def get_interrupts(self, tree: FdtParser, node: WrappedNode) -> List[KernelInterrupt]:
''' Returns a list of KernelInterrupts that this rule says are used by the kernel for this device. '''
ret = []
interrupts = node.get_interrupts(tree)
for name, rule in self.interrupts.items():
irq_desc = '{} generated from {}'.format(name, node.path)
if type(rule) == dict:
en_macro = rule.get('enable_macro', None)
if rule['index'] >= len(interrupts):
# XXX: skip this rule silently.
continue
defaultIrq = interrupts[rule['index']]
sel_macro = rule.get('sel_macro', None)
falseIrq = interrupts[rule['undef_index']] if 'undef_index' in rule else -1
prio = rule.get('priority', 0)
irq = KernelInterrupt(name, defaultIrq, prio, sel_macro,
falseIrq, en_macro, desc=irq_desc)
elif type(rule) == int:
if rule >= len(interrupts):
# XXX: skip this rule silently.
continue
irq = KernelInterrupt(name, interrupts[rule], desc=irq_desc)
else: # rule == 'boot-cpu'
affinities = node.get_interrupt_affinities()
boot_cpu = tree.get_boot_cpu()
idx = affinities.index(boot_cpu)
irq = KernelInterrupt(name, interrupts[idx])
ret.append(irq)
return ret
def get_matched_compatible(self, device: WrappedNode) -> str:
''' Returns the best matching compatible string for this device '''
if not device.has_prop('compatible'):
raise ValueError(
'Not sure what to do with node {} with no compatible!'.format(device.path))
for compat in device.get_prop('compatible').strings:
if compat in self.rules:
return compat
return None
def _walk(self):
''' walk the underlying fdt, constructing wrapped nodes as we go '''
root = self.fdt.get_rootnode()
self.wrapped_root = WrappedNode(root, None, '/')
# for easier parent lookups
self.by_path = {'/': self.wrapped_root}
for (name, node) in root.walk():
if not isinstance(node, pyfdt.pyfdt.FdtNode):
continue
parent_path = name.rsplit('/', 1)[0]
if parent_path == '':
parent_path = '/'
parent = self.by_path[parent_path]
wrapped = WrappedNode(node, parent, name)
self.by_path[name] = wrapped
if not wrapped.get_phandle():
continue
self.by_phandle[wrapped.get_phandle()] = wrapped
# We only care about interrupt controllers with phandles -
# if an interrupt controller has no phandle, it isn't used anywhere
# and so we can safely ignore it.
if wrapped.has_prop('interrupt-controller') or wrapped.has_prop(
'interrupt-map'):
self.irq_controllers[
wrapped.get_phandle()] = create_irq_controller(
wrapped, self)
def create_irq_controller(node: WrappedNode, tree: 'FdtParser'):
if node.has_prop('interrupt-map'):
# interrupt nexus
return InterruptNexus(node, tree)
elif node.has_prop('compatible'):
# try and find a matching class that will know how to parse it
for compat in node.get_prop('compatible').strings:
if compat in CONTROLLERS:
return CONTROLLERS[compat](node, tree)
# otherwise, just return a dummy irq controller
return IrqController(node, tree)
def get_rule(self, device: WrappedNode) -> DeviceRule:
''' Returns the matching DeviceRule for this device. '''
if not device.has_prop('compatible'):
raise ValueError(
'Not sure what to do with node {} with no compatible!'.format(device.path))
for compat in device.get_prop('compatible').strings:
if compat in self.rules:
return self.rules[compat]
raise ValueError('Failed to match compatibles "{}" for node {}!'.format(
', '.join(device.get_prop('compatible').strings), device.path))
def get_regions(self, node: WrappedNode) -> List[KernelRegionGroup]:
''' Returns a list of KernelRegionGroups that this rule specifies should be mapped into the kernel for this device. '''
ret = []
regions = node.get_regions()
for (i, rule) in self.regions.items():
if i >= len(regions):
# XXX: skip this rule silently
continue
reg = regions[i]
kernel_name = rule['kernel']
user = rule.get('user', False)
macro = rule.get('macro', None)
max_size = 1 << self.config.get_page_bits()
if 'kernel_size' in rule:
max_size = rule['kernel_size']
elif max_size < reg.size:
logging.warning(
"Only mapping {}/{} bytes from node {}, region {}. Set kernel_size in YAML to silence."
