GameCube .dol disassembler

doldisasm.py

#!/usr/bin/env python
#
# GameCube .dol file disassembler
# Usage: doldisasm.py DOL_FILE > assembly_file.s
#

from capstone import *
from capstone.ppc import *
import sys

r13_addr = None
r2_addr = None

with open(sys.argv[1], 'rb') as dolfile:
    filecontent = bytearray(dolfile.read())

def read_u8(offset):
    return filecontent[offset]

def read_u32(offset):
    return (filecontent[offset + 0] << 24) | (filecontent[offset + 1] << 16) | (filecontent[offset + 2] << 8) | filecontent[offset + 3]

def sign_extend_16(value):
    if value > 0 and (value & 0x8000):
        value -= 0x10000
    return value

def sign_extend_12(value):
    if value > 0 and (value & 0x800):
        value -= 0x1000
    return value

textOffsets = []
textAddresses = []
textSizes = []

dataOffsets = []
dataAddresses = []
dataSizes = []

for i in range(0, 7):
    textOffsets.append(read_u32(0x00 + 4 * i))
    textAddresses.append(read_u32(0x48 + 4 * i))
    textSizes.append(read_u32(0x90 + 4 * i))

for i in range(0, 11):
    dataOffsets.append(read_u32(0x1C + 4 * i))
    dataAddresses.append(read_u32(0x64 + 4 * i))
    dataSizes.append(read_u32(0xAC + 4 * i))

bssAddress = read_u32(0xD8)
bssSize = read_u32(0xDC)
entryPoint = read_u32(0xE0)

print('/*')
print('Code sections:')
for i in range(0, 7):
    if textOffsets[i] != 0 and textAddresses[i] != 0 and textSizes[i] != 0:
        print('\t.text%i:\t0x%08X\t0x%08X\t0x%08X' % (i, textOffsets[i], textAddresses[i], textAddresses[i] + textSizes[i]))
print('Data sections:')
for i in range(0, 11):
    if dataOffsets[i] != 0 and dataAddresses[i] != 0 and dataSizes[i] != 0:
        print('\t.data%i:\t0x%08X\t0x%08X\t0x%08X' % (i, dataOffsets[i], dataAddresses[i], dataAddresses[i] + dataSizes[i]))
print('BSS section:')
print('\t.bss:\t0x%08X\t0x%08X\t0x%08X' % (0, bssAddress, bssAddress + bssSize))
print('Entry Point: 0x%08X' % entryPoint)
print('*/')

labels = set()
labelNames = {}

# Add entry point
labels.add(entryPoint)
labelNames[entryPoint] = '__start'

def addr_to_label(addr):
    if addr in labels:
        if addr in labelNames:
            return labelNames[addr]
        else:
            return "lbl_%08X" % addr
    else:
        return "0x%08X" % addr

def add_label(addr, name):
    labels.add(addr)
    if name != None and not addr in labelNames:
        labelNames[addr] = name

def is_label_candidate(addr):
    for i in range(0, 7):
        if addr >= textAddresses[i] and addr < textAddresses[i] + textSizes[i] and (addr & 3) == 0:
            return True
    for i in range(0, 11):
        if addr >= dataAddresses[i] and addr < dataAddresses[i] + dataSizes[i]:
            return True
    if addr >= bssAddress and addr < bssAddress + bssSize:
        return True
    return False

# TODO: find all of them
loadStoreInsns = {
    PPC_INS_LWZ,
    PPC_INS_LMW,
    PPC_INS_LHA,
    PPC_INS_LHAU,
    PPC_INS_LHZ,
    PPC_INS_LHZU,
    PPC_INS_LBZ,
    PPC_INS_LBZU,
    PPC_INS_LFD,
    PPC_INS_LFDU,
    PPC_INS_LFS,
    PPC_INS_LFSU,
    PPC_INS_STW,
    PPC_INS_STWU,
    PPC_INS_STMW,
    PPC_INS_STH,
    PPC_INS_STHU,
    PPC_INS_STB,
    PPC_INS_STBU,
    PPC_INS_STFS,
    PPC_INS_STFSU,
    PPC_INS_STFD,
    PPC_INS_STDU,
}

