Fix explanation

Author: andre-richter

11_virtual_mem_part1_identity_mapping/README.md

@@ -1018,16 +1018,15 @@ diff -uNr 10_privilege_level/src/main.rs 11_virtual_mem_part1_identity_mapping/s
  #![feature(format_args_nl)]
  #![feature(panic_info_message)]
  #![feature(trait_alias)]
-@@ -132,9 +136,18 @@
+@@ -132,9 +136,17 @@
  /// # Safety
  ///
  /// - Only a single core must be active and running this function.
 -/// - The init calls in this function must appear in the correct order.
 +/// - The init calls in this function must appear in the correct order:
-+///     - Caching must be activated before the device drivers.
-+///       - Without it, any atomic operations, e.g. the yet-to-be-introduced spinlocks in the device
-+///         drivers (which currently employ NullLocks instead of spinlocks), will fail to work on
-+///         the RPi SoCs.
++///     - MMU + Data caching must be activated at the earliest. Without it, any atomic operations,
++///       e.g. the yet-to-be-introduced spinlocks in the device drivers (which currently employ
++///       NullLocks instead of spinlocks), will fail to work (properly) on the RPi SoCs.
  unsafe fn kernel_init() -> ! {
      use driver::interface::DriverManager;
 +    use memory::mmu::interface::MMU;
@@ -1038,7 +1037,7 @@ diff -uNr 10_privilege_level/src/main.rs 11_virtual_mem_part1_identity_mapping/s
 
      for i in bsp::driver::driver_manager().all_device_drivers().iter() {
          if let Err(x) = i.init() {
-@@ -158,6 +171,9 @@
+@@ -158,6 +170,9 @@
 
      info!("Booting on: {}", bsp::board_name());
 
@@ -1048,7 +1047,7 @@ diff -uNr 10_privilege_level/src/main.rs 11_virtual_mem_part1_identity_mapping/s
      let (_, privilege_level) = exception::current_privilege_level();
      info!("Current privilege level: {}", privilege_level);
 
-@@ -181,6 +197,13 @@
+@@ -181,6 +196,13 @@
      info!("Timer test, spinning for 1 second");
      time::time_manager().spin_for(Duration::from_secs(1));
 

11_virtual_mem_part1_identity_mapping/src/main.rs

@@ -137,10 +137,9 @@ mod time;
 ///
 /// - Only a single core must be active and running this function.
 /// - The init calls in this function must appear in the correct order:
-///     - Caching must be activated before the device drivers.
-///       - Without it, any atomic operations, e.g. the yet-to-be-introduced spinlocks in the device
-///         drivers (which currently employ NullLocks instead of spinlocks), will fail to work on
-///         the RPi SoCs.
+///     - MMU + Data caching must be activated at the earliest. Without it, any atomic operations,
+///       e.g. the yet-to-be-introduced spinlocks in the device drivers (which currently employ
+///       NullLocks instead of spinlocks), will fail to work (properly) on the RPi SoCs.
 unsafe fn kernel_init() -> ! {
     use driver::interface::DriverManager;
     use memory::mmu::interface::MMU;

12_exceptions_part1_groundwork/README.md

@@ -953,7 +953,7 @@ diff -uNr 11_virtual_mem_part1_identity_mapping/src/main.rs 12_exceptions_part1_
  #![feature(panic_info_message)]
  #![feature(trait_alias)]
  #![no_main]
-@@ -145,6 +146,8 @@
+@@ -144,6 +145,8 @@
      use driver::interface::DriverManager;
      use memory::mmu::interface::MMU;
 
@@ -962,7 +962,7 @@ diff -uNr 11_virtual_mem_part1_identity_mapping/src/main.rs 12_exceptions_part1_
      if let Err(string) = memory::mmu::mmu().enable_mmu_and_caching() {
          panic!("MMU: {}", string);
      }
-@@ -197,13 +200,28 @@
+@@ -196,13 +199,28 @@
      info!("Timer test, spinning for 1 second");
      time::time_manager().spin_for(Duration::from_secs(1));
 

