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Kernel minimization (#334)

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* adds patch to remove unused kernel components

* new boards, rebase patches to match

* rename boards for deployment
This commit is contained in:
kaczmarczyck
2021-06-28 14:55:20 +02:00
committed by GitHub
parent 5f20ba544b
commit ce0ee6c054
32 changed files with 1234 additions and 155 deletions
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425
patches/tock/06-firmware-protect.patch Normal file
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@@ -0,0 +1,425 @@
diff --git a/boards/components/src/firmware_protection.rs b/boards/components/src/firmware_protection.rs
new file mode 100644
index 000000000..58695af81
--- /dev/null
+++ b/boards/components/src/firmware_protection.rs
@@ -0,0 +1,70 @@
+//! Component for firmware protection syscall interface.
+//!
+//! This provides one Component, `FirmwareProtectionComponent`, which implements a
+//! userspace syscall interface to enable the code readout protection.
+//!
+//! Usage
+//! -----
+//! ```rust
+//! let crp = components::firmware_protection::FirmwareProtectionComponent::new(
+//! board_kernel,
+//! nrf52840::uicr::Uicr::new()
+//! )
+//! .finalize(
+//! components::firmware_protection_component_helper!(uicr));
+//! ```
+
+use core::mem::MaybeUninit;
+
+use capsules::firmware_protection;
+use kernel::capabilities;
+use kernel::component::Component;
+use kernel::create_capability;
+use kernel::hil;
+use kernel::static_init_half;
+
+// Setup static space for the objects.
+#[macro_export]
+macro_rules! firmware_protection_component_helper {
+ ($C:ty) => {{
+ use capsules::firmware_protection;
+ use core::mem::MaybeUninit;
+ static mut BUF: MaybeUninit<firmware_protection::FirmwareProtection<$C>> =
+ MaybeUninit::uninit();
+ &mut BUF
+ };};
+}
+
+pub struct FirmwareProtectionComponent<C: hil::firmware_protection::FirmwareProtection> {
+ board_kernel: &'static kernel::Kernel,
+ crp: C,
+}
+
+impl<C: 'static + hil::firmware_protection::FirmwareProtection> FirmwareProtectionComponent<C> {
+ pub fn new(board_kernel: &'static kernel::Kernel, crp: C) -> FirmwareProtectionComponent<C> {
+ FirmwareProtectionComponent {
+ board_kernel: board_kernel,
+ crp: crp,
+ }
+ }
+}
+
+impl<C: 'static + hil::firmware_protection::FirmwareProtection> Component
+ for FirmwareProtectionComponent<C>
+{
+ type StaticInput = &'static mut MaybeUninit<firmware_protection::FirmwareProtection<C>>;
+ type Output = &'static firmware_protection::FirmwareProtection<C>;
+
+ unsafe fn finalize(self, static_buffer: Self::StaticInput) -> Self::Output {
+ let grant_cap = create_capability!(capabilities::MemoryAllocationCapability);
+
+ static_init_half!(
+ static_buffer,
+ firmware_protection::FirmwareProtection<C>,
+ firmware_protection::FirmwareProtection::new(
+ self.crp,
+ self.board_kernel.create_grant(&grant_cap),
+ )
+ )
+ }
+}
diff --git a/boards/components/src/lib.rs b/boards/components/src/lib.rs
index 917497af4..520408fcb 100644
--- a/boards/components/src/lib.rs
+++ b/boards/components/src/lib.rs
@@ -9,6 +9,7 @@ pub mod console;
pub mod crc;
pub mod debug_queue;
pub mod debug_writer;
+pub mod firmware_protection;
pub mod ft6x06;
pub mod gpio;
pub mod hd44780;
diff --git a/boards/nordic/nrf52840_dongle_opensk/src/main.rs b/boards/nordic/nrf52840_dongle_opensk/src/main.rs
index f5d29d025..051943867 100644
