wasm-micro-runtime/doc/port_wamr.md

WAMR porting guide

This document describes how to port WAMR to a new platform "super-os"

Step 1: Create folders for the new platform

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Create folders:

• core/shared/platform/super-os: for platform API layer implementations
• product-mini/platforms/super-os: for the platform mini product build

Step 2: Implement platform API layer

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Implement folder core/shared/platform/super-os. Normally in this folder you should implement the following files:

• bh_platform.h and bh_platform.c: define the platform related macros, data types and APIs.
• bh_assert.c: implement function bh_assert_internal() and bh_debug_internal().
• bh_platform_log.c: implement function bh_log_emit, bh_fprintf and bh_fflush.
• bh_time.c: implement several time related functions.
• bh_thread.c: implement thread, mutex, condition related functions.
• bh_math.c: implement some math functions if the platform doesn't support them, e.g. sqrt, fabs and isnan. We may use the open source fdlibm implementation, for example, ref to platform/zephyr/bh_math.c.

Please ref to implementation of other platform for more details, e.g. platform/zephyr, platform/linux.

Step 3: Create the mini product build for the platform

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Implement folder product-mini/platforms/super-os. Normally this folder is to implement the C main function, and generate a WAMR VM core binary named iwasm which can load and run wasm apps. We should implement following files:

• main.c: implement the C main function, which reads wasm file to buffer, loads the wasm file to wasm module, instantiate the module, lookup wasm app main function, and then execute the function.
• ext_lib_export.c: implement the native APIs if you want, and if no native API is to be implemented, just keep array extended_native_symbol_defs empty.
• CMakeLists.txt: there are some settings which can be passed from cmake variables:
  • set (WAMR_BUILD_PLATFORM "platform_name"): set the name of the platform
  • set (WAMR_BUILD_TARGET _{): set the build target, currently the value supported: X86_64, X86_32, ARM[sub], THUMB[sub], MIPS and XTENSA. For ARM and THUMB, you can specify the sub version, e.g. ARMV4, ARMV7, THUMBV4T, THUMBV7T.}
  • set (WAMR_BUILD_INTERP 1 or 0): whether to interpreter or not
  • set (WAMR_BUILD_AOT 1 or 0): whether to build AOT or not
  • set (WAMR_BUILD_JIT 1 or 0): whether to build JIT or not
  • set (WAMR_BUILD_LIBC_BUILTIN 1 or 0): whether to build Libc builtin or not
  • set (WAMR_BUILD_LIBC_WASI 1 or 0): whether to build Libc WASI or not