12_exceptions_part1_groundwork/src/main.rs

@@ -138,10 +138,9 @@ mod time;
 ///
 /// - Only a single core must be active and running this function.
 /// - The init calls in this function must appear in the correct order:
-///     - Caching must be activated before the device drivers.
-///       - Without it, any atomic operations, e.g. the yet-to-be-introduced spinlocks in the device
-///         drivers (which currently employ NullLocks instead of spinlocks), will fail to work on
-///         the RPi SoCs.
+///     - MMU + Data caching must be activated at the earliest. Without it, any atomic operations,
+///       e.g. the yet-to-be-introduced spinlocks in the device drivers (which currently employ
+///       NullLocks instead of spinlocks), will fail to work (properly) on the RPi SoCs.
 unsafe fn kernel_init() -> ! {
     use driver::interface::DriverManager;
     use memory::mmu::interface::MMU;

13_integrated_testing/README.md

@@ -1505,15 +1505,15 @@ diff -uNr 12_exceptions_part1_groundwork/src/main.rs 13_integrated_testing/src/m
 
  /// Early init code.
  ///
-@@ -142,6 +23,7 @@
- ///       - Without it, any atomic operations, e.g. the yet-to-be-introduced spinlocks in the device
- ///         drivers (which currently employ NullLocks instead of spinlocks), will fail to work on
- ///         the RPi SoCs.
+@@ -141,6 +22,7 @@
+ ///     - MMU + Data caching must be activated at the earliest. Without it, any atomic operations,
+ ///       e.g. the yet-to-be-introduced spinlocks in the device drivers (which currently employ
+ ///       NullLocks instead of spinlocks), will fail to work (properly) on the RPi SoCs.
 +#[no_mangle]
  unsafe fn kernel_init() -> ! {
      use driver::interface::DriverManager;
      use memory::mmu::interface::MMU;
-@@ -168,9 +50,7 @@
+@@ -167,9 +49,7 @@
  fn kernel_main() -> ! {
      use bsp::console::console;
      use console::interface::All;
@@ -1523,7 +1523,7 @@ diff -uNr 12_exceptions_part1_groundwork/src/main.rs 13_integrated_testing/src/m
 
      info!("Booting on: {}", bsp::board_name());
 
-@@ -197,31 +77,6 @@
+@@ -196,31 +76,6 @@
          info!("      {}. {}", i + 1, driver.compatible());
      }
 

13_integrated_testing/src/main.rs

@@ -19,10 +19,9 @@ use libkernel::{bsp, console, driver, exception, info, memory, time};
 ///
 /// - Only a single core must be active and running this function.
 /// - The init calls in this function must appear in the correct order:
-///     - Caching must be activated before the device drivers.
-///       - Without it, any atomic operations, e.g. the yet-to-be-introduced spinlocks in the device
-///         drivers (which currently employ NullLocks instead of spinlocks), will fail to work on
-///         the RPi SoCs.
+///     - MMU + Data caching must be activated at the earliest. Without it, any atomic operations,
+///       e.g. the yet-to-be-introduced spinlocks in the device drivers (which currently employ
+///       NullLocks instead of spinlocks), will fail to work (properly) on the RPi SoCs.
 #[no_mangle]
 unsafe fn kernel_init() -> ! {
     use driver::interface::DriverManager;

14_exceptions_part2_peripheral_IRQs/README.md

@@ -857,6 +857,19 @@ diff -uNr 13_integrated_testing/src/_arch/aarch64/exception.rs 14_exceptions_par
 
  #[no_mangle]
 