# Returns true if the instruction is a load or store with the given register as a base 
def is_load_store_reg_offset(insn, reg):
    return insn.id in loadStoreInsns and (reg == None or insn.operands[1].mem.base == reg)

cs = Cs(CS_ARCH_PPC, CS_MODE_32 | CS_MODE_BIG_ENDIAN)
cs.detail = True
cs.imm_unsigned = False

blacklistedInsns = {
    # Unsupported instructions
    PPC_INS_VMSUMSHM, PPC_INS_VMHADDSHS, PPC_INS_XXSLDWI, PPC_INS_VSEL,
    PPC_INS_XVSUBSP, PPC_INS_XXSEL, PPC_INS_XVMULSP, PPC_INS_XVDIVSP,
    PPC_INS_VADDUHM, PPC_INS_XXPERMDI, PPC_INS_XVMADDASP, PPC_INS_XVMADDMSP,
    PPC_INS_XVCMPGTSP, PPC_INS_XXMRGHD, PPC_INS_XSMSUBMDP, PPC_INS_XSTDIVDP,
    PPC_INS_XVADDSP, PPC_INS_XVCMPEQSP, PPC_INS_XVMSUBASP, PPC_INS_XVCMPGESP,

    # Instructions that Capstone gets wrong
    PPC_INS_MFESR, PPC_INS_MFDEAR, PPC_INS_MTESR, PPC_INS_MTDEAR, PPC_INS_MFICCR, PPC_INS_MFASR
}

# Calls callback for every instruction in the specified code section
def disasm_iter(offset, address, size, callback):
    if size == 0:
        return
    start = address
    end = address + size
    while address < end:
        code = filecontent[offset + (address-start) : offset + size]
        for insn in cs.disasm(code, address):
            address = insn.address
            if insn.id in blacklistedInsns:
                callback(address, offset + address - start, None, insn.bytes)
            else:
                callback(address, offset + address - start, insn, insn.bytes)
            address += 4
        if address < end:
            o = offset + address - start
            callback(address, offset + address - start, None, filecontent[o : o + 4])
            address += 4

lisInsns = {}  # register : insn

splitDataLoads = {}  # address of load insn (both high and low) : data

linkedInsns = {}  # addr of lis insn : ori/addi insn

# Returns true if the instruction writes to the specified register
def reg_modified(insn, reg):
    if insn.op[0].type == PPC_OP_REG and insn.op[0].reg == reg:
        return True
    else:
        return False

# Computes the combined value from a lis, addi/ori instruction pairr
def combine_split_load_value(hiLoadInsn, loLoadInsn):
    assert hiLoadInsn.id == PPC_INS_LIS
    #assert loLoadInsn.id in {PPC_INS_ADDI, PPC_INS_ORI}
    #assert loLoadInsn.operands[1].reg == hiLoadInsn.operands[0].reg
    # hiLoadInsn must be "lis rX, hiPart"
    value = hiLoadInsn.operands[1].imm << 16
    # loLoadInsn must be "addi rY, rX, loPart"
    if loLoadInsn.id == PPC_INS_ORI:
        value |= loLoadInsn.operands[2].imm
    elif loLoadInsn.id == PPC_INS_ADDI:
        value += sign_extend_16(loLoadInsn.operands[2].imm)
    elif is_load_store_reg_offset(loLoadInsn, hiLoadInsn.operands[0].reg):
        value += sign_extend_16(loLoadInsn.operands[1].mem.disp)
    else:
        assert False
    return value

def is_store_insn(insn):
    # TODO: all store instructions
    return insn.id in {PPC_INS_STW}

# Get labels
def get_label_callback(address, offset, insn, bytes):
    global r13_addr
    global r2_addr
    if insn == None:
        return
    #print("%s %s" % (insn.mnemonic, insn.op_str))
    # if branch instruction
    if insn.id in {PPC_INS_B, PPC_INS_BL, PPC_INS_BC, PPC_INS_BDZ, PPC_INS_BDNZ}:
        lisInsns.clear()
        for op in insn.operands:
            if op.type == PPC_OP_IMM:
                #print("label 0x%08X" % op.imm)
                labels.add(op.imm)
                if insn.id == PPC_INS_BL:
                    #labelNames[op.imm] = 'func_%08X' % op.imm
                    add_label(op.imm, 'func_%08X' % op.imm)

