Add support for board native_sim/native/64

This allows the native_sim/native/64 target to build on both x86_64 and
aarch64 Linux.

Currently 32-bit native_sim is not supported, as upstream rust does not
build std/core/alloc for the unknown-none variants of these targets.

This adds the "zephyr,sim-flash" device so that the generated DT will
compile.

Based on a contribution by:

    Author: Evan Perry Grove <[email protected]>
    Date:   Wed Jan 29 13:00:29 2025 -0600

Signed-off-by: Evan Perry Grove <[email protected]>
Signed-off-by: David Brown <[email protected]>

Author: d3zd3z

.github/workflows/build.yml

@@ -54,6 +54,8 @@ jobs:
           rustup target add thumbv7em-none-eabi
           rustup target add thumbv7m-none-eabi
           rustup target add thumbv8m.main-none-eabi
+          rustup target add x86_64-unknown-none
+          rustup target add aarch64-unknown-none
 
       # Note that Renode is only provided for x86_64 targets.  This matches the github runners.
       - name: Install Renode

CMakeLists.txt

@@ -49,6 +49,10 @@ function(_rust_map_target)
     else()
       message(FATAL_ERROR "Rust: Unsupported riscv ISA")
     endif()
+  elseif(CONFIG_ARCH_POSIX AND CONFIG_64BIT AND (${CMAKE_HOST_SYSTEM_PROCESSOR} MATCHES "x86_64"))
+    set(RUST_TARGET "x86_64-unknown-none" PARENT_SCOPE)
+  elseif(CONFIG_ARCH_POSIX AND CONFIG_64BIT AND (${CMAKE_HOST_SYSTEM_PROCESSOR} MATCHES "aarch64"))
+    set(RUST_TARGET "aarch64-unknown-none" PARENT_SCOPE)
   else()
     message(FATAL_ERROR "Rust: Add support for other target")
   endif()

Kconfig

@@ -8,7 +8,8 @@ menu "Rust Language Support"
 config RUST_SUPPORTED
 	bool
 	default y if ((CPU_CORTEX_M || \
-				(RISCV && !RISCV_ISA_RV32E && !RISCV_ISA_RV128I)) && \
+				(RISCV && !RISCV_ISA_RV32E && !RISCV_ISA_RV128I) || \
+				(ARCH_POSIX && 64BIT)) && \
 				!TIMER_READS_ITS_FREQUENCY_AT_RUNTIME)
 	help
 	  Selected for platforms that have support for Rust.

dt-rust.yaml

@@ -45,6 +45,7 @@
       - "nordic,nrf52-flash-controller"
       - "nordic,nrf51-flash-controller"
       - "raspberrypi,pico-flash-controller"
+      - "zephyr,sim-flash"
       level: 0
   actions:
   - type: instance