+diff -uNr 13_integrated_testing/src/_arch/aarch64/memory/mmu.rs 14_exceptions_part2_peripheral_IRQs/src/_arch/aarch64/memory/mmu.rs
+--- 13_integrated_testing/src/_arch/aarch64/memory/mmu.rs
++++ 14_exceptions_part2_peripheral_IRQs/src/_arch/aarch64/memory/mmu.rs
+@@ -149,7 +149,7 @@
+         barrier::isb(barrier::SY);
+
+         // Enable the MMU and turn on data and instruction caching.
+-        SCTLR_EL1.modify(SCTLR_EL1::M::Enable + SCTLR_EL1::C::Cacheable + SCTLR_EL1::I::Cacheable);
++        SCTLR_EL1.modify(SCTLR_EL1::M::Enable);
+
+         // Force MMU init to complete before next instruction.
+         barrier::isb(barrier::SY);
+
 diff -uNr 13_integrated_testing/src/bsp/device_driver/arm/gicv2/gicc.rs 14_exceptions_part2_peripheral_IRQs/src/bsp/device_driver/arm/gicv2/gicc.rs
 --- 13_integrated_testing/src/bsp/device_driver/arm/gicv2/gicc.rs
 +++ 14_exceptions_part2_peripheral_IRQs/src/bsp/device_driver/arm/gicv2/gicc.rs
@@ -2325,18 +2338,16 @@ diff -uNr 13_integrated_testing/src/main.rs 14_exceptions_part2_peripheral_IRQs/
 
  /// Early init code.
  ///
-@@ -21,8 +21,8 @@
+@@ -21,7 +21,7 @@
  /// - The init calls in this function must appear in the correct order:
- ///     - Caching must be activated before the device drivers.
- ///       - Without it, any atomic operations, e.g. the yet-to-be-introduced spinlocks in the device
--///         drivers (which currently employ NullLocks instead of spinlocks), will fail to work on
--///         the RPi SoCs.
-+///         drivers (which currently employ IRQSafeNullLocks instead of spinlocks), will fail to
-+///         work on the RPi SoCs.
+ ///     - MMU + Data caching must be activated at the earliest. Without it, any atomic operations,
+ ///       e.g. the yet-to-be-introduced spinlocks in the device drivers (which currently employ
+-///       NullLocks instead of spinlocks), will fail to work (properly) on the RPi SoCs.
++///       IRQSafeNullLocks instead of spinlocks), will fail to work (properly) on the RPi SoCs.
  #[no_mangle]
  unsafe fn kernel_init() -> ! {
      use driver::interface::DriverManager;
-@@ -42,15 +42,27 @@
+@@ -41,15 +41,27 @@
      bsp::driver::driver_manager().post_device_driver_init();
      // println! is usable from here on.
 
@@ -2366,7 +2377,7 @@ diff -uNr 13_integrated_testing/src/main.rs 14_exceptions_part2_peripheral_IRQs/
 
      info!("Booting on: {}", bsp::board_name());
 
-@@ -77,12 +89,9 @@
+@@ -76,12 +88,9 @@
          info!("      {}. {}", i + 1, driver.compatible());
      }
 

14_exceptions_part2_peripheral_IRQs/src/_arch/aarch64/memory/mmu.rs

@@ -149,7 +149,7 @@ impl memory::mmu::interface::MMU for MemoryManagementUnit {
         barrier::isb(barrier::SY);
 
         // Enable the MMU and turn on data and instruction caching.
-        SCTLR_EL1.modify(SCTLR_EL1::M::Enable + SCTLR_EL1::C::Cacheable + SCTLR_EL1::I::Cacheable);
+        SCTLR_EL1.modify(SCTLR_EL1::M::Enable);
 
         // Force MMU init to complete before next instruction.
         barrier::isb(barrier::SY);

14_exceptions_part2_peripheral_IRQs/src/main.rs

@@ -19,10 +19,9 @@ use libkernel::{bsp, cpu, driver, exception, info, memory, state, time, warn};
 ///
 /// - Only a single core must be active and running this function.
 /// - The init calls in this function must appear in the correct order:
-///     - Caching must be activated before the device drivers.
-///       - Without it, any atomic operations, e.g. the yet-to-be-introduced spinlocks in the device
-///         drivers (which currently employ IRQSafeNullLocks instead of spinlocks), will fail to
-///         work on the RPi SoCs.
+///     - MMU + Data caching must be activated at the earliest. Without it, any atomic operations,
+///       e.g. the yet-to-be-introduced spinlocks in the device drivers (which currently employ
+///       IRQSafeNullLocks instead of spinlocks), will fail to work (properly) on the RPi SoCs.
 #[no_mangle]
 unsafe fn kernel_init() -> ! {
     use driver::interface::DriverManager;

