diff options
Diffstat (limited to 'tools/hooks.py')
| -rwxr-xr-x | tools/hooks.py | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/tools/hooks.py b/tools/hooks.py new file mode 100755 index 0000000..13c4e19 --- /dev/null +++ b/tools/hooks.py @@ -0,0 +1,166 @@ +import binascii
+import struct
+
+u32 = struct.Struct('>I')
+
+def make_branch_insn(fromAddr, toAddr, branchType):
+ branchTypes = ['b', 'bl', 'ba', 'bla']
+ if branchType not in branchTypes:
+ raise ValueError, 'invalid branch type: %s' % branchType
+
+ extra = branchTypes.index(branchType)
+
+ distance = toAddr - fromAddr
+ if distance >= 0x2000000 or distance <= -0x2000000:
+ raise ValueError, 'branching too far: %08x to %08x' % (fromAddr, toAddr)
+
+ return (distance & 0x3FFFFFC) | 0x48000000 | extra
+
+
+
+class HookContext(object):
+ """Object which can be used by each hook type to hold data."""
+
+ def __init__(self):
+ self.hooks = []
+
+
+
+class Hook(object):
+ """Generic hook class"""
+
+ has_context = False
+ required_data = []
+
+ def __init__(self, builder, module, data):
+ """Sets up a hook"""
+ self.builder = builder
+ self.module = module
+ self.data = data
+
+ if self.has_context:
+ hookType = type(self)
+ self.context = builder._hook_contexts[hookType]
+ self.context.hooks.append(self)
+
+ # validate the hook's data
+ current_config_name = builder._config_short_name
+
+ for field in self.required_data:
+ field = field.replace('%CONFIG%', current_config_name)
+ if field not in data:
+ raise ValueError, 'hook %s : %s is missing the field %s' % (module.moduleName, data['name'], field)
+
+ def create_patches(self):
+ pass
+
+
+
+class BasicPatchHook(Hook):
+ """Hook that simply patches data to an address"""
+
+ required_data = ['addr_%CONFIG%', 'data']
+
+ def __init__(self, builder, module, data):
+ Hook.__init__(self, builder, module, data)
+
+ def create_patches(self):
+ addr = self.data['addr_%s' % self.builder._config_short_name]
+
+ hex_data = self.data['data']
+
+ whitespace = ' \n\r\t'
+ for char in whitespace:
+ hex_data = hex_data.replace(char, '')
+
+ patch = binascii.unhexlify(hex_data)
+
+ self.builder._add_patch(addr, patch)
+
+
+
+class BranchInsnHook(Hook):
+ """Hook that replaces the instruction at a specific address with a branch"""
+
+ required_data = ['branch_type', 'src_addr_%CONFIG%']
+
+ def __init__(self, builder, module, data):
+ Hook.__init__(self, builder, module, data)
+
+ def create_patches(self):
+ try:
+ target_func = self.data['target_func']
+ except KeyError:
+ target_func = self.data['target_func_%s' % self.builder._config_short_name]
+
+ if isinstance(target_func, str):
+ target_func = self.builder._find_func_by_symbol(target_func)
+ else:
+ # assume it's an address
+ pass
+
+
+ src_addr = self.data['src_addr_%s' % self.builder._config_short_name]
+ branch_insn = make_branch_insn(src_addr, target_func, self.data['branch_type'])
+
+ self.builder._add_patch(src_addr, u32.pack(branch_insn))
+
+
+
+class AddFunctionPointerHook(Hook):
+ """Hook that places a function pointer at an address"""
+
+ required_data = ['src_addr_%CONFIG%']
+
+ def __init__(self, builder, module, data):
+ Hook.__init__(self, builder, module, data)
+
+ def create_patches(self):
+ try:
+ target_func = self.data['target_func']
+ except KeyError:
+ target_func = self.data['target_func_%s' % self.builder._config_short_name]
+
+ if isinstance(target_func, str):
+ target_func = self.builder._find_func_by_symbol(target_func)
+ else:
+ # assume it's an address
+ pass
+
+
+ src_addr = self.data['src_addr_%s' % self.builder._config_short_name]
+
+ self.builder._add_patch(src_addr, u32.pack(target_func))
+
+
+
+class NopInsnHook(Hook):
+ """Hook that NOPs out the instruction(s) at an address"""
+
+ required_data = ['area_%CONFIG%']
+
+ def __init__(self, builder, module, data):
+ Hook.__init__(self, builder, module, data)
+
+ def create_patches(self):
+ area = self.data['area_%s' % self.builder._config_short_name]
+
+ if isinstance(area, list):
+ addr, end = area
+ count = (end + 4 - addr) / 4
+ nop_patch = '\x60\x00\x00\x00' * count
+ else:
+ addr = area
+ nop_patch = '\x60\x00\x00\x00'
+
+ self.builder._add_patch(addr, nop_patch)
+
+
+
+HookTypes = {
+ 'patch': BasicPatchHook,
+ 'branch_insn': BranchInsnHook,
+ 'add_func_pointer': AddFunctionPointerHook,
+ 'nop_insn': NopInsnHook,
+}
+
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