diff options
| -rw-r--r-- | pokemontools/vba/vba.py | 88 |
1 files changed, 87 insertions, 1 deletions
diff --git a/pokemontools/vba/vba.py b/pokemontools/vba/vba.py index 605a69d..f69595b 100644 --- a/pokemontools/vba/vba.py +++ b/pokemontools/vba/vba.py @@ -187,7 +187,93 @@ class crystal(object): return addresses - def inject_asm(self, asm=[], address=0xdfcf): + def inject_asm_into_rom(self, asm=[], address=0x75 * 0x4000, has_finished_address=0xdb75): + """ + Writes asm to the loaded ROM. Calls the asm. + + :param address: ROM address for where to store the injected asm script. + The default value is an address in pokecrystal that isn't used for + anything. + + :param has_finished_address: address for where to store whether the + script executed or not. This value is restored when the script has been + confirmed to work. It's conceivable that some injected asm might need + to change that address if the asm needs to access the original wram + value itself. + """ + if len(asm) > 0x4000: + raise Exception("too much asm") + + # temporarily use wram + cached_wram_value = self.vba.memory[has_finished_address] + + # set the value at has_finished_address to 0 + reset_wram_mem = list(self.vba.memory) + reset_wram_mem[has_finished_address] = 0 + self.vba.memory = reset_wram_mem + + # set a value to indicate that the script has executed + set_has_finished = [ + # push af + 0xf5, + + # ld a, 1 + 0x3e, 1, + + # ld [has_finished], a + 0xea, has_finished_address & 0xff, has_finished_address >> 8, + + # pop af + 0xf1, + + # ret + 0xc9, + ] + + # TODO: check if asm ends with a byte that causes a return or call or + # other "ender". Raise an exception if it already returns on its own. + + # combine the given asm with the setter bytes + total_asm = asm + set_has_finished + + # get a copy of the current rom + rom = list(self.vba.rom) + + # inject the asm + rom[address : address + len(total_asm)] = total_asm + + # set the rom with the injected asm + self.vba.rom = rom + + # call the injected asm + self.call(calculate_address(address), bank=calculate_bank(address)) + + # make the emulator step forward + self.vba.step(count=20) + + # check if the script has executed (see below) + current_mem = self.vba.memory + + # reset the wram value to its original value + another_mem = list(self.vba.memory) + another_mem[has_finished_address] = cached_wram_value + self.vba.memory = another_mem + + # check if the script has actually executed + # TODO: should this raise an exception if the script didn't finish? + if current_mem[has_finished_address] == 0: + return False + elif current_mem[has_finished_address] == 1: + return True + else: + raise Exception( + "has_finished_address at {has_finished_address} was overwritten with an unexpected value {value}".format( + has_finished_address=hex(has_finished_address), + value=current_mem[has_finished_address], + ) + ) + + def inject_asm_into_wram(self, asm=[], address=0xdfcf): """ Writes asm to memory. Makes the emulator run the asm. |