.format(max_size, reg.size, node.path, i))
ret.append(
KernelRegionGroup(reg, kernel_name,
self.config.get_page_bits(), max_size, macro,
user))
return ret
def visitor(node: WrappedNode):
if node.has_prop('device_type') and node.get_prop(
'device_type').strings[0] == 'memory':
regions.update(node.get_regions())
class FdtParser:
''' Parse a DTB into a python representation '''
def __init__(self, dtb_file: IO[bytes]):
self.fdt = pyfdt.pyfdt.FdtBlobParse(dtb_file).to_fdt()
self.wrapped_root: WrappedNode
self.by_phandle: Dict[int, WrappedNode] = {}
self.by_path: Dict[str, WrappedNode] = {}
self.irq_controllers: Dict[int, IrqController] = {}
# initialise the "nice" representation of the tree
self._walk()
def _walk(self):
''' walk the underlying fdt, constructing wrapped nodes as we go '''
root = self.fdt.get_rootnode()
self.wrapped_root = WrappedNode(root, None, '/')
# for easier parent lookups
self.by_path = {'/': self.wrapped_root}
for (name, node) in root.walk():
if not isinstance(node, pyfdt.pyfdt.FdtNode):
continue
parent_path = name.rsplit('/', 1)[0]
if parent_path == '':
parent_path = '/'
parent = self.by_path[parent_path]
wrapped = WrappedNode(node, parent, name)
self.by_path[name] = wrapped
if not wrapped.get_phandle():
continue
self.by_phandle[wrapped.get_phandle()] = wrapped
# We only care about interrupt controllers with phandles -
# if an interrupt controller has no phandle, it isn't used anywhere
# and so we can safely ignore it.
if wrapped.has_prop('interrupt-controller') or wrapped.has_prop(
'interrupt-map'):
self.irq_controllers[
wrapped.get_phandle()] = create_irq_controller(
wrapped, self)
def get_phandle(self, phandle: int) -> WrappedNode:
''' Look up a node by phandle '''
return self.by_phandle[phandle]
def get_path(self, path: str) -> WrappedNode:
''' Look up a node by path '''
return self.by_path.get(path, None)
def get_irq_controller(self, phandle: int) -> IrqController:
''' Get an IRQ controller by phandle '''
return self.irq_controllers[phandle]
def lookup_alias(self, alias: str) -> str:
''' Look up a node by its alias '''
alias = alias.split(':')[0]
aliases = self.get_path('/aliases')
if aliases is None or not aliases.has_prop(alias):
raise KeyError('Unmatched alias {}'.format(alias))
prop = aliases.get_prop(alias)
return prop.strings[0]
def get_kernel_devices(self) -> List[WrappedNode]:
''' Returns a list of devices that are used by the kernel '''
chosen = self.get_path('/chosen')
if not chosen.has_prop('seL4,kernel-devices'):
return []
ret = []
paths = chosen.get_prop('seL4,kernel-devices').strings
for path in paths:
if path[0] != '/':
path = self.lookup_alias(path)
ret.append(self.get_path(path))
return ret
def get_boot_cpu(self) -> int:
''' Returns phandle of the cpu node specified by the seL4,boot-cpu property '''
chosen = self.get_path('/chosen')
if not chosen.has_prop('seL4,boot-cpu'):
raise KeyError(
'must specify seL4,boot-cpu in /chosen to get boot cpu')
prop = chosen.get_prop('seL4,boot-cpu')
return prop.words[0]
def visit(self, visitor: Any):
''' Walk the tree, calling the given visitor function on each node '''
self.wrapped_root.visit(visitor)