--- a/boards/nordic/nrf52840_dongle_opensk/src/main.rs
+++ b/boards/nordic/nrf52840_dongle_opensk/src/main.rs
@@ -100,6 +100,7 @@ pub struct Platform {
'static,
nrf52840::usbd::Usbd<'static>,
>,
+ crp: &'static capsules::firmware_protection::FirmwareProtection<nrf52840::uicr::Uicr>,
}
impl kernel::Platform for Platform {
@@ -117,6 +118,7 @@ impl kernel::Platform for Platform {
capsules::analog_comparator::DRIVER_NUM => f(Some(self.analog_comparator)),
nrf52840::nvmc::DRIVER_NUM => f(Some(self.nvmc)),
capsules::usb::usb_ctap::DRIVER_NUM => f(Some(self.usb)),
+ capsules::firmware_protection::DRIVER_NUM => f(Some(self.crp)),
kernel::ipc::DRIVER_NUM => f(Some(&self.ipc)),
_ => f(None),
}
@@ -318,6 +320,14 @@ pub unsafe fn reset_handler() {
)
.finalize(components::usb_ctap_component_buf!(nrf52840::usbd::Usbd));
+ let crp = components::firmware_protection::FirmwareProtectionComponent::new(
+ board_kernel,
+ nrf52840::uicr::Uicr::new(),
+ )
+ .finalize(components::firmware_protection_component_helper!(
+ nrf52840::uicr::Uicr
+ ));
+
nrf52_components::NrfClockComponent::new().finalize(());
let platform = Platform {
@@ -331,6 +341,7 @@ pub unsafe fn reset_handler() {
analog_comparator,
nvmc,
usb,
+ crp,
ipc: kernel::ipc::IPC::new(board_kernel, &memory_allocation_capability),
};
diff --git a/boards/nordic/nrf52840dk_opensk/src/main.rs b/boards/nordic/nrf52840dk_opensk/src/main.rs
index 6a2f8715b..7898562dd 100644
--- a/boards/nordic/nrf52840dk_opensk/src/main.rs
+++ b/boards/nordic/nrf52840dk_opensk/src/main.rs
@@ -163,6 +163,7 @@ pub struct Platform {
'static,
nrf52840::usbd::Usbd<'static>,
>,
+ crp: &'static capsules::firmware_protection::FirmwareProtection<nrf52840::uicr::Uicr>,
}
impl kernel::Platform for Platform {
@@ -180,6 +181,7 @@ impl kernel::Platform for Platform {
capsules::analog_comparator::DRIVER_NUM => f(Some(self.analog_comparator)),
nrf52840::nvmc::DRIVER_NUM => f(Some(self.nvmc)),
capsules::usb::usb_ctap::DRIVER_NUM => f(Some(self.usb)),
+ capsules::firmware_protection::DRIVER_NUM => f(Some(self.crp)),
kernel::ipc::DRIVER_NUM => f(Some(&self.ipc)),
_ => f(None),
}
@@ -403,6 +405,14 @@ pub unsafe fn reset_handler() {
)
.finalize(components::usb_ctap_component_buf!(nrf52840::usbd::Usbd));
+ let crp = components::firmware_protection::FirmwareProtectionComponent::new(
+ board_kernel,
+ nrf52840::uicr::Uicr::new(),
+ )
+ .finalize(components::firmware_protection_component_helper!(
+ nrf52840::uicr::Uicr
+ ));
+
nrf52_components::NrfClockComponent::new().finalize(());
let platform = Platform {
@@ -416,6 +426,7 @@ pub unsafe fn reset_handler() {
analog_comparator,
nvmc,
usb,
+ crp,
ipc: kernel::ipc::IPC::new(board_kernel, &memory_allocation_capability),
};
diff --git a/capsules/src/driver.rs b/capsules/src/driver.rs
index ae458b309..f536dad32 100644
--- a/capsules/src/driver.rs
+++ b/capsules/src/driver.rs
@@ -16,6 +16,7 @@ pub enum NUM {
Adc = 0x00005,
Dac = 0x00006,
AnalogComparator = 0x00007,
+ FirmwareProtection = 0x00008,
// Kernel
Ipc = 0x10000,
diff --git a/capsules/src/firmware_protection.rs b/capsules/src/firmware_protection.rs
new file mode 100644
index 000000000..8cf63d6a4
--- /dev/null
+++ b/capsules/src/firmware_protection.rs
@@ -0,0 +1,85 @@
+//! Provides userspace control of firmware protection on a board.
+//!
+//! This allows an application to enable firware readout protection,
+//! disabling JTAG interface and other ways to read/tamper the firmware.