    # Detect split load (high part)
    # this is 'lis rX, hipart'
    if insn.id == PPC_INS_LIS:
        # Record instruction that loads into register with 'lis'
        lisInsns[insn.operands[0].reg] = insn
    # Detect split load (low part)
    # this is either 'addi/ori rY, rX, lopart' or 'load/store rY, lopart(rX)'
    elif (insn.id in {PPC_INS_ADDI, PPC_INS_ORI} and insn.operands[1].reg in lisInsns) \
     or  (is_load_store_reg_offset(insn, None) and insn.operands[1].mem.base in lisInsns):
        hiLoadInsn = lisInsns[insn.operands[1].reg]
        # Compute combined value
        value = combine_split_load_value(hiLoadInsn, insn)
        if is_label_candidate(value):
            labels.add(value)
        # Record linked instruction
        linkedInsns[hiLoadInsn.address] = insn
        splitDataLoads[hiLoadInsn.address] = value
        splitDataLoads[insn.address] = value
        lisInsns.pop(insn.operands[1].reg, None)
        # detect r2/r13 initialization
        if insn.id == PPC_INS_ORI and insn.operands[0].reg == insn.operands[1].reg:
            if r2_addr == None and insn.operands[0].reg == PPC_REG_R2:
                r2_addr = value
                #print('# DEBUG: set r2 to 0x%08X' % value)
            elif r13_addr == None and insn.operands[0].reg == PPC_REG_R13:
                r13_addr = value
                #print('# DEBUG: set r13 to 0x%08X' % value)
    # Remove record if register is overwritten
    elif (not is_store_insn(insn)) and len(insn.operands) >= 1 and insn.operands[0].type == PPC_OP_REG:
        lisInsns.pop(insn.operands[0].reg, None)

    # Handle r13 offset values
    if r13_addr != None:
        if insn.id == PPC_INS_ADDI and insn.operands[1].value.reg == PPC_REG_R13:  # r13 offset
            value = r13_addr + sign_extend_16(insn.operands[2].imm)
            if is_label_candidate(value):
                labels.add(value)
                #labelNames[value] = 'r13_%08X' % value
        if is_load_store_reg_offset(insn, PPC_REG_R13):
            value = r13_addr + sign_extend_16(insn.operands[1].mem.disp)
            if is_label_candidate(value):
                labels.add(value)
                #labelNames[value] = 'r13_%08X' % value

    # Handle r2 offset values
    if r2_addr != None:
        if insn.id == PPC_INS_ADDI and insn.operands[1].value.reg == PPC_REG_R2:  # r13 offset
            value = r2_addr + sign_extend_16(insn.operands[2].imm)
            if is_label_candidate(value):
                labels.add(value)
                #labelNames[value] = 'r2_%08X' % value
        if is_load_store_reg_offset(insn, PPC_REG_R2):
            value = r2_addr + sign_extend_16(insn.operands[1].mem.disp)
            if is_label_candidate(value):
                labels.add(value)
                #labelNames[value] = 'r2_%08X' % value

for i in range(0, 7):
    if textSizes[i] != 0:
        disasm_iter(textOffsets[i], textAddresses[i], textSizes[i], get_label_callback)

# Write macros
print('# PowerPC Register Constants')
for i in range(0, 32):
    print(".set r%i, %i" % (i, i))
for i in range(0, 32):
    print(".set f%i, %i" % (i, i))
for i in range(0, 8):
    print(".set qr%i, %i" % (i, i))
if r13_addr != None:
    print('# Small Data Area (read/write) Base')
    print(".set _SDA_BASE_, 0x%08X" % r13_addr)
if r2_addr != None:
    print('# Small Data Area (read only) Base')
    print(".set _SDA2_BASE_, 0x%08X" % r2_addr)
print('')

