Bump compiler version.

We have to remove the `#[naked]` attribute from `_start` for now, since it emits
a warning now when used with non-asm statements in the function body. For now,
just hope for the compiler's mercy to not emit code using the stack pointer
before we've actually set up a stack.

Author: andre-richter

04_zero_overhead_abstraction/README.md

@@ -53,7 +53,7 @@ diff -uNr 03_hacky_hello_world/src/_arch/aarch64/cpu/smp.rs 04_zero_overhead_abs
 diff -uNr 03_hacky_hello_world/src/_arch/aarch64/cpu.rs 04_zero_overhead_abstraction/src/_arch/aarch64/cpu.rs
 --- 03_hacky_hello_world/src/_arch/aarch64/cpu.rs
 +++ 04_zero_overhead_abstraction/src/_arch/aarch64/cpu.rs
-@@ -4,8 +4,34 @@
+@@ -4,8 +4,35 @@
 
  //! Architectural processor code.
 
@@ -72,8 +72,9 @@ diff -uNr 03_hacky_hello_world/src/_arch/aarch64/cpu.rs 04_zero_overhead_abstrac
 +///
 +/// # Safety
 +///
-+/// - Linker script must ensure to place this function at `0x80_000`.
-+#[naked]
++/// - Linker script must ensure to place this function where it is expected by the target machine.
++/// - We have to hope that the compiler omits any stack pointer usage before the stack pointer is
++///   actually set (`SP.set()`).
 +#[no_mangle]
 +pub unsafe fn _start() -> ! {
 +    use crate::runtime_init;
@@ -90,7 +91,7 @@ diff -uNr 03_hacky_hello_world/src/_arch/aarch64/cpu.rs 04_zero_overhead_abstrac
 
  //--------------------------------------------------------------------------------------------------
  // Public Code
-@@ -14,13 +40,7 @@
+@@ -14,13 +41,7 @@
  /// Pause execution on the core.
  #[inline(always)]
  pub fn wait_forever() -> ! {

04_zero_overhead_abstraction/src/_arch/aarch64/cpu.rs

@@ -17,8 +17,9 @@ use cortex_a::{asm, regs::*};
 ///
 /// # Safety
 ///
-/// - Linker script must ensure to place this function at `0x80_000`.
-#[naked]
+/// - Linker script must ensure to place this function where it is expected by the target machine.
+/// - We have to hope that the compiler omits any stack pointer usage before the stack pointer is
+///   actually set (`SP.set()`).
 #[no_mangle]
 pub unsafe fn _start() -> ! {
     use crate::runtime_init;

05_safe_globals/src/_arch/aarch64/cpu.rs

@@ -17,8 +17,9 @@ use cortex_a::{asm, regs::*};
 ///
 /// # Safety
 ///
-/// - Linker script must ensure to place this function at `0x80_000`.
-#[naked]
+/// - Linker script must ensure to place this function where it is expected by the target machine.
+/// - We have to hope that the compiler omits any stack pointer usage before the stack pointer is
+///   actually set (`SP.set()`).
 #[no_mangle]
 pub unsafe fn _start() -> ! {
     use crate::runtime_init;

06_drivers_gpio_uart/README.md

@@ -183,7 +183,7 @@ diff -uNr 05_safe_globals/Makefile 06_drivers_gpio_uart/Makefile
 diff -uNr 05_safe_globals/src/_arch/aarch64/cpu.rs 06_drivers_gpio_uart/src/_arch/aarch64/cpu.rs
 --- 05_safe_globals/src/_arch/aarch64/cpu.rs
 +++ 06_drivers_gpio_uart/src/_arch/aarch64/cpu.rs
-@@ -37,6 +37,17 @@
+@@ -38,6 +38,17 @@
  // Public Code
  //--------------------------------------------------------------------------------------------------
 

06_drivers_gpio_uart/src/_arch/aarch64/cpu.rs

@@ -17,8 +17,9 @@ use cortex_a::{asm, regs::*};
 ///
 /// # Safety
 ///
-/// - Linker script must ensure to place this function at `0x80_000`.
-#[naked]
+/// - Linker script must ensure to place this function where it is expected by the target machine.
+/// - We have to hope that the compiler omits any stack pointer usage before the stack pointer is
+///   actually set (`SP.set()`).
 #[no_mangle]
 pub unsafe fn _start() -> ! {
     use crate::runtime_init;

