def AddIns(unit: elf_unit.Unit, ins: a64.Ins):
if ins.has_reloc():
sym = unit.FindOrAddSymbol(ins.reloc_symbol, ins.is_local_sym)
unit.AddReloc(ins.reloc_kind, unit.sec_text, sym,
ins.operands[ins.reloc_pos])
ins.clear_reloc()
unit.sec_text.AddData(a64.Assemble(ins).to_bytes(4, byteorder='little'))
def AddStartUpCode(unit: elf_unit.Unit):
"""Add code for `_start` wrapper which calls main(()
When Linux transfers control to a new A32 program is does not follow any calling
convention so we need this shim.
The initial execution env looks like this:
0(sp) argc
8(sp) argv[0] # argv start
16(sp) argv[1]
...
(8*argc)(sp) NULL # argv sentinel
(8*(argc+1))(sp) envp[0] # envp start
(8*(argc+2))(sp) envp[1]
...
NULL # envp sentinel
This feature is needed by CodeGenA64/
"""
unit.FunStart("_start", 16, NOP_BYTES)
for mnemonic, ops in [
("ldr_x_imm", "x0 sp 0"),
("add_x_imm", "x1 sp 8"),
("bl", "expr:call26:main"),
# x0 contains result from main
("movz_x_imm", "x8 0x5d"),
("svc", "0"),
# unreachable
("brk", "1")
]:
HandleOpcode(mnemonic, ops.split(), unit)
unit.FunEnd()
def AddStartUpCode(unit: elf_unit.Unit):
"""Add code for `_start` wrapper which calls main(()
When Linux transfers control to a new A32 program is does not follow any calling
convention so we need this shim.
The initial execution env looks like this:
0(sp) argc
4(sp) argv[0] # argv start
8(sp) argv[1]
...
(4*argc)(sp) NULL # argv sentinel
(4*(argc+1))(sp) envp[0] # envp start
(4*(argc+2))(sp) envp[1]
...
NULL # envp sentinel
This feature is needed by CodeGenA32/
"""
unit.FunStart("_start", 16, NOP_BYTES)
for mnemonic, ops in [("ldr_imm_add", "al r0 sp 0"),
("add_imm", "al r1 sp 4"),
("bl", "al expr:call:main"), ("movw", "al r7 1"),
("svc", "al 0"), ("ud2", "al")]:
HandleOpcode(mnemonic, ops.split(), unit)
unit.FunEnd()
def AddIns(unit: elf_unit.Unit, ins: a32.Ins):
if ins.reloc_kind != elf_enum.RELOC_TYPE_ARM.NONE:
sym = unit.FindOrAddSymbol(ins.reloc_symbol, ins.is_local_sym)
unit.AddReloc(ins.reloc_kind, unit.sec_text, sym,
ins.operands[ins.reloc_pos])
# clear reloc info before proceeding
ins.reloc_kind = elf_enum.RELOC_TYPE_ARM.NONE
ins.operands[ins.reloc_pos] = 0
unit.sec_text.AddData(a32.Assemble(ins).to_bytes(4, byteorder='little'))
def HandleOpcode(mnemonic, token: List[str], unit: elf_unit.Unit):
ins = symbolic.InsFromSymbolized(mnemonic, token)
if ins.reloc_kind != elf_enum.RELOC_TYPE_AARCH64.NONE:
sym = unit.FindOrAddSymbol(ins.reloc_symbol, ins.is_local_sym)
unit.AddReloc(ins.reloc_kind, unit.sec_text, sym,
ins.operands[ins.reloc_pos])
# clear reloc info before proceeding
ins.reloc_kind = elf_enum.RELOC_TYPE_AARCH64.NONE
ins.operands[ins.reloc_pos] = 0
unit.sec_text.AddData(a64.Assemble(ins).to_bytes(4, byteorder='little'))
def AddIns(unit: elf_unit.Unit, ins: x64.Ins):
if ins.has_reloc():
sym = unit.FindOrAddSymbol(ins.reloc_symbol, ins.is_local_sym)
kind = ins.reloc_kind
addend = ins.operands[ins.reloc_pos]
ins.clear_reloc() # we need to clear the reloc info BEFORE assembling
ins_data = bytes(x64.Assemble(
ins)) # note we do not know the exact length because of prefixes
distance_to_ins_end = _RelocFieldOffsetFromEndOfIns(ins.opcode)
if kind in {enum_tab.RELOC_TYPE_X86_64.PC32}:
addend -= distance_to_ins_end
unit.AddReloc(kind, unit.sec_text, sym, addend,
len(ins_data) - distance_to_ins_end)
else:
ins_data = bytes(x64.Assemble(ins))
unit.sec_text.AddData(ins_data)
def AddStartUpCode(unit: elf_unit.Unit):
"""Add code for `_start` wrapper which calls main(()
When Linux transfers control to a new A32 program is does not follow any calling
convention so we need this shim.
The initial execution env looks like this:
0(sp) argc
8(sp) argv[0] # argv start
16(sp) argv[1]
...
(8*argc)(sp) NULL # argv sentinel
(8*(argc+1))(sp) envp[0] # envp start
(8*(argc+2))(sp) envp[1]
...
NULL # envp sentinel
This feature is needed by CodeGenA64/
"""
unit.FunStart("_start", 16, NOP_BYTES)
for mnemonic, ops in [
("mov_64_r_mbis8", "rdi rsp noindex 0 0"), # argc
("lea_64_r_mbis8", "rsi rsp noindex 0 8"), # argv
("lea_64_r_mbis8", "rdx rsp rdi 3 16"), # envp
# default mxcsr is 0x1f80
# description: https://wiki.osdev.org/SSE
# force "rounding down"
("stmxcsr_32_mbis8", "rsp noindex 0 -4"),
("and_32_mbis8_imm32", "rsp noindex 0 -4 0xffff9fff"),
("or_32_mbis8_imm32", "rsp noindex 0 -4 0x2000"),
("ldmxcsr_32_mbis8", "rsp noindex 0 -4"),
("call_32", "expr:pcrel32:main"),
# edi contains result from main
("mov_32_r_imm32", "edi 0x0"),
("mov_64_mr_imm32", "rax 0x3c"),
("syscall", ""),
# unreachable
("int3", "")
]:
HandleOpcode(mnemonic, ops.split(), unit)
unit.FunEnd()