Build openssl for arm64 iOS simulator - ios

Question

Description
I'm trying build iphonesimulator-only targeted library witn architecture arm64, but linking step failed with error:
${LDCMD:-/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang} -O3 -fvisibility=hidden -miphoneos-version-min=9.0 -fembed-bitcode -fPIC -arch arm64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator14.5.sdk -L. -Wl,-search_paths_first \
-o apps/openssl apps/asn1pars.o apps/ca.o apps/ciphers.o apps/cms.o apps/crl.o apps/crl2p7.o apps/dgst.o apps/dhparam.o apps/dsa.o apps/dsaparam.o apps/ec.o apps/ecparam.o apps/enc.o apps/errstr.o apps/gendsa.o apps/genpkey.o apps/genrsa.o apps/nseq.o apps/ocsp.o apps/openssl.o apps/passwd.o apps/pkcs12.o apps/pkcs7.o apps/pkcs8.o apps/pkey.o apps/pkeyparam.o apps/pkeyutl.o apps/prime.o apps/rand.o apps/rehash.o apps/req.o apps/rsa.o apps/rsautl.o apps/s_client.o apps/s_server.o apps/s_time.o apps/sess_id.o apps/smime.o apps/speed.o apps/spkac.o apps/srp.o apps/storeutl.o apps/ts.o apps/verify.o apps/version.o apps/x509.o \
apps/libapps.a -lssl -lcrypto
ld: building for iOS, but linking in .tbd file (/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator14.5.sdk/usr/lib/libSystem.tbd) built for iOS Simulator, file '/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator14.5.sdk/usr/lib/libSystem.tbd' for architecture arm64
Configuraton command:
./Configure iossimulator-xcrun threads no-shared "-fvisibility=hidden -miphoneos-version-min=9.0 -fembed-bitcode -fPIC" no-asm no-hw no-async --prefix=/Users/macosuser/Build/OpenSSL/Install "-arch arm64" "-isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator14.5.sdk"
Configuring OpenSSL version 1.1.1j (0x101010afL) for iossimulator-xcrun
Using os-specific seed configuration
Creating configdata.pm
Creating Makefile
Build commands look like this:
...
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -I. -Iinclude -Iapps -O3 -fvisibility=hidden -miphoneos-version-min=9.0 -fembed-bitcode -fPIC -arch arm64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator14.5.sdk -D_REENTRANT -DNDEBUG -MMD -MF apps/x509.d.tmp -MT apps/x509.o -c -o apps/x509.o apps/x509.c
...
Question
I can't figure out why for other architectures (i386, x86_64) the build happens without problems.
Perhaps I am missing some nuance, but I cannot understand which one.
Why do I need this - an application using this library must run on a simulator in a macbook with an M1 processor.
Environment specifications
MacOS 11.4
XCode v12.5
OpenSSL v1.1.1j
Compiler - AppleClang 12.0.5.12050022

Answer 1

Because i'm not an iOS developer, i didn't immediately understand the specifics of building libraries through make for this platform.
The problem was this:
-miphoneos-version-min specifies the deployment target for iOS, but since i am building library for the iOS simulator, me need to use -mios-simulator-version-min.
As a result, the configuration command should look like this:
./Configure iossimulator-xcrun threads no-shared "-fvisibility=hidden -mios-simulator-version-min=9.0 -fembed-bitcode -fPIC" no-asm no-hw no-async --prefix=/Users/macosuser/Build/OpenSSL/Install "-arch arm64" "-isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator14.5.sdk"
If anyone can explain why the -miphoneos-version-min flag works as expected for i386 and x86_64 architectures, i would be grateful.