From b4207b3fd9704c4543e08e8bfc932fe95542fc8c Mon Sep 17 00:00:00 2001
From: fgsfds <derp.primus@gmail.com>
Date: Sun, 20 Aug 2023 21:40:44 +0200
Subject: [PATCH] port: allow theoretical ARM builds

this requires your device to support desktop GL3+ and might require manual setting of the TOOLCHAIN variable
---
 Makefile.port          | 10 ++++++++--
 src/include/platform.h | 26 ++++++++++++++++++--------
 2 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/Makefile.port b/Makefile.port
index bd1a6f998..eb33847a1 100644
--- a/Makefile.port
+++ b/Makefile.port
@@ -132,10 +132,16 @@ ifneq (,$(findstring windows,$(TARGET_PLATFORM)))
   TARGET_CFLAGS := $(shell pkg-config sdl2 --cflags-only-I)
   TARGET_LDFLAGS := $(shell pkg-config sdl2 --libs) -lz -lopengl32 -static-libstdc++
   # on windows/mingw we need this to be built with a 32-bit compiler so it finds the correct libs
-  TOOLCHAIN := i686-w64-mingw32-
-else # TODO
+  TOOLCHAIN ?= i686-w64-mingw32-
+else # assume *nix
   TARGET_CFLAGS := $(shell pkg-config sdl2 --cflags-only-I)
   TARGET_LDFLAGS := $(shell pkg-config sdl2 --libs) -lGL -lz
+  ifneq (,$(findstring arm,$(TARGET_PLATFORM))$(findstring aarch,$(TARGET_PLATFORM)))
+    # linux on arm or aarch64
+    # TODO: detect soft/hardfloat abi
+    TARGET_LDFLAGS += -ldl
+    TOOLCHAIN ?= arm-linux-gnueabihf-
+  endif
 endif
 
 # On x86_64 gcc add -m32 to CFLAGS if building a 32-bit executable.
diff --git a/src/include/platform.h b/src/include/platform.h
index b77f09e81..7542a6815 100644
--- a/src/include/platform.h
+++ b/src/include/platform.h
@@ -4,14 +4,13 @@
 // detect OS
 #if defined(_WIN32)
 	#define PLATFORM_WIN32 1
-#else
-	// assume POSIX compatible
+#elif defined(__linux__)
 	#define PLATFORM_POSIX 1
-	#if defined(__linux__)
-		#define PLATFORM_LINUX 1
-	#else // TODO
-		#error "Unknown platform."
-	#endif
+	#define PLATFORM_LINUX 1
+#else
+	// assume POSIX-compatible
+	#define PLATFORM_POSIX 1
+	#warning "Unknown OS. Please add it to platform.h."
 #endif
 
 // detect arch
@@ -20,10 +19,21 @@
 	#define PLATFORM_64BIT 1
 #elif defined(__i386__) || defined(_X86_) || defined(_M_IX86)
 	#define PLATFORM_X86 1
-#else // TODO
+#elif defined(__aarch64__) || defined(_M_ARM64)
+	#define PLATFORM_ARM 8
+	#define PLATFORM_64BIT 1
+#elif defined(__arm__) || defined(_M_ARM)
+	// assume armv7
+	#define PLATFORM_ARM 7
+#else
 	#error "Unknown CPU arch."
 #endif
 
+// TODO: remove this after 64-bit support is in place
+#ifdef PLATFORM_64BIT
+	#error "64-bit platforms are currently not supported."
+#endif
+
 // detect endianness
 #if defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__)
 	#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__