15_virtual_mem_part2_mmio_remap/README.md

@@ -805,6 +805,15 @@ diff -uNr 14_exceptions_part2_peripheral_IRQs/src/_arch/aarch64/memory/mmu.rs 15
 
          self.configure_translation_control();
 
+@@ -149,7 +140,7 @@
+         barrier::isb(barrier::SY);
+
+         // Enable the MMU and turn on data and instruction caching.
+-        SCTLR_EL1.modify(SCTLR_EL1::M::Enable);
++        SCTLR_EL1.modify(SCTLR_EL1::M::Enable + SCTLR_EL1::C::Cacheable + SCTLR_EL1::I::Cacheable);
+
+         // Force MMU init to complete before next instruction.
+         barrier::isb(barrier::SY);
 @@ -162,22 +153,3 @@
          SCTLR_EL1.matches_all(SCTLR_EL1::M::Enable)
      }
@@ -1800,7 +1809,7 @@ diff -uNr 14_exceptions_part2_peripheral_IRQs/src/bsp/raspberrypi/memory.rs 15_v
 +//! | .got                                        |
 +//! |                                             | rx_end_inclusive
 +//! +---------------------------------------------+
-+//! |                                             | rw_start == ro_end
++//! |                                             | rw_start == rx_end
 +//! | .data                                       |
 +//! | .bss                                        |
 +//! |                                             | rw_end_inclusive
@@ -2150,7 +2159,7 @@ diff -uNr 14_exceptions_part2_peripheral_IRQs/src/lib.rs 15_virtual_mem_part2_mm
 diff -uNr 14_exceptions_part2_peripheral_IRQs/src/main.rs 15_virtual_mem_part2_mmio_remap/src/main.rs
 --- 14_exceptions_part2_peripheral_IRQs/src/main.rs
 +++ 15_virtual_mem_part2_mmio_remap/src/main.rs
-@@ -26,21 +26,39 @@
+@@ -25,21 +25,39 @@
  #[no_mangle]
  unsafe fn kernel_init() -> ! {
      use driver::interface::DriverManager;
@@ -2196,7 +2205,7 @@ diff -uNr 14_exceptions_part2_peripheral_IRQs/src/main.rs 15_virtual_mem_part2_m
 
      // Let device drivers register and enable their handlers with the interrupt controller.
      for i in bsp::driver::driver_manager().all_device_drivers() {
-@@ -66,8 +84,8 @@
+@@ -65,8 +83,8 @@
 
      info!("Booting on: {}", bsp::board_name());
 

15_virtual_mem_part2_mmio_remap/src/main.rs

@@ -19,10 +19,9 @@ use libkernel::{bsp, cpu, driver, exception, info, memory, state, time, warn};
 ///
 /// - Only a single core must be active and running this function.
 /// - The init calls in this function must appear in the correct order:
-///     - Caching must be activated before the device drivers.
-///       - Without it, any atomic operations, e.g. the yet-to-be-introduced spinlocks in the device
-///         drivers (which currently employ IRQSafeNullLocks instead of spinlocks), will fail to
-///         work on the RPi SoCs.
+///     - MMU + Data caching must be activated at the earliest. Without it, any atomic operations,
+///       e.g. the yet-to-be-introduced spinlocks in the device drivers (which currently employ
+///       IRQSafeNullLocks instead of spinlocks), will fail to work (properly) on the RPi SoCs.
 #[no_mangle]
 unsafe fn kernel_init() -> ! {
     use driver::interface::DriverManager;