# Converts the instruction to a string, fixing various issues with Capstone
def insn_to_text(insn, raw):
    # Probably data, not a real instruction
    if insn.id == PPC_INS_BDNZ and (insn.bytes[0] & 1):
        return None
    if insn.id in {PPC_INS_B, PPC_INS_BL, PPC_INS_BDZ, PPC_INS_BDNZ}:
        return "%s %s" % (insn.mnemonic, addr_to_label(insn.operands[0].imm))
    elif insn.id == PPC_INS_BC:
        branchPred = '+' if (insn.bytes[1] & 0x20) else ''
        if insn.operands[0].type == PPC_OP_IMM:
            return "%s%s %s" % (insn.mnemonic, branchPred, addr_to_label(insn.operands[0].imm))
        elif insn.operands[1].type == PPC_OP_IMM:
            return "%s%s %s, %s" % (insn.mnemonic, branchPred, insn.reg_name(insn.operands[0].value.reg), addr_to_label(insn.operands[1].imm))
    # Handle split loads (high part)
    if insn.address in splitDataLoads and insn.id == PPC_INS_LIS:
        loLoadInsn = linkedInsns[insn.address]
        #assert loLoadInsn.id in {PPC_INS_ADDI, PPC_INS_ORI}
        value = splitDataLoads[insn.address]
        suffix = 'h' if loLoadInsn.id == PPC_INS_ORI else 'ha'
        return '%s %s, %s@%s' % (insn.mnemonic, insn.reg_name(insn.operands[0].reg), addr_to_label(value), suffix)
    # Handle split loads (low part)
    elif insn.address in splitDataLoads and insn.id in {PPC_INS_ADDI, PPC_INS_ORI}:
        value = splitDataLoads[insn.address]
        return '%s %s, %s, %s@l' % (insn.mnemonic, insn.reg_name(insn.operands[0].reg), insn.reg_name(insn.operands[1].reg), addr_to_label(value))
    elif insn.address in splitDataLoads and is_load_store_reg_offset(insn, None):
        value = splitDataLoads[insn.address]
        return '%s %s, %s@l(%s)' % (insn.mnemonic, insn.reg_name(insn.operands[0].reg), addr_to_label(value), insn.reg_name(insn.operands[1].mem.base))

    # r13 offset loads
    if r13_addr != None:
        if insn.id == PPC_INS_ADDI and insn.operands[1].reg == PPC_REG_R13:
            value = r13_addr + sign_extend_16(insn.operands[2].imm)
            if value in labels:
                return "%s %s, %s, %s-_SDA_BASE_" % (insn.mnemonic, insn.reg_name(insn.operands[0].reg), insn.reg_name(insn.operands[1].reg), addr_to_label(value))
        if is_load_store_reg_offset(insn, PPC_REG_R13):
            value = r13_addr + sign_extend_16(insn.operands[1].mem.disp)
            if value in labels:
                return "%s %s, %s-_SDA_BASE_(%s)" % (insn.mnemonic, insn.reg_name(insn.operands[0].value.reg), addr_to_label(value), insn.reg_name(insn.operands[1].mem.base))

    # r2 offset loads
    if r2_addr != None:
        if insn.id == PPC_INS_ADDI and insn.operands[1].reg == PPC_REG_R2:
            value = r2_addr + sign_extend_16(insn.operands[2].imm)
            if value in labels:
                return "%s %s, %s, %s-_SDA2_BASE_" % (insn.mnemonic, insn.reg_name(insn.operands[0].reg), insn.reg_name(insn.operands[1].reg), addr_to_label(value))
        if is_load_store_reg_offset(insn, PPC_REG_R2):
            value = r2_addr + sign_extend_16(insn.operands[1].mem.disp)
            if value in labels:
                return "%s %s, %s-_SDA2_BASE_(%s)" % (insn.mnemonic, insn.reg_name(insn.operands[0].value.reg), addr_to_label(value), insn.reg_name(insn.operands[1].mem.base))

    # Sign-extend immediate values because Capstone is an idiot and doesn't do that automatically
    if insn.id in {PPC_INS_ADDI, PPC_INS_ADDIC, PPC_INS_SUBFIC, PPC_INS_MULLI} and (insn.operands[2].imm & 0x8000):
        return "%s %s, %s, %i" % (insn.mnemonic, insn.reg_name(insn.operands[0].reg), insn.reg_name(insn.operands[1].value.reg), insn.operands[2].imm - 0x10000)
    elif (insn.id == PPC_INS_LI or insn.id == PPC_INS_CMPWI) and (insn.operands[1].imm & 0x8000):
        return "%s %s, %i" % (insn.mnemonic, insn.reg_name(insn.operands[0].reg), insn.operands[1].imm - 0x10000)
    # cntlz -> cntlzw
    elif insn.id == PPC_INS_CNTLZW:
        return "cntlzw %s" % insn.op_str
    elif insn.id == PPC_INS_MTICCR:
        return 'mtictc %s' % insn.op_str
    # Dunno why GNU assembler doesn't accept this
    elif insn.id == PPC_INS_LMW and insn.operands[0].reg == PPC_REG_R0:
        return '.4byte 0x%08X  /* illegal %s %s */' % (raw, insn.mnemonic, insn.op_str)
    return '%s %s' % (insn.mnemonic, insn.op_str)