+//! Of course, outside of a hardware bug, once set, the only way to enable
+//! programming/debugging is by fully erasing the flash.
+//!
+//! Usage
+//! -----
+//!
+//! ```rust
+//! # use kernel::static_init;
+//!
+//! let crp = static_init!(
+//! capsules::firmware_protection::FirmwareProtection,
+//! capsules::firmware_protection::FirmwareProtection::new(
+//! nrf52840::uicr::Uicr,
+//! board_kernel.create_grant(&grant_cap),
+//! );
+//! ```
+//!
+//! Syscall Interface
+//! -----------------
+//!
+//! - Stability: 0 - Draft
+//!
+//! ### Command
+//!
+//! Enable code readout protection on the current board.
+//!
+//! #### `command_num`
+//!
+//! - `0`: Driver check.
+//! - `1`: Get current firmware readout protection (aka CRP) state.
+//! - `2`: Set current firmware readout protection (aka CRP) state.
+//!
+
+use kernel::hil;
+use kernel::{AppId, Callback, Driver, Grant, ReturnCode};
+
+/// Syscall driver number.
+use crate::driver;
+pub const DRIVER_NUM: usize = driver::NUM::FirmwareProtection as usize;
+
+pub struct FirmwareProtection<C: hil::firmware_protection::FirmwareProtection> {
+ crp_unit: C,
+ apps: Grant<Option<Callback>>,
+}
+
+impl<C: hil::firmware_protection::FirmwareProtection> FirmwareProtection<C> {
+ pub fn new(crp_unit: C, apps: Grant<Option<Callback>>) -> Self {
+ Self { crp_unit, apps }
+ }
+}
+
+impl<C: hil::firmware_protection::FirmwareProtection> Driver for FirmwareProtection<C> {
+ ///
+ /// ### Command numbers
+ ///
+ /// * `0`: Returns non-zero to indicate the driver is present.
+ /// * `1`: Gets firmware protection state.
+ /// * `2`: Sets firmware protection state.
+ fn command(&self, command_num: usize, data: usize, _: usize, appid: AppId) -> ReturnCode {
+ match command_num {
+ // return if driver is available
+ 0 => ReturnCode::SUCCESS,
+
+ 1 => self
+ .apps
+ .enter(appid, |_, _| ReturnCode::SuccessWithValue {
+ value: self.crp_unit.get_protection() as usize,
+ })
+ .unwrap_or_else(|err| err.into()),
+
+ // sets firmware protection
+ 2 => self
+ .apps
+ .enter(appid, |_, _| self.crp_unit.set_protection(data.into()))
+ .unwrap_or_else(|err| err.into()),
+
+ // default
+ _ => ReturnCode::ENOSUPPORT,
+ }
+ }
+}
diff --git a/capsules/src/lib.rs b/capsules/src/lib.rs
index e4423fe05..7538aad18 100644
--- a/capsules/src/lib.rs
+++ b/capsules/src/lib.rs
@@ -22,6 +22,7 @@ pub mod crc;
pub mod dac;
pub mod debug_process_restart;
pub mod driver;
+pub mod firmware_protection;
pub mod fm25cl;
pub mod ft6x06;
pub mod fxos8700cq;
diff --git a/chips/nrf52/src/uicr.rs b/chips/nrf52/src/uicr.rs
index 3bb8b5a7d..ea96cb2ae 100644
--- a/chips/nrf52/src/uicr.rs
+++ b/chips/nrf52/src/uicr.rs
@@ -1,13 +1,14 @@
//! User information configuration registers
-
use enum_primitive::cast::FromPrimitive;
+use hil::firmware_protection::ProtectionLevel;
use kernel::common::registers::{register_bitfields, register_structs, ReadWrite};
use kernel::common::StaticRef;
use kernel::hil;
use kernel::ReturnCode;
use crate::gpio::Pin;
+use crate::nvmc::NVMC;
const UICR_BASE: StaticRef<UicrRegisters> =
unsafe { StaticRef::new(0x10001000 as *const UicrRegisters) };
@@ -210,3 +211,49 @@ impl Uicr {
self.registers.approtect.write(ApProtect::PALL::ENABLED);
}
}
+
+impl hil::firmware_protection::FirmwareProtection for Uicr {
+ fn get_protection(&self) -> ProtectionLevel {
+ let ap_protect_state = self.is_ap_protect_enabled();
+ let cpu_debug_state = self
+ .registers
+ .debugctrl
+ .matches_all(DebugControl::CPUNIDEN::ENABLED + DebugControl::CPUFPBEN::ENABLED);
+ match (ap_protect_state, cpu_debug_state) {
+ (false, _) => ProtectionLevel::NoProtection,
+ (true, true) => ProtectionLevel::JtagDisabled,
+ (true, false) => ProtectionLevel::FullyLocked,
+ }
+ }
+
+ fn set_protection(&self, level: ProtectionLevel) -> ReturnCode {
+ let current_level = self.get_protection();
+ if current_level > level || level == ProtectionLevel::Unknown {
+ return ReturnCode::EINVAL;
+ }
+ if current_level == level {
+ return ReturnCode::EALREADY;
+ }
+
+ unsafe { NVMC.configure_writeable() };
+ if level >= ProtectionLevel::JtagDisabled {
+ self.set_ap_protect();
+ }
+
+ if level >= ProtectionLevel::FullyLocked {
+ // Prevent CPU debug and flash patching. Leaving these enabled could
+ // allow to circumvent protection.