07_uart_chainloader/README.md

@@ -179,8 +179,8 @@ diff -uNr 06_drivers_gpio_uart/Makefile 07_uart_chainloader/Makefile
 diff -uNr 06_drivers_gpio_uart/src/_arch/aarch64/cpu.rs 07_uart_chainloader/src/_arch/aarch64/cpu.rs
 --- 06_drivers_gpio_uart/src/_arch/aarch64/cpu.rs
 +++ 07_uart_chainloader/src/_arch/aarch64/cpu.rs
-@@ -21,12 +21,12 @@
- #[naked]
+@@ -22,12 +22,12 @@
+ ///   actually set (`SP.set()`).
  #[no_mangle]
  pub unsafe fn _start() -> ! {
 -    use crate::runtime_init;
@@ -194,7 +194,7 @@ diff -uNr 06_drivers_gpio_uart/src/_arch/aarch64/cpu.rs 07_uart_chainloader/src/
      } else {
          // If not core0, infinitely wait for events.
          wait_forever()
-@@ -55,3 +55,19 @@
+@@ -56,3 +56,19 @@
          asm::wfe()
      }
  }

07_uart_chainloader/src/_arch/aarch64/cpu.rs

@@ -17,8 +17,9 @@ use cortex_a::{asm, regs::*};
 ///
 /// # Safety
 ///
-/// - Linker script must ensure to place this function at `0x80_000`.
-#[naked]
+/// - Linker script must ensure to place this function where it is expected by the target machine.
+/// - We have to hope that the compiler omits any stack pointer usage before the stack pointer is
+///   actually set (`SP.set()`).
 #[no_mangle]
 pub unsafe fn _start() -> ! {
     use crate::relocate;

08_timestamps/README.md

@@ -115,8 +115,8 @@ diff -uNr 07_uart_chainloader/Makefile 08_timestamps/Makefile
 diff -uNr 07_uart_chainloader/src/_arch/aarch64/cpu.rs 08_timestamps/src/_arch/aarch64/cpu.rs
 --- 07_uart_chainloader/src/_arch/aarch64/cpu.rs
 +++ 08_timestamps/src/_arch/aarch64/cpu.rs
-@@ -21,12 +21,12 @@
- #[naked]
+@@ -22,12 +22,12 @@
+ ///   actually set (`SP.set()`).
  #[no_mangle]
  pub unsafe fn _start() -> ! {
 -    use crate::relocate;
@@ -130,7 +130,7 @@ diff -uNr 07_uart_chainloader/src/_arch/aarch64/cpu.rs 08_timestamps/src/_arch/a
      } else {
          // If not core0, infinitely wait for events.
          wait_forever()
-@@ -39,15 +39,6 @@
+@@ -40,15 +40,6 @@
 
  pub use asm::nop;
 
@@ -146,7 +146,7 @@ diff -uNr 07_uart_chainloader/src/_arch/aarch64/cpu.rs 08_timestamps/src/_arch/a
  /// Pause execution on the core.
  #[inline(always)]
  pub fn wait_forever() -> ! {
-@@ -55,19 +46,3 @@
+@@ -56,19 +47,3 @@
          asm::wfe()
      }
  }

08_timestamps/src/_arch/aarch64/cpu.rs

@@ -17,8 +17,9 @@ use cortex_a::{asm, regs::*};
 ///
 /// # Safety
 ///
-/// - Linker script must ensure to place this function at `0x80_000`.
-#[naked]
+/// - Linker script must ensure to place this function where it is expected by the target machine.
+/// - We have to hope that the compiler omits any stack pointer usage before the stack pointer is
+///   actually set (`SP.set()`).
 #[no_mangle]
 pub unsafe fn _start() -> ! {
     use crate::runtime_init;

09_hw_debug_JTAG/src/_arch/aarch64/cpu.rs

@@ -17,8 +17,9 @@ use cortex_a::{asm, regs::*};
 ///
 /// # Safety
 ///
-/// - Linker script must ensure to place this function at `0x80_000`.
-#[naked]
+/// - Linker script must ensure to place this function where it is expected by the target machine.
+/// - We have to hope that the compiler omits any stack pointer usage before the stack pointer is
+///   actually set (`SP.set()`).
 #[no_mangle]
 pub unsafe fn _start() -> ! {
     use crate::runtime_init;

