Disable unaligned access (may not work across armv6-v8 on same binary)

src/armc-start.S

@@ -441,7 +441,7 @@ _swi_handler_:
 _enable_unaligned_access:
     mrc      p15, 0, r0, c1, c0, 0   // read SCTLR
     bic      r0, r0, #2              // A (no unaligned access fault)
-    orr      r0, r0, #1 << 22        // U (v6 unaligned access model)
+    orr      r0, r0, #1 << 22        // U (v6 unaligned access model) not available on arm v8
     mcr      p15, 0, r0, c1, c0, 0   // write SCTLR
     mov      pc, lr
 

src/rgb_to_fb.S

@@ -2281,7 +2281,7 @@ run_core:
         mov r0, 0
         mov r1, 0
         bl     enable_MMU_and_IDCaches
-        bl    _enable_unaligned_access
+    //    bl    _enable_unaligned_access  //do not use for an armv6 to armv8 compatible binary
         bl    _init_cycle_counter
 run_core_loop:
         wfe

src/rgb_to_hdmi.c

@@ -3584,7 +3584,7 @@ void kernel_main(unsigned int r0, unsigned int r1, unsigned int atags)
 #else
     enable_MMU_and_IDCaches(0,0);
 #endif
-    _enable_unaligned_access();
+    //_enable_unaligned_access();  //do not use for an armv6 to armv8 compatible binary
 
     log_info("***********************RESET***********************");
     log_info("RGB to HDMI booted");

src/toolchain-arm-none-eabi-rpi.cmake

@@ -59,6 +59,7 @@ set( CMAKE_OBJCOPY      ${TC_PATH}${CROSS_COMPILE}objcopy
 
 #use hardware floating point
 set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfloat-abi=hard" )
+set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mno-unaligned-access" )
 
 #pi1 flags
 #set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=armv6zk" )

src/toolchain-arm-none-eabi-rpi4.cmake

@@ -59,6 +59,7 @@ set( CMAKE_OBJCOPY      ${TC_PATH}${CROSS_COMPILE}objcopy
 
 #use hardware floating point
 set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfloat-abi=hard" )
+set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mno-unaligned-access" )
 
 #pi1 flags
 #set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=armv6zk" )
@@ -75,10 +76,15 @@ set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfloat-abi=hard" )
 #set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mtune=cortex-a53" )
 #set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfpu=crypto-neon-fp-armv8" )
 
-#current flags for all
-set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=armv6zk" )
-set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mtune=arm1176jzf-s" )
-set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfpu=vfp" )
+#pi4 flags
+#set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=armv8-a" )
+#set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mtune=cortex-a72" )
+#set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfpu=crypto-neon-fp-armv8" )
+
+#current flags
+set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=armv8-a" )
+set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mtune=cortex-a72" )
+set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfpu=crypto-neon-fp-armv8" )
 set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS}" CACHE STRING "" )
 
 set( CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} -march=armv7-a" )

src/toolchain-arm-none-eabi-rpiA.cmake

@@ -59,6 +59,7 @@ set( CMAKE_OBJCOPY      ${TC_PATH}${CROSS_COMPILE}objcopy
 
 #use hardware floating point
 set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfloat-abi=hard" )
+set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mno-unaligned-access" )
 
 #pi1 flags
 #set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=armv6zk" )

src/toolchain-arm-none-eabi-rpiA4.cmake

@@ -59,6 +59,7 @@ set( CMAKE_OBJCOPY      ${TC_PATH}${CROSS_COMPILE}objcopy
 
 #use hardware floating point
 set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfloat-abi=hard" )
+set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mno-unaligned-access" )
 
 #pi1 flags
 #set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=armv6zk" )
@@ -75,10 +76,15 @@ set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfloat-abi=hard" )
 #set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mtune=cortex-a53" )
 #set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfpu=crypto-neon-fp-armv8" )
 
-#current flags for all
-set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=armv6zk" )
-set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mtune=arm1176jzf-s" )
-set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfpu=vfp" )
+#pi4 flags
+#set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=armv8-a" )
+#set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mtune=cortex-a72" )
+#set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfpu=crypto-neon-fp-armv8" )
+
+#current flags
+set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -march=armv8-a" )
+set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mtune=cortex-a72" )
+set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfpu=crypto-neon-fp-armv8" )
 set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS}" CACHE STRING "" )
 
 set( CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} -march=armv7-a" )