+ self.registers
+ .debugctrl
+ .write(DebugControl::CPUNIDEN::DISABLED + DebugControl::CPUFPBEN::DISABLED);
+ // TODO(jmichel): prevent returning into bootloader if present
+ }
+ unsafe { NVMC.configure_readonly() };
+
+ if self.get_protection() == level {
+ ReturnCode::SUCCESS
+ } else {
+ ReturnCode::FAIL
+ }
+ }
+}
diff --git a/kernel/src/hil/firmware_protection.rs b/kernel/src/hil/firmware_protection.rs
new file mode 100644
index 000000000..de0824646
--- /dev/null
+++ b/kernel/src/hil/firmware_protection.rs
@@ -0,0 +1,48 @@
+//! Interface for Firmware Protection, also called Code Readout Protection.
+
+use crate::returncode::ReturnCode;
+
+#[derive(PartialOrd, PartialEq)]
+pub enum ProtectionLevel {
+ /// Unsupported feature
+ Unknown = 0,
+ /// This should be the factory default for the chip.
+ NoProtection = 1,
+ /// At this level, only JTAG/SWD are disabled but other debugging
+ /// features may still be enabled.
+ JtagDisabled = 2,
+ /// This is the maximum level of protection the chip supports.
+ /// At this level, JTAG and all other features are expected to be
+ /// disabled and only a full chip erase may allow to recover from
+ /// that state.
+ FullyLocked = 0xff,
+}
+
+impl From<usize> for ProtectionLevel {
+ fn from(value: usize) -> Self {
+ match value {
+ 1 => ProtectionLevel::NoProtection,
+ 2 => ProtectionLevel::JtagDisabled,
+ 0xff => ProtectionLevel::FullyLocked,
+ _ => ProtectionLevel::Unknown,
+ }
+ }
+}
+
+pub trait FirmwareProtection {
+ /// Gets the current firmware protection level.
+ /// This doesn't fail and always returns a value.
+ fn get_protection(&self) -> ProtectionLevel;
+
+ /// Sets the firmware protection level.
+ /// There are four valid return values:
+ /// - SUCCESS: protection level has been set to `level`
+ /// - FAIL: something went wrong while setting the protection
+ /// level and the effective protection level is not the one
+ /// that was requested.
+ /// - EALREADY: the requested protection level is already the
+ /// level that is set.
+ /// - EINVAL: unsupported protection level or the requested
+ /// protection level is lower than the currently set one.
+ fn set_protection(&self, level: ProtectionLevel) -> ReturnCode;
+}
diff --git a/kernel/src/hil/mod.rs b/kernel/src/hil/mod.rs
index 4f42afa02..83e7702ab 100644
--- a/kernel/src/hil/mod.rs
+++ b/kernel/src/hil/mod.rs
@@ -8,6 +8,7 @@ pub mod dac;
pub mod digest;
pub mod eic;
pub mod entropy;
+pub mod firmware_protection;
pub mod flash;
pub mod gpio;
pub mod gpio_async;