10_privilege_level/README.md

@@ -225,8 +225,14 @@ Minipush 1.0
 diff -uNr 09_hw_debug_JTAG/src/_arch/aarch64/cpu.rs 10_privilege_level/src/_arch/aarch64/cpu.rs
 --- 09_hw_debug_JTAG/src/_arch/aarch64/cpu.rs
 +++ 10_privilege_level/src/_arch/aarch64/cpu.rs
-@@ -21,18 +21,59 @@
- #[naked]
+@@ -18,22 +18,65 @@
+ /// # Safety
+ ///
+ /// - Linker script must ensure to place this function where it is expected by the target machine.
+-/// - We have to hope that the compiler omits any stack pointer usage before the stack pointer is
+-///   actually set (`SP.set()`).
++/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
++///   a stack for EL2.
  #[no_mangle]
  pub unsafe fn _start() -> ! {
 -    use crate::runtime_init;
@@ -252,6 +258,8 @@ diff -uNr 09_hw_debug_JTAG/src/_arch/aarch64/cpu.rs 10_privilege_level/src/_arch
 +/// - The HW state of EL1 must be prepared in a sound way.
 +/// - Exception return from EL2 must must continue execution in EL1 with
 +///   `runtime_init::runtime_init()`.
++/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
++///   a stack for EL2.
 +#[inline(always)]
 +unsafe fn el2_to_el1_transition() -> ! {
 +    use crate::runtime_init;

10_privilege_level/src/_arch/aarch64/cpu.rs

@@ -17,8 +17,9 @@ use cortex_a::{asm, regs::*};
 ///
 /// # Safety
 ///
-/// - Linker script must ensure to place this function at `0x80_000`.
-#[naked]
+/// - Linker script must ensure to place this function where it is expected by the target machine.
+/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
+///   a stack for EL2.
 #[no_mangle]
 pub unsafe fn _start() -> ! {
     // Expect the boot core to start in EL2.
@@ -39,6 +40,8 @@ pub unsafe fn _start() -> ! {
 /// - The HW state of EL1 must be prepared in a sound way.
 /// - Exception return from EL2 must must continue execution in EL1 with
 ///   `runtime_init::runtime_init()`.
+/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
+///   a stack for EL2.
 #[inline(always)]
 unsafe fn el2_to_el1_transition() -> ! {
     use crate::runtime_init;

11_virtual_mem_part1_identity_mapping/src/_arch/aarch64/cpu.rs

@@ -17,8 +17,9 @@ use cortex_a::{asm, regs::*};
 ///
 /// # Safety
 ///
-/// - Linker script must ensure to place this function at `0x80_000`.
-#[naked]
+/// - Linker script must ensure to place this function where it is expected by the target machine.
+/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
+///   a stack for EL2.
 #[no_mangle]
 pub unsafe fn _start() -> ! {
     // Expect the boot core to start in EL2.
@@ -39,6 +40,8 @@ pub unsafe fn _start() -> ! {
 /// - The HW state of EL1 must be prepared in a sound way.
 /// - Exception return from EL2 must must continue execution in EL1 with
 ///   `runtime_init::runtime_init()`.
+/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
+///   a stack for EL2.
 #[inline(always)]
 unsafe fn el2_to_el1_transition() -> ! {
     use crate::runtime_init;

12_exceptions_part1_groundwork/src/_arch/aarch64/cpu.rs

@@ -17,8 +17,9 @@ use cortex_a::{asm, regs::*};
 ///
 /// # Safety
 ///
-/// - Linker script must ensure to place this function at `0x80_000`.
-#[naked]
+/// - Linker script must ensure to place this function where it is expected by the target machine.
+/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
+///   a stack for EL2.
 #[no_mangle]
 pub unsafe fn _start() -> ! {
     // Expect the boot core to start in EL2.
@@ -39,6 +40,8 @@ pub unsafe fn _start() -> ! {
 /// - The HW state of EL1 must be prepared in a sound way.
 /// - Exception return from EL2 must must continue execution in EL1 with
 ///   `runtime_init::runtime_init()`.
+/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
+///   a stack for EL2.
 #[inline(always)]
 unsafe fn el2_to_el1_transition() -> ! {
     use crate::runtime_init;

13_integrated_testing/README.md

@@ -935,7 +935,7 @@ diff -uNr 12_exceptions_part1_groundwork/Makefile 13_integrated_testing/Makefile
 diff -uNr 12_exceptions_part1_groundwork/src/_arch/aarch64/cpu.rs 13_integrated_testing/src/_arch/aarch64/cpu.rs
 --- 12_exceptions_part1_groundwork/src/_arch/aarch64/cpu.rs
 +++ 13_integrated_testing/src/_arch/aarch64/cpu.rs
-@@ -87,3 +87,20 @@
+@@ -90,3 +90,20 @@
          asm::wfe()
      }
  }

