == get_IP()
assert asm.symbol("forth.next3.rom-mode") & 0xFF == get_mode()
assert [asm.symbol("forth.RESTORE-MODE"), mode, ip] == [
return_stack.pop_u16(),
return_stack.pop_u8(),
return_stack.pop_u16(),
]
assert len(return_stack) == return_stack_depth
def test_docol_rom(emulator, return_stack, ip, return_stack_depth):
"""Test the docol implementation for RAM mode
On entry:
IP holds the ROM address after the one we've just come from
W holds the address of our NOP instruction
mode holds ROM mode
On exit:
IP holds the first address of the thread
mode holds the address of NEXT3-ROM-Mode
The return stack holds the old ip (little endian)
"""
# Arrange
return_stack.set_depth_in_bytes(return_stack_depth)
set_IP(ip)
set_mode(asm.symbol("forth.next3.rom-mode") & 0xFF)
set_W(nop_start_rom)
# Act
do_test_word(emulator, nop_start_rom)
# Assert
assert end_of_docol == get_IP()
assert asm.symbol("forth.next3.rom-mode") & 0xFF == get_mode()
assert [ip] == [return_stack.pop_u16()]
assert len(return_stack) == return_stack_depth
def test_branch_rom_mode(emulator, address, target):
# Arrange
# Jump target must not intersect with jump
assume(not set(range(address, address + 2))
& set(range(target, target + 3)))
# Jump address cannot be encoded right at the end of a page.
# In practice this is not a problem, it's a two instruction encoding, and we
# already have a requirement that threads can't cross pages.
assume(address & 0xFF != 0xFF)
set_IP(address)
ip_movement = target - address + 3
ROM[target:target + 3] = [
b"\xdc\x42", # st $42,[y, x++]
[0xE0, asm.symbol("forth.move-ip")], # jmp [y,]
b"\xdc\x82", # $82,[y, x++]
]
ROM[address:address + 2] = [
# Encoding for data
[0xFC, target & 0xFF], # bra target
[0x00, ip_movement & 0xFF], # ld ip_movement
]
# Act
do_test_word(emulator,
"forth.internal.rom-mode.BRANCH",
continue_on_reenter=False)
# Assert
assert (target + 3) & 0xFF == get_IP(
) & 0xFF # low-byte equality, because move-ip doesn't handle page crossings
assert 0x8242 == get_W()
def test_next3_ram_rom(emulator, ip):
# Arrange
emulator.next_instruction = "forth.next3.ram-rom-mode"
set_IP(ip)
RAM[ip:ip + 2] = bytearray(struct.pack("<H", WORD_START))
# Act
do_test_word(emulator, continue_on_reenter=False)
# Assert
assert get_W() == WORD_START
assert get_IP() == ip + 2
def test_next3_ram_ram(emulator, ip, target):
# Arrange
# Address IP and target address can't intersect
assume(not set(range(target, target + 2)) & set(range(ip, ip + 2)))
emulator.next_instruction = "forth.next3.ram-ram-mode"
RAM[target:target + 2] = bytearray(struct.pack("<H", WORD_START))
set_IP(ip)
RAM[ip:ip + 2] = bytearray(struct.pack("<H", target))
# Act
do_test_word(emulator, continue_on_reenter=False)
# Assert
assert get_W() == WORD_START
assert get_IP() == ip + 2
def test_next3_rom(emulator):
emulator.next_instruction = "forth.next3.rom-mode"
set_IP(WORD_START)
ROM[WORD_START:WORD_START + 3] = [
b"\xdc\x42", # st $42,[y, x++]
[0xE0, asm.symbol("forth.move-ip")], # jmp [y,]
b"\xdc\x82", # $82,[y, x++]
]
do_test_word(emulator, continue_on_reenter=False)
assert get_W() == 0x8242
assert get_IP() == WORD_START + 3
def test_question_branch_rom_mode(emulator, data_stack, address, target,
data_stack_depth, tos):
# Arrange
# Jump target must not intersect with jump
assume(not set(range(address, address + 5))
& set(range(target, target + 3)))
# We need to not be within the last five bytes of the page,
# as there needs to be an instruction after us to run into if we don't branch.
assume((address & 0xFF) + 5 <= 0xFF)
data_stack.set_depth_in_bytes(data_stack_depth)
data_stack.push_word(tos)
set_IP(address)
ip_movement = target - address + 3
ROM[target:target + 3] = [
b"\xdc\x00", # st $00,[y, x++]
[0xE0, asm.symbol("forth.move-ip")], # jmp [y,]
b"\xdc\x00", # $00,[y, x++]
]
ROM[address:address + 5] = [
# Encoding for data
[0xFC, target & 0xFF], # bra target
[0x00, ip_movement & 0xFF], # ld ip_movement
# Encoding for following word
b"\xdc\xff", # st $ff,[y, x++]
[0xE0, asm.symbol("forth.move-ip")], # jmp [y,]
b"\xdc\xff", # $ff,[y, x++]
]
# Act
do_test_word(emulator,
"forth.internal.rom-mode.?BRANCH",
continue_on_reenter=False)
# Assert
if not tos:
# IP should point after target address
assert (target + 3) & 0xFF == get_IP(
) & 0xFF # low-byte equality, because move-ip doesn't handle page crossings
# Target instruction should be about to run
assert 0x0000 == get_W()
else:
# We run into the encoding of the next instruction, so IP should point after it.
assert (address + 5) & 0xFF == get_IP() & 0xFF
# Next instruction should be about to run
assert 0xFFFF == get_W()
def test_rom_mode_char_literal(emulator, data_stack, data_stack_depth, data):
# Arrange
data_stack.set_depth_in_bytes(data_stack_depth)
set_IP(WORD_START)
ROM[WORD_START : WORD_START + 5] = [
# Encoding for data
[0xDC, data & 0xFF],
[0x10, W], # ld $00,x
# Encoding for next word
b"\xdc\x42", # st $42,[y, x++]
[0xE0, asm.symbol("forth.move-ip")], # jmp [y,]
b"\xdc\x82", # $82,[y, x++]
]
# Act
do_test_word(emulator, "forth.internal.C-LIT", continue_on_reenter=False)
# Assert
assert data == data_stack.pop_i16()
assert data_stack_depth == len(data_stack)
assert WORD_START + 5 == get_IP()
assert 0x8242 == get_W()
def test_docol_ram_ram(emulator, return_stack, ip, target, return_stack_depth):
"""Test jumping from one thread in RAM to another"""
# Arrange
emulator.zero_memory()
return_stack.set_depth_in_bytes(return_stack_depth)
assume(not {ip, ip + 1} & {target, target + 1})
set_IP(ip)
set_mode(asm.symbol("forth.next3.ram-ram-mode") & 0xFF)
RAM[target:target + 2] = [
asm.symbol("forth.DOCOL") & 0xFF,
asm.symbol("forth.DOCOL") >> 8,
]
RAM[ip:ip + 2] = [
target & 0xFF,
target >> 8,
]
# Act
do_test_word(emulator, "forth.next3.ram-ram-mode")
# Assert
assert len(return_stack) == return_stack_depth + 2
assert [ip + 2] == [return_stack.pop_u16()]
assert target + 2 == get_IP()
def _do_test_thread(emulator, label):
set_IP(0x4282)
set_W(symbol(label))
do_test_word(emulator, get_W())
while get_IP() != 0x4282:
do_test_word(emulator, "forth.next3.rom-mode")