Change to new aarch64-unknown-none-softloat target.

Also, add safety docs where demanded by clippy.

01_bareminimum/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

01_bareminimum/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

01_bareminimum/README.md

@@ -26,9 +26,9 @@ much as possible, we are already setting up a Rust crate. This allows us to use
 
 The Raspberry Pi 3 features a processor that uses ARM's `AArch64` architecture.
 Conveniently, Rust already provides a generic target for bare-metal aarch64 code
-that we can leverage. It is called [aarch64-unknown-none].
+that we can leverage. It is called [aarch64-unknown-none-softfloat].
 
-[aarch64-unknown-none]: https://github.com/andre-richter/rust/blob/master/src/librustc_target/spec/aarch64_unknown_none.rs
+[aarch64-unknown-none-softfloat]: https://github.com/rust-lang/rust/blob/master/src/librustc_target/spec/aarch64_unknown_none_softfloat.rs
 
 In the `Makefile`, we select this target in various places by passing it to
 cargo using the `--target` cmdline argument.
@@ -37,17 +37,20 @@ Additionally, we provide a config file in `.cargo/config` were we make further
 specializations:
 
 ```toml
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]
 ```
 
-The first line tells rustc to use our custom `link.ld` linker script. The second
-line instructs the compiler to not use floating point operations. This is a
-common choice when writing an operating system kernel. If floating point is not
+The first line tells rustc to use our custom `link.ld` linker script. The
+second argument specifies the exact CPU type that is used on Raspberry Pi 3, so
+that the compiler can optimize for it.
+
+The target itself tells the compiler already to not use floating point
+operations, which is hinted by the `-softfloat` appendix. This is a common
+choice when writing an operating system kernel. If floating point is not
 explicitly disabled, it is possible that the compiler uses auto-vectorization to
 optimize, for example, operations on array data structures. This would
 implicitly result in use of floating point registers and operations. However,
@@ -55,10 +58,7 @@ since it is very costly to save and restore floating point registers during
 context-switches, use of fp is usually disabled from the get go to save the
 cycles and optimize the kernel for fast context switching.
 
-Finally, the third arguments specifies the exact CPU type that is used in
-Raspberry Pi 3, so that the compiler can optimize for it.
-
-Since the `aarch64-unknown-none` target is not shipped with an associated
+Since the `aarch64-unknown-none-softfloat` target is not shipped with an associated
 precompiled standard library, and since we anyways modify the target via the
 `.cargo/config` file, we are using [cargo-xbuild][xbuild] to compile our own
 standard library. This way, we can ensure that our bare-metal code is optimized

02_multicore_rust/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

02_multicore_rust/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

02_multicore_rust/raspi3_boot/src/lib.rs

@@ -36,6 +36,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -49,6 +53,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 #[no_mangle]
 pub unsafe extern "C" fn reset() -> ! {
     extern "C" {

03_uart1/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

03_uart1/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

03_uart1/raspi3_boot/src/lib.rs

@@ -36,6 +36,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -49,6 +53,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 #[no_mangle]
 pub unsafe extern "C" fn reset() -> ! {
     extern "C" {

04_mailboxes/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

04_mailboxes/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

04_mailboxes/raspi3_boot/src/lib.rs

@@ -36,6 +36,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -49,6 +53,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 #[no_mangle]
 pub unsafe extern "C" fn reset() -> ! {
     extern "C" {

05_uart0/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

05_uart0/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

05_uart0/raspi3_boot/src/lib.rs

@@ -36,6 +36,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -49,6 +53,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 #[no_mangle]
 pub unsafe extern "C" fn reset() -> ! {
     extern "C" {

06_raspbootin64/.cargo/config

@@ -1,7 +1,6 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
   "-C", "relocation-model=pic",
 ]

06_raspbootin64/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

06_raspbootin64/README.md

@@ -92,10 +92,9 @@ To enable PIC for our loader, we add the following line to the compiler flags in
 the`.cargo/config`:
 
 ```toml
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
   "-C", "relocation-model=pic", # <-- New
 ]

06_raspbootin64/raspi3_boot/src/lib.rs

@@ -36,6 +36,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -49,6 +53,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Trampolines into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 #[no_mangle]
 pub unsafe extern "C" fn reset() -> ! {
     extern "Rust" {

07_abstraction/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

07_abstraction/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

07_abstraction/README.md

@@ -93,7 +93,7 @@ should yield something like the following, where you can see that the stack
 pointer is not used apart from ourselves setting it.
 