13_integrated_testing/src/_arch/aarch64/cpu.rs

@@ -17,8 +17,9 @@ use cortex_a::{asm, regs::*};
 ///
 /// # Safety
 ///
-/// - Linker script must ensure to place this function at `0x80_000`.
-#[naked]
+/// - Linker script must ensure to place this function where it is expected by the target machine.
+/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
+///   a stack for EL2.
 #[no_mangle]
 pub unsafe fn _start() -> ! {
     // Expect the boot core to start in EL2.
@@ -39,6 +40,8 @@ pub unsafe fn _start() -> ! {
 /// - The HW state of EL1 must be prepared in a sound way.
 /// - Exception return from EL2 must must continue execution in EL1 with
 ///   `runtime_init::runtime_init()`.
+/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
+///   a stack for EL2.
 #[inline(always)]
 unsafe fn el2_to_el1_transition() -> ! {
     use crate::runtime_init;

14_exceptions_part2_peripheral_IRQs/src/_arch/aarch64/cpu.rs

@@ -17,8 +17,9 @@ use cortex_a::{asm, regs::*};
 ///
 /// # Safety
 ///
-/// - Linker script must ensure to place this function at `0x80_000`.
-#[naked]
+/// - Linker script must ensure to place this function where it is expected by the target machine.
+/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
+///   a stack for EL2.
 #[no_mangle]
 pub unsafe fn _start() -> ! {
     // Expect the boot core to start in EL2.
@@ -39,6 +40,8 @@ pub unsafe fn _start() -> ! {
 /// - The HW state of EL1 must be prepared in a sound way.
 /// - Exception return from EL2 must must continue execution in EL1 with
 ///   `runtime_init::runtime_init()`.
+/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
+///   a stack for EL2.
 #[inline(always)]
 unsafe fn el2_to_el1_transition() -> ! {
     use crate::runtime_init;

15_virtual_mem_part2_mmio_remap/README.md

@@ -311,7 +311,7 @@ Minipush 1.0
 diff -uNr 14_exceptions_part2_peripheral_IRQs/src/_arch/aarch64/cpu.rs 15_virtual_mem_part2_mmio_remap/src/_arch/aarch64/cpu.rs
 --- 14_exceptions_part2_peripheral_IRQs/src/_arch/aarch64/cpu.rs
 +++ 15_virtual_mem_part2_mmio_remap/src/_arch/aarch64/cpu.rs
-@@ -68,7 +68,7 @@
+@@ -71,7 +71,7 @@
      ELR_EL2.set(runtime_init::runtime_init as *const () as u64);
 
      // Set up SP_EL1 (stack pointer), which will be used by EL1 once we "return" to it.

15_virtual_mem_part2_mmio_remap/src/_arch/aarch64/cpu.rs

@@ -17,8 +17,9 @@ use cortex_a::{asm, regs::*};
 ///
 /// # Safety
 ///
-/// - Linker script must ensure to place this function at `0x80_000`.
-#[naked]
+/// - Linker script must ensure to place this function where it is expected by the target machine.
+/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
+///   a stack for EL2.
 #[no_mangle]
 pub unsafe fn _start() -> ! {
     // Expect the boot core to start in EL2.
@@ -39,6 +40,8 @@ pub unsafe fn _start() -> ! {
 /// - The HW state of EL1 must be prepared in a sound way.
 /// - Exception return from EL2 must must continue execution in EL1 with
 ///   `runtime_init::runtime_init()`.
+/// - We have to hope that the compiler omits any stack pointer usage, because we are not setting up
+///   a stack for EL2.
 #[inline(always)]
 unsafe fn el2_to_el1_transition() -> ! {
     use crate::runtime_init;

X1_JTAG_boot/jtag_boot_rpi3.img

@@ -17,8 +17,9 @@ use cortex_a::{asm, regs::*};
 ///
 /// # Safety
 ///
-/// - Linker script must ensure to place this function at `0x80_000`.
-#[naked]
+/// - Linker script must ensure to place this function where it is expected by the target machine.
+/// - We have to hope that the compiler omits any stack pointer usage before the stack pointer is
+///   actually set (`SP.set()`).
 #[no_mangle]
 pub unsafe fn _start() -> ! {
     use crate::runtime_init;

X1_JTAG_boot/jtag_boot_rpi4.img

@@ -1,4 +1,4 @@
 [toolchain]
-channel = "nightly-2020-12-08"
+channel = "nightly-2020-12-09"
 components = ["llvm-tools-preview"]
 targets = ["aarch64-unknown-none-softfloat"]