Try swift-mmio

[kkebo]

swift-mmio might be suitable for swift_os.

However, I have not succeeded in building swift_os with swift-mmio added as an external dependency.

On the other hand, swift-embedded-examples has succeeded in doing it. I don't know what's the difference between them.

Logs:

$ swift --version
Swift version 6.0-dev (LLVM 3b959ba388a8ad9, Swift bb339b8f50f01fb)
Target: aarch64-unknown-linux-gnu
$ git diff
diff --git a/Package.swift b/Package.swift
index 9e41ccc..253a73d 100644
--- a/Package.swift
+++ b/Package.swift
@@ -7,12 +7,16 @@ let package = Package(
     products: [
         .library(name: "Kernel", type: .static, targets: ["Kernel"])
     ],
+    dependencies: [
+        .package(url: "https://github.com/apple/swift-mmio", branch: "swift-embedded-examples")
+    ],
     targets: [
         .target(
             name: "Kernel",
             dependencies: [
                 "Volatile",
                 "MailboxMessage",
+                .product(name: "MMIO", package: "swift-mmio"),
             ],
             swiftSettings: [
                 .enableExperimentalFeature("Embedded"),
$ make
clang -x assembler -target aarch64-none-none-elf -c boot.s -o boot.o
clang -x assembler -target aarch64-none-none-elf -c asmfunc.s -o asmfunc.o
swift build --triple aarch64-none-none-elf -c release
Building for production...
<unknown>:0: error: unable to load standard library for target 'aarch64-none-none-elf'
<unknown>:0: error: unable to load standard library for target 'aarch64-none-none-elf'

make: *** [Makefile:25: swift] Error 1

[kkebo]

I built with --static-swift-stdlib and nothing changed.

[kkebo]

On Linux, stm32-uart-echo cannot be built with make too. So swift-mmio might be usable only on macOS.

$ swift --version
Swift version 6.0-dev (LLVM 3b959ba388a8ad9, Swift bb339b8f50f01fb)
Target: aarch64-unknown-linux-gnu
$ git diff
diff --git a/stm32-uart-echo/Makefile b/stm32-uart-echo/Makefile
index 5d1c929..df6269c 100755
--- a/stm32-uart-echo/Makefile
+++ b/stm32-uart-echo/Makefile
@@ -17,10 +17,10 @@ BUILDROOT := $(SRCROOT)/.build/release
 
 # Setup tools and build flags
 ARCH := armv7em
-TARGET := $(ARCH)-apple-none-macho
+TARGET := $(ARCH)-none-none-eabi
 VECTORS_ADDRESS=-0x00200000
 
-SWIFT_BUILD := $(shell xcrun -f swift-build)
+SWIFT_BUILD := swift build
 MACHO2BIN := $(SRCROOT)/../Tools/macho2bin.py
 
 .PHONY: build
diff --git a/stm32-uart-echo/Sources/Support/startup.S b/stm32-uart-echo/Sources/Support/startup.S
index 6e8c7c2..4328465 100644
--- a/stm32-uart-echo/Sources/Support/startup.S
+++ b/stm32-uart-echo/Sources/Support/startup.S
@@ -14,7 +14,6 @@
 
   .text
   .thumb
-  .section __TEXT,__text,regular,pure_instructions
   .syntax unified
 
 // reset handler, main entry point
$ make
...
<unknown>:0: error: unable to load standard library for target 'armv7em-none-none-eabi'
<unknown>:0: error: unable to load standard library for target 'armv7em-none-none-eabi'
make: *** [Makefile:29: build] Error 1