def disasm_ps(inst):
    RA = ((inst >> 16) & 0x1f)
    RB = ((inst >> 11) & 0x1f)
    FA = ((inst >> 16) & 0x1f)
    FB = ((inst >> 11) & 0x1f)
    FC = ((inst >> 6) & 0x1f)
    FD = ((inst >> 21) & 0x1f)
    FS = ((inst >> 21) & 0x1f)
    IX = ((inst >> 7) & 0x7)
    WX = ((inst >> 10) & 0x1)

    opcode = (inst >> 1) & 0x1F
    if opcode == 6:  # doesn't seem to be used
        mnemonic = 'psq_lux' if inst & 0x40 else 'psq_lx'
        return '%s f%i, (r%i + r%i), %i, qr%i' % (mnemonic, FD, RA, RB, WX, IX)
    if opcode == 7:
        mnemonic = 'psq_stux' if inst & 0x40 else 'psq_stx'
        return '%s f%i, r%i, r%i, %i, qr%i' % (mnemonic, FS, RA, RB, WX, IX)
    if opcode == 18:
        return 'ps_div f%i, f%i, f%i' % (FD, FA, FB)
    if opcode == 20:
        return 'ps_sub f%i, f%i, f%i' % (FD, FA, FB)
    if opcode == 21:
        return 'ps_add f%i, f%i, f%i' % (FD, FA, FB)
    if opcode == 23:
        return 'ps_sel f%i, f%i, f%i' % (FD, FA, FC)
    if opcode == 24:
        return 'ps_res f%i, f%i' % (FD, FB)
    if opcode == 25:
        return 'ps_mul f%i, f%i, f%i' % (FD, FA, FC)
    if opcode == 26:
        return 'ps_rsqrte f%i, f%i' % (FD, FB)
    if opcode == 28:
        return 'ps_msub f%i, f%i, f%i, f%i' % (FD, FA, FC, FB)
    if opcode == 29:
        return 'ps_madd f%i, f%i, f%i, f%i' % (FD, FA, FC, FB)
    if opcode == 30:
        return 'ps_nmsub f%i, f%i, f%i, f%i' % (FD, FA, FC, FB)
    if opcode == 31:
        return 'ps_nmadd f%i, f%i, f%i, f%i' % (FD, FA, FC, FB)
    if opcode == 10:
        return 'ps_sum0 f%i, f%i, f%i, f%i' % (FD, FA, FC, FB)
    if opcode == 11:
        return 'ps_sum1 f%i, f%i, f%i, f%i' % (FD, FA, FC, FB)
    if opcode == 12:
        return 'ps_muls0 f%i, f%i, f%i' % (FD, FA, FC)
    if opcode == 13:
        return 'ps_muls1 f%i, f%i, f%i' % (FD, FA, FC)
    if opcode == 14:
        return 'ps_madds0 f%i, f%i, f%i, f%i' % (FD, FA, FC, FB)
    if opcode == 15:
        return 'ps_madds1 f%i, f%i, f%i, f%i' % (FD, FA, FC, FB)

    opcode = (inst >> 1) & 0x3FF
    if opcode == 40:
        return 'ps_neg f%i, f%i' % (FD, FB)
    if opcode == 72:
        return 'ps_mr f%i, f%i' % (FD, FB)
    if opcode == 136:
        return 'ps_nabs f%i, f%i' % (FD, FB)
    if opcode == 264:
        return 'ps_abs f%i, f%i' % (FD, FB)
    if opcode in {0, 32, 64, 96}:
        mnemonics = ['ps_cmpu0', 'ps_cmpo0', 'ps_cmpu1', 'ps_cmpo1']
        mnemonic = mnemonics[(inst >> 6) & 3]
        i = (inst & 0x03800000) >> 23
        return '%s cr%i, f%i, f%i' % (mnemonic, i, FA, FB)
    if opcode == 528:
        return 'ps_merge00 f%i, f%i, f%i' % (FD, FA, FB)
    if opcode == 560:
        return 'ps_merge01 f%i, f%i, f%i' % (FD, FA, FB)
    if opcode == 592:
        return 'ps_merge10 f%i, f%i, f%i' % (FD, FA, FB)
    if opcode == 624:
        return 'ps_merge11 f%i, f%i, f%i' % (FD, FA, FB)
    if opcode == 1014:
        if not (inst & 0x03e00000):
            if (inst & 1) == 0:
                return 'dcbz_l r%i, r%i' % ((inst & 0x001f0000) >> 16, (inst & 0x0000f800) >> 11)
    return None