 ```console
-ferris@box:~$ cargo objdump --target aarch64-unknown-none -- -disassemble -print-imm-hex kernel8
+ferris@box:~$ cargo objdump --target aarch64-unknown-none-softfloat -- -disassemble -print-imm-hex kernel8
 
 [...] (Some output omitted)
 

07_abstraction/raspi3_boot/src/lib.rs

@@ -35,6 +35,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -48,6 +52,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 unsafe fn reset() -> ! {
     extern "C" {
         // Boundaries of the .bss section, provided by the linker script
@@ -69,6 +77,10 @@ unsafe fn reset() -> ! {
 ///
 /// Parks all cores except core0, and then jumps to the internal
 /// `reset()` function.
+///
+/// # Safety
+///
+/// - Linker script must ensure to place this function at `0x80_000`.
 #[link_section = ".text.boot"]
 #[no_mangle]
 pub unsafe extern "C" fn _boot_cores() -> ! {

08_random/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

08_random/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

08_random/raspi3_boot/src/lib.rs

@@ -35,6 +35,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -48,6 +52,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 unsafe fn reset() -> ! {
     extern "C" {
         // Boundaries of the .bss section, provided by the linker script
@@ -69,6 +77,10 @@ unsafe fn reset() -> ! {
 ///
 /// Parks all cores except core0, and then jumps to the internal
 /// `reset()` function.
+///
+/// # Safety
+///
+/// - Linker script must ensure to place this function at `0x80_000`.
 #[link_section = ".text.boot"]
 #[no_mangle]
 pub unsafe extern "C" fn _boot_cores() -> ! {

09_delays/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

09_delays/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

09_delays/raspi3_boot/src/lib.rs

@@ -35,6 +35,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -48,6 +52,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 unsafe fn reset() -> ! {
     extern "C" {
         // Boundaries of the .bss section, provided by the linker script
@@ -69,6 +77,10 @@ unsafe fn reset() -> ! {
 ///
 /// Parks all cores except core0, and then jumps to the internal
 /// `reset()` function.
+///
+/// # Safety
+///
+/// - Linker script must ensure to place this function at `0x80_000`.
 #[link_section = ".text.boot"]
 #[no_mangle]
 pub unsafe extern "C" fn _boot_cores() -> ! {

0A_power/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

0A_power/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

0A_power/raspi3_boot/src/lib.rs

@@ -35,6 +35,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -48,6 +52,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 unsafe fn reset() -> ! {
     extern "C" {
         // Boundaries of the .bss section, provided by the linker script
@@ -69,6 +77,10 @@ unsafe fn reset() -> ! {
 ///
 /// Parks all cores except core0, and then jumps to the internal
 /// `reset()` function.
+///
+/// # Safety
+///
+/// - Linker script must ensure to place this function at `0x80_000`.
 #[link_section = ".text.boot"]
 #[no_mangle]
 pub unsafe extern "C" fn _boot_cores() -> ! {

0B_hw_debug_JTAG/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

0B_hw_debug_JTAG/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

0B_hw_debug_JTAG/raspi3_boot/src/lib.rs

@@ -35,6 +35,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -48,6 +52,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 unsafe fn reset() -> ! {
     extern "C" {
         // Boundaries of the .bss section, provided by the linker script
@@ -69,6 +77,10 @@ unsafe fn reset() -> ! {
 ///
 /// Parks all cores except core0, and then jumps to the internal
 /// `reset()` function.
+///
+/// # Safety
+///
+/// - Linker script must ensure to place this function at `0x80_000`.
 #[link_section = ".text.boot"]
 #[no_mangle]
 pub unsafe extern "C" fn _boot_cores() -> ! {

