Swift Forums

Linux RISCV64 Support

Development Compiler

ColemanCDA (Alsey Coleman Miller) March 18, 2022, 1:53am #1

I have been working on patches for compiling Swift 5.6 for RISCV64 with Buildroot. First I compiled the patched compiler (swift, llvm-project and swift-core-tools-support) and then use Buildroot with patched compiler to cross compiler the Swift Stdlib. I have gotten to the point where I can successfully compile libdispatch, the Swift StdLib and runtime's .c, .cpp and .swift files for RISCV64, but the linking stage for the StdLib fails.

https://bugs.swift.org/browse/SR-16005

ld.lld: error: stdlib/public/core/LINUX/riscv64/Swift.o: cannot link object files with different floating-point ABI
ld.lld: error: Swift.o![|16x16](https://bugs.swift.org/images/icons/emoticons/sad.png).text+0x0): relocation R_RISCV_ALIGN requires unimplemented linker relaxation; recompile with -mno-relax

I have tried a lot of Swift compiler flags based on Every Option and Flag /swift (1.2) Accepts Ever · GitHub and passing them via -DSWIFT_STDLIB_EXTRA_SWIFT_COMPILE_FLAGS to cmake for cross compiling the StdLib but none seem to work.

8 Likes

ColemanCDA (Alsey Coleman Miller) March 27, 2022, 6:43am #2

I was able to build for RISCV64 with Soft Float enabled.

ColemanCDA (Alsey Coleman Miller) March 27, 2022, 6:49am #3

Swift patches

gist.github.com

https://gist.github.com/colemancda/a6112d449b76eddf12dfa46e260bfca0

swift-5.6-riscv64.patch

diff --git a/CMakeLists.txt b/CMakeLists.txt
index bc9b6790922..6cc8149e184 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -724,6 +724,8 @@ else()
     set(SWIFT_HOST_VARIANT_ARCH_default "i686")
   elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "wasm32")
     set(SWIFT_HOST_VARIANT_ARCH_default "wasm32")
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "riscv64")
+    set(SWIFT_HOST_VARIANT_ARCH_default "riscv64")

This file has been truncated. show original

gist.github.com

https://gist.github.com/colemancda/bab5a634176b53f0f8c76d6ab5eec578

llvm-5.6-riscv64.patch

diff --git a/clang/lib/Basic/Targets/RISCV.h b/clang/lib/Basic/Targets/RISCV.h
index 7e0846581ca1..60d676ee1761 100644
--- a/clang/lib/Basic/Targets/RISCV.h
+++ b/clang/lib/Basic/Targets/RISCV.h
@@ -111,7 +111,19 @@ public:
                             DiagnosticsEngine &Diags) override;
 
   bool hasExtIntType() const override { return true; }
+
+  CallingConvCheckResult checkCallingConvention(CallingConv CC) const override {

This file has been truncated. show original

gist.github.com

https://gist.github.com/colemancda/840a1d6e2029c31f899a91e503c2364b

swift-tools-5.6-riscv64.patch

diff --git a/Sources/TSCUtility/Triple.swift b/Sources/TSCUtility/Triple.swift
index 0b682c8..5b21571 100644
--- a/Sources/TSCUtility/Triple.swift
+++ b/Sources/TSCUtility/Triple.swift
@@ -49,6 +49,7 @@ public struct Triple: Encodable, Equatable {
         case arm64
         case arm64e
         case wasm32
+        case riscv64
     }

This file has been truncated. show original

Buildroot

gist.github.com

https://gist.github.com/colemancda/2716a33bc87b518a83a46ac520d412f1

swift-5.6-riscv-buildroot-config

#
# Automatically generated file; DO NOT EDIT.
# Buildroot 2022.02-390-gcf37c90de7-dirty Configuration
#
BR2_HAVE_DOT_CONFIG=y
BR2_HOST_GCC_AT_LEAST_4_9=y
BR2_HOST_GCC_AT_LEAST_5=y
BR2_HOST_GCC_AT_LEAST_6=y
BR2_HOST_GCC_AT_LEAST_7=y
BR2_HOST_GCC_AT_LEAST_8=y

This file has been truncated. show original

gist.github.com

https://gist.github.com/colemancda/94ab66fbf49f93748c8d7f7e11d8b8ce

qemu_riscv64_virt_defconfig

# Architecture
BR2_riscv=y
BR2_RISCV_64=y

# System
BR2_SYSTEM_DHCP="eth0"
BR2_TARGET_GENERIC_GETTY=y

# Filesystem
BR2_TARGET_ROOTFS_EXT2=y

This file has been truncated. show original

gist.github.com

https://gist.github.com/colemancda/83e681b53807e7f82517ec3b32d40cd3

swift-5.6-riscv64-buildroot.patch

diff --git a/package/Config.in b/package/Config.in
index 0d5d763180..b89a49913e 100644
--- a/package/Config.in
+++ b/package/Config.in
@@ -1422,6 +1422,7 @@ menu "Crypto"
 	source "package/openssl/Config.in"
 	source "package/pkcs11-helper/Config.in"
 	source "package/rhash/Config.in"
+	source "package/swift-crypto/Config.in"
 	source "package/tinydtls/Config.in"

This file has been truncated. show original

1 Like

Introduce embedded development using Swift

ColemanCDA (Alsey Coleman Miller) March 28, 2022, 1:07am #4

github.com/apple/swift

[stdlib] Added RISCV64 support

apple:main ← MillerTechnologyPeru:feature/riscv64

opened 05:32PM - 17 Mar 22 UTC

Added support to cross-compile the StdLib for RISCV64. Resolves [SR-16005](…https://bugs.swift.org/browse/SR-16005).

2 Likes

mickeyl (Dr. Mickey Lauer) June 7, 2022, 2:20pm #5

Amazing work!, @ColemanCDA. This has so much potential!

As a matter of fact, I just recently started to get into microcontrollers. In particular I'm supposed to write the firmware for an ESP32-C3 (RISCV32) based device and would love to use Swift rather than C and C++.

How similar are RISCV32 and RISCV64? What would it take to enhance your patch to also support RISCV32?

Terms of Service

Cookie Policy