def disasm_ps_mem(inst, idx):
    RA = ((inst >> 16) & 0x1f)
    RS = ((inst >> 21) & 0x1f)
    I = ((inst >> 12) & 0x7)
    W = ((inst >> 15) & 0x1)
    disp = sign_extend_12(inst & 0xFFF)
    if idx == 56:
        mnemonic = 'psq_l'
    if idx == 57:
        mnemonic = 'psq_lu'
    if idx == 60:
        mnemonic = 'psq_st'
    if idx == 61:
        mnemonic = 'psq_stu'
    return '%s f%i, %i(r%i), %i, qr%i' % (mnemonic, RS, disp, RA, W, I)

def disasm_fcmp(inst):
    crd = (inst & 0x03800000) >> 23
    a = (inst & 0x001f0000) >> 16
    b = (inst & 0x0000f800) >> 11
    return 'fcmpo cr%i, f%i, f%i' % (crd, a, b)

def disasm_mspr(inst, mode):
    if (inst & 1):
        return None
    d = (inst & 0x03e00000) >> 21
    a = (inst & 0x001f0000) >> 16
    b = (inst & 0x0000f800) >>11
    spr = (b << 5) + a
    if mode:
        return 'mtspr 0x%X, r%i' % (spr, d)
    else:
        return 'mfspr r%i, 0x%X' % (d, spr)

def disasm_mcrxr(inst):
    if (inst & 0x007ff801):
        return None
    crd = (inst & 0x03800000) >> 23
    return 'mcrxr cr%i' % crd

# Disassemble code
def disassemble_callback(address, offset, insn, bytes):
    # Output label (if any)
    if address in labels:
        if address in labelNames:
            print("\n.global %s" % addr_to_label(address))
        print("%s:" % addr_to_label(address))
    prefixComment = '/* %08X %08X  %02X %02X %02X %02X */' % (address, offset, bytes[0], bytes[1], bytes[2], bytes[3])
    asm = None
    raw = read_u32(offset)
    if insn != None:
        asm = insn_to_text(insn, raw)
    else:  # Capstone couldn't disassemble it 
        idx = (raw & 0xfc000000) >> 26
        idx2 = (raw & 0x000007fe) >> 1
        # mtspr
        if idx == 31 and idx2 == 467:
            asm = disasm_mspr(raw, 1)
        # mfspr
        elif idx == 31 and idx2 == 339:
            asm = disasm_mspr(raw, 0)
        # mcrxr
        elif idx == 31 and idx2 == 512:
            asm = disasm_mcrxr(raw)
        # fcmpo
        elif idx == 63 and idx2 == 32:
            asm = disasm_fcmp(raw)
        # Paired singles
        elif idx == 4:
            asm = disasm_ps(raw)
        elif idx in {56, 57, 60, 61}:
            asm = disasm_ps_mem(raw, idx)
    if asm == None:
        asm = '.4byte 0x%08X  /* unknown instruction */' % raw
    print('%s\t%s' % (prefixComment, asm))

for i in range(0, 7):
    if textSizes[i] != 0:
        print("\n.section .text%i, \"ax\"  # 0x%08X - 0x%08X" % (i, textAddresses[i], textAddresses[i] + textSizes[i]))
        disasm_iter(textOffsets[i], textAddresses[i], textSizes[i], disassemble_callback)