0C_exception_levels/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

0C_exception_levels/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

0C_exception_levels/README.md

@@ -122,7 +122,7 @@ do not have a stack yet. We should double-check the generated machine code:
 
 ```console
 ferris@box:~$ make objdump
-cargo objdump --target aarch64-unknown-none -- -disassemble -print-imm-hex kernel8
+cargo objdump --target aarch64-unknown-none-softfloat -- -disassemble -print-imm-hex kernel8
 
 kernel8:	file format ELF64-aarch64-little
 

0C_exception_levels/raspi3_boot/src/lib.rs

@@ -35,6 +35,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -48,6 +52,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 unsafe fn reset() -> ! {
     extern "C" {
         // Boundaries of the .bss section, provided by the linker script
@@ -109,6 +117,10 @@ fn setup_and_enter_el1_from_el2() -> ! {
 ///
 /// Parks all cores except core0 and checks if we started in EL2. If
 /// so, proceeds with setting up EL1.
+///
+/// # Safety
+///
+/// - Linker script must ensure to place this function at `0x80_000`.
 #[link_section = ".text.boot"]
 #[no_mangle]
 pub unsafe extern "C" fn _boot_cores() -> ! {

0D_virtual_memory/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

0D_virtual_memory/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

0D_virtual_memory/raspi3_boot/src/lib.rs

@@ -35,6 +35,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -48,6 +52,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 unsafe fn reset() -> ! {
     extern "C" {
         // Boundaries of the .bss section, provided by the linker script
@@ -109,6 +117,10 @@ fn setup_and_enter_el1_from_el2() -> ! {
 ///
 /// Parks all cores except core0 and checks if we started in EL2. If
 /// so, proceeds with setting up EL1.
+///
+/// # Safety
+///
+/// - Linker script must ensure to place this function at `0x80_000`.
 #[link_section = ".text.boot"]
 #[no_mangle]
 pub unsafe extern "C" fn _boot_cores() -> ! {

0D_virtual_memory/src/memory/mmu.rs

@@ -276,6 +276,10 @@ static mut LVL3_TABLE: PageTable = PageTable {
 /// Set up identity mapped page tables for the first 1 GiB of address space.
 ///
 /// The first 2 MiB are 4 KiB granule, the rest 2 MiB.
+///
+/// # Safety
+///
+/// - User must ensure that the hardware supports the paremeters being set here.
 pub unsafe fn init() -> Result<(), &'static str> {
     // Prepare the memory attribute indirection register.
     set_up_mair();

0E_cache_performance/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

0E_cache_performance/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

0E_cache_performance/raspi3_boot/src/lib.rs

@@ -35,6 +35,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -48,6 +52,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 unsafe fn reset() -> ! {
     extern "C" {
         // Boundaries of the .bss section, provided by the linker script
@@ -109,6 +117,10 @@ fn setup_and_enter_el1_from_el2() -> ! {
 ///
 /// Parks all cores except core0 and checks if we started in EL2. If
 /// so, proceeds with setting up EL1.
+///
+/// # Safety
+///
+/// - Linker script must ensure to place this function at `0x80_000`.
 #[link_section = ".text.boot"]
 #[no_mangle]
 pub unsafe extern "C" fn _boot_cores() -> ! {

0E_cache_performance/src/memory/mmu.rs

@@ -266,6 +266,10 @@ static mut LVL3_TABLE: PageTable = PageTable {
 /// Set up identity mapped page tables for the first 1 GiB of address space.
 ///
 /// The first 2 MiB are 4 KiB granule, the rest 2 MiB.
+///
+/// # Safety
+///
+/// - User must ensure that the hardware supports the paremeters being set here.
 pub unsafe fn init() -> Result<(), &'static str> {
     // Prepare the memory attribute indirection register.
     set_up_mair();

0F_globals_synchronization_println/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

0F_globals_synchronization_println/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

0F_globals_synchronization_println/raspi3_boot/src/lib.rs

@@ -35,6 +35,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -48,6 +52,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 unsafe fn reset() -> ! {
     extern "C" {
         // Boundaries of the .bss section, provided by the linker script
@@ -109,6 +117,10 @@ fn setup_and_enter_el1_from_el2() -> ! {
 ///
 /// Parks all cores except core0 and checks if we started in EL2. If
 /// so, proceeds with setting up EL1.
+///
+/// # Safety
+///
+/// - Linker script must ensure to place this function at `0x80_000`.
 #[link_section = ".text.boot"]
 #[no_mangle]
 pub unsafe extern "C" fn _boot_cores() -> ! {

0F_globals_synchronization_println/src/memory/mmu.rs

@@ -266,6 +266,10 @@ static mut LVL3_TABLE: PageTable = PageTable {
 /// Set up identity mapped page tables for the first 1 GiB of address space.
