zephyr: Add support for RISC-V RV32IMC native code emitter.

Add support for RISC-V RV32IMC native code emitter in the zephyr port.  It
will be automatically enabled by default, but can be overridden by defining
`MICROPY_EMIT_RV32` and/or `MICROPY_EMIT_INLINE_RV32`.

Signed-off-by: Fin Maaß <f.maass@vogl-electronic.com>

Author: maass-hamburg

ports/zephyr/CMakeLists.txt

@@ -37,6 +37,25 @@ include(${MICROPY_DIR}/extmod/extmod.cmake)
 
 list(APPEND DTS_ROOT ${CMAKE_CURRENT_SOURCE_DIR}/dts)
 
+# Define mpy-cross flags, for use with frozen code.
+if(CONFIG_RISCV_ISA_RV32I AND CONFIG_RISCV_ISA_EXT_M AND CONFIG_RISCV_ISA_EXT_C)
+    set(ARCH_FLAGS "")
+    set(RV32_EXT "")
+    if(CONFIG_RISCV_ISA_EXT_ZBA)
+        list(APPEND RV32_EXT "zba")
+    endif()
+    if(CONFIG_RISCV_ISA_EXT_ZCMP)
+        list(APPEND RV32_EXT "zcmp")
+    endif()
+    if(RV32_EXT)
+        list(JOIN RV32_EXT "," RV32_EXT)
+        set(ARCH_FLAGS "-march-flags=${RV32_EXT}")
+    endif()
+    set(MICROPY_CROSS_FLAGS "-march=rv32imc ${ARCH_FLAGS}")
+elseif(CONFIG_RISCV_ISA_RV64I AND CONFIG_RISCV_ISA_EXT_M AND CONFIG_RISCV_ISA_EXT_C)
+    set(MICROPY_CROSS_FLAGS -march=rv64imc)
+endif()
+
 if (CONFIG_MICROPY_FROZEN_MODULES)
     cmake_path(ABSOLUTE_PATH CONFIG_MICROPY_FROZEN_MANIFEST BASE_DIRECTORY ${CMAKE_CURRENT_LIST_DIR})
     set(MICROPY_FROZEN_MANIFEST ${CONFIG_MICROPY_FROZEN_MANIFEST})

ports/zephyr/mpconfigport.h

@@ -113,6 +113,26 @@
 #define MICROPY_VFS                 (1)
 #define MICROPY_READER_VFS          (MICROPY_VFS)
 
+#if defined(CONFIG_RISCV_ISA_RV32I) && defined(CONFIG_RISCV_ISA_EXT_M) && defined(CONFIG_RISCV_ISA_EXT_C)
+
+#ifndef MICROPY_EMIT_RV32
+#define MICROPY_EMIT_RV32        (1)
+#endif
+
+#ifndef MICROPY_EMIT_INLINE_RV32
+#define MICROPY_EMIT_INLINE_RV32 (1)
+#endif
+
+#ifdef CONFIG_RISCV_ISA_EXT_ZBA
+#define MICROPY_EMIT_RV32_ZBA (1)
+#endif
+
+#ifdef CONFIG_RISCV_ISA_EXT_ZCMP
+#define MICROPY_EMIT_RV32_ZCMP (1)
+#endif
+
+#endif // CONFIG_RISCV_ISA_RV32I
+
 // fatfs configuration used in ffconf.h
 #define MICROPY_FATFS_ENABLE_LFN       (1)
 #define MICROPY_FATFS_LFN_CODE_PAGE    437 /* 1=SFN/ANSI 437=LFN/U.S.(OEM) */