# Disassemble data
for i in range(0, 11):
    offset = dataOffsets[i]
    address = dataAddresses[i]
    size = dataSizes[i]
    start = address
    end = start + size
    if size == 0:
        continue
    print("\n.section .data%i, \"wa\"  # 0x%08X - 0x%08X" % (i, start, end))
    # Get a sorted list of labels in this data section
    sectionLabels = []
    for l in labels:
        if l >= start and l < end:
            sectionLabels.append(l)
    sectionLabels.sort()
    # Split incbins by labels
    j = 0
    while address < end:
        if j < len(sectionLabels):
            incbinSize = sectionLabels[j] - address
            if incbinSize != 0:
                print("\t.incbin \"baserom.dol\", 0x%X, 0x%X" % (offset, incbinSize))
            l = addr_to_label(sectionLabels[j])
            print(".global %s\n%s:" % (l, l))
            j += 1
        else:
            incbinSize = end - address
            if incbinSize != 0:
                print("\t.incbin \"baserom.dol\", 0x%X, 0x%X" % (offset, incbinSize))
        offset += incbinSize
        address += incbinSize
    # Remove labels to avoid duplicates in case of overlap with other sections
    for l in sectionLabels:
        labels.remove(l)

# Disassemble bss
start = bssAddress
end = bssAddress + bssSize
address = bssAddress
print("\n.section .bss, \"wa\"  # 0x%08X - 0x%08X" % (start, end))
# Get a sorted list of labels in this bss section
sectionLabels = []
for l in labels:
    if l >= start and l < end:
        sectionLabels.append(l)
sectionLabels.sort()
# Split incbins by labels
j = 0
while address < end:
    if j < len(sectionLabels):
        gapSize = sectionLabels[j] - address
        if gapSize != 0:
            print("\t.skip 0x%X" % gapSize)
        l = addr_to_label(sectionLabels[j])
        print(".global %s\n%s:" % (l, l))
        j += 1
    else:
        gapSize = end - address
        if gapSize != 0:
            print("\t.skip 0x%X" % gapSize)
    address += gapSize

# Output linker script
origStdout = sys.stdout
with open('ldscript.ld', 'w') as out:
    sys.stdout = out
    print("ENTRY(__start)")
    if r13_addr != None:
        print("_SDA_BASE_ = 0x%08X;" % r13_addr)
    if r2_addr != None:
        print("_SDA2_BASE_ = 0x%08X;" % r2_addr)
    print("PHDRS\n{")
    for i in range(0, 7):
        if textSizes[i] != 0:
            print("    text%i PT_LOAD;" % i)
    for i in range(0, 11):
        if dataSizes[i] != 0:
            print("    data%i PT_LOAD;" % i)
    print("    bss PT_LOAD;")
    print("}")
    print("SECTIONS\n{")
    for i in range(0, 7):
        if textSizes[i] != 0:
            print("    .text%i 0x%08X : { *(.text%i) } : text%i" % (i, textAddresses[i], i, i))
    for i in range(0, 11):
        if dataSizes[i] != 0:
            print("    .data%i 0x%08X : { *(.data%i) } : data%i" % (i, dataAddresses[i], i, i))
    print("    .bss 0x%08X (NOLOAD) : { *(.bss) } : bss" % bssAddress)
    print("}")
    sys.stdout = origStdout

# Output linker script (Metrowerks)
origStdout = sys.stdout
with open('ldscript.lcf', 'w') as out:
    sys.stdout = out
    if r13_addr != None:
        print("_SDA_BASE_ = 0x%08X;" % r13_addr)
    if r2_addr != None:
        print("_SDA2_BASE_ = 0x%08X;" % r2_addr)
    print("SECTIONS\n{")
    for i in range(0, 7):
        if textSizes[i] != 0:
            print("    .text%i BIND(0x%08X) : { *(.text%i) }" % (i, textAddresses[i], i))
    for i in range(0, 11):
        if dataSizes[i] != 0:
            print("    .data%i BIND(0x%08X) : { *(.data%i) }" % (i, dataAddresses[i], i))
    print("    .bss BIND(0x%08X) : { *(.bss) }" % bssAddress)
    print("}")
    sys.stdout = origStdout

Hi, this appears to be broken on Python 3.8, it gives:

Traceback (most recent call last):
  File "disasm.py", line 274, in <module>
    disasm_iter(textOffsets[i], textAddresses[i], textSizes[i], get_label_callback)
  File "disasm.py", line 150, in disasm_iter
    for insn in cs.disasm(code, address):
  File "/home/jg/.local/lib/python3.8/site-packages/capstone/__init__.py", line 1057, in disasm
    code = ctypes.byref(ctypes.c_char.from_buffer(code))
ValueError: Buffer size too small (0 instead of at least 1 bytes)

Any idea about the issue?

The next release of Capstone v5 will support paired singles so we can remove most of the custom disassembling.