 ///
 /// The first 2 MiB are 4 KiB granule, the rest 2 MiB.
+///
+/// # Safety
+///
+/// - User must ensure that the hardware supports the paremeters being set here.
 pub unsafe fn init() -> Result<(), &'static str> {
     // Prepare the memory attribute indirection register.
     set_up_mair();

10_DMA_memory/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

10_DMA_memory/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

10_DMA_memory/raspi3_boot/src/lib.rs

@@ -35,6 +35,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -48,6 +52,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 unsafe fn reset() -> ! {
     extern "C" {
         // Boundaries of the .bss section, provided by the linker script
@@ -109,6 +117,10 @@ fn setup_and_enter_el1_from_el2() -> ! {
 ///
 /// Parks all cores except core0 and checks if we started in EL2. If
 /// so, proceeds with setting up EL1.
+///
+/// # Safety
+///
+/// - Linker script must ensure to place this function at `0x80_000`.
 #[link_section = ".text.boot"]
 #[no_mangle]
 pub unsafe extern "C" fn _boot_cores() -> ! {

10_DMA_memory/src/memory/mmu.rs

@@ -266,6 +266,10 @@ static mut LVL3_TABLE: PageTable = PageTable {
 /// Set up identity mapped page tables for the first 1 GiB of address space.
 ///
 /// The first 2 MiB are 4 KiB granule, the rest 2 MiB.
+///
+/// # Safety
+///
+/// - User must ensure that the hardware supports the paremeters being set here.
 pub unsafe fn init() -> Result<(), &'static str> {
     // Prepare the memory attribute indirection register.
     set_up_mair();

11_exceptions_groundwork/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

11_exceptions_groundwork/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

11_exceptions_groundwork/raspi3_boot/src/lib.rs

@@ -35,6 +35,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -48,6 +52,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 unsafe fn reset() -> ! {
     extern "C" {
         // Boundaries of the .bss section, provided by the linker script
@@ -109,6 +117,10 @@ fn setup_and_enter_el1_from_el2() -> ! {
 ///
 /// Parks all cores except core0 and checks if we started in EL2. If
 /// so, proceeds with setting up EL1.
+///
+/// # Safety
+///
+/// - Linker script must ensure to place this function at `0x80_000`.
 #[link_section = ".text.boot"]
 #[no_mangle]
 pub unsafe extern "C" fn _boot_cores() -> ! {

11_exceptions_groundwork/src/exception.rs

@@ -27,6 +27,10 @@ use cortex_a::{barrier, regs::*};
 
 global_asm!(include_str!("vectors.S"));
 
+/// # Safety
+///
+/// - User must ensure to call this function at a suitable place, since it
+///   changes the state of the hardware.
 pub unsafe fn set_vbar_el1_checked(vec_base_addr: u64) -> bool {
     if vec_base_addr.trailing_zeros() < 11 {
         false

11_exceptions_groundwork/src/memory/mmu.rs

@@ -266,6 +266,10 @@ static mut LVL3_TABLE: PageTable = PageTable {
 /// Set up identity mapped page tables for the first 1 GiB of address space.
 ///
 /// The first 2 MiB are 4 KiB granule, the rest 2 MiB.
+///
+/// # Safety
+///
+/// - User must ensure that the hardware supports the paremeters being set here.
 pub unsafe fn init() -> Result<(), &'static str> {
     // Prepare the memory attribute indirection register.
     set_up_mair();

X1_JTAG_boot/.cargo/config

@@ -1,6 +1,5 @@
-[target.aarch64-unknown-none]
+[target.aarch64-unknown-none-softfloat]
 rustflags = [
   "-C", "link-arg=-Tlink.ld",
-  "-C", "target-feature=-fp-armv8",
   "-C", "target-cpu=cortex-a53",
 ]

X1_JTAG_boot/Makefile

@@ -22,7 +22,7 @@
 # SOFTWARE.
 #
 
-TARGET = aarch64-unknown-none
+TARGET = aarch64-unknown-none-softfloat
 
 SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) link.ld
 

X1_JTAG_boot/raspi3_boot/src/lib.rs

@@ -35,6 +35,10 @@ extern crate panic_abort;
 #[macro_export]
 macro_rules! entry {
     ($path:path) => {
+        /// # Safety
+        ///
+        /// - User must ensure to provide a suitable main function for the
+        ///   platform.
         #[export_name = "main"]
         pub unsafe fn __main() -> ! {
             // type check the given path
@@ -48,6 +52,10 @@ macro_rules! entry {
 /// Reset function.
 ///
 /// Initializes the bss section before calling into the user's `main()`.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
 unsafe fn reset() -> ! {
     extern "C" {
         // Boundaries of the .bss section, provided by the linker script
@@ -69,6 +77,10 @@ unsafe fn reset() -> ! {
 ///
 /// Parks all cores except core0, and then jumps to the internal
 /// `reset()` function.
+///
+/// # Safety
+///
+/// - Linker script must ensure to place this function at `0x80_000`.
 #[link_section = ".text.boot"]
 #[no_mangle]
 pub unsafe extern "C" fn _boot_cores() -> ! {