[bsp] stm32/stm32f407-atk-explorer add LLVM for Arm support.

bsp/stm32/stm32f407-atk-explorer/board/SConscript

@@ -32,7 +32,7 @@ path += [cwd + '/ports']
 
 startup_path_prefix = SDK_LIB
 
-if rtconfig.CROSS_TOOL == 'gcc':
+if rtconfig.CROSS_TOOL == 'gcc' or rtconfig.CROSS_TOOL == 'clang':
     src += [startup_path_prefix + '/STM32F4xx_HAL/CMSIS/Device/ST/STM32F4xx/Source/Templates/gcc/startup_stm32f407xx.s']
 elif rtconfig.CROSS_TOOL == 'keil':
     src += [startup_path_prefix + '/STM32F4xx_HAL/CMSIS/Device/ST/STM32F4xx/Source/Templates/arm/startup_stm32f407xx.s']

bsp/stm32/stm32f407-atk-explorer/board/linker_scripts/link.lds

@@ -48,6 +48,9 @@ SECTIONS
         KEEP(*(SORT(.rti_fn*)))
         __rt_init_end = .;
 
+        . = ALIGN(4);
+        KEEP(*(FalPartTable))
+
         . = ALIGN(4);
 
         PROVIDE(__ctors_start__ = .);

bsp/stm32/stm32f407-atk-explorer/rtconfig.py

@@ -24,6 +24,9 @@
 elif CROSS_TOOL == 'iar':
     PLATFORM    = 'iar'
     EXEC_PATH   = r'C:/Program Files (x86)/IAR Systems/Embedded Workbench 8.0'
+elif CROSS_TOOL == 'clang':
+    PLATFORM    = 'clang'
+    EXEC_PATH   = r'/opt/LLVMEmbeddedToolchainForArm-13.0.0/bin'
 
 if os.getenv('RTT_EXEC_PATH'):
     EXEC_PATH = os.getenv('RTT_EXEC_PATH')
@@ -176,6 +179,38 @@
     EXEC_PATH = EXEC_PATH + '/arm/bin/'
     POST_ACTION = 'ielftool --bin $TARGET rtthread.bin'
 
+elif PLATFORM == 'clang':
+    # toolchains
+    PREFIX = 'llvm-'
+    CC = 'clang'
+    AS = 'clang'
+    AR = PREFIX + 'ar'
+    CXX = 'clang++'
+    LINK = 'clang'
+    TARGET_EXT = 'elf'
+    SIZE = PREFIX + 'size'
+    OBJDUMP = PREFIX + 'objdump'
+    OBJCPY = PREFIX + 'objcopy'
+
+    DEVICE = ' --config armv7em_hard_fpv4_sp_d16_nosys -ffunction-sections -fdata-sections'
+    CFLAGS = DEVICE
+    AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -Wa,-mimplicit-it=thumb '
+    LFLAGS = DEVICE + ' -Wl,--gc-sections,-Map=rt-thread.map,-u,Reset_Handler -T board/linker_scripts/link.lds'
+
+    CPATH = ''
+    LPATH = ''
+
+    if BUILD == 'debug':
+        CFLAGS += ' -O0 -gdwarf-2 -g'
+        AFLAGS += ' -gdwarf-2'
+    else:
+        CFLAGS += ' -O2'
+
+    CXXFLAGS = CFLAGS 
+
+    POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
+
+
 def dist_handle(BSP_ROOT, dist_dir):
     import sys
     cwd_path = os.getcwd()

components/libc/compilers/gcc/partial/mips/SConscript

@@ -8,7 +8,7 @@ cwd   = GetCurrentDir()
 CPPPATH = [cwd]
 group = []
 
-if rtconfig.PLATFORM == 'gcc' and ('mips' in rtconfig.PREFIX): # identify mips gcc tool chain
+if (rtconfig.PLATFORM == 'gcc' and ('mips' in rtconfig.PREFIX)) or rtconfig.PLATFORM == 'clang': # identify mips gcc tool chain
     try:
         # There is no 'sys/select.h' in tthe mips gcc toolchain; it will be copied from 'nogcc/sys/select.h'
         copy("../../../common/nogcc/sys/select.h", "./sys/select.h")

components/libc/compilers/gcc/partial/mips/sys/select.h

@@ -15,6 +15,10 @@
 #include <sys/types.h>
 #include <sys/time.h>
 
+#ifdef _WIN32
+#include <winsock.h>
+#endif
+
 #ifndef  FD_SETSIZE
 #define  FD_SETSIZE  32
 #endif
@@ -26,16 +30,17 @@
 #define FD_SETSIZE      DFS_FD_MAX
 #endif /* SAL_USING_POSIX */
 
-#define   NBBY    8       /* number of bits in a byte */
-
 typedef long    fd_mask;
 
+#ifndef _WIN32
+#ifndef _SYS_TYPES_FD_SET /* MIPS */
+
+#define   NBBY    8       /* number of bits in a byte */
 #define   NFDBITS (sizeof (fd_mask) * NBBY)   /* bits per mask */
 #ifndef   howmany
 #define   howmany(x,y)    (((x)+((y)-1))/(y))
 #endif
 
-#ifndef _SYS_TYPES_FD_SET /* MIPS */
 typedef struct _types_fd_set {
     fd_mask fds_bits[howmany(FD_SETSIZE, NFDBITS)];
 } _types_fd_set;
@@ -48,5 +53,6 @@ typedef struct _types_fd_set {
 #endif /* _SYS_TYPES_FD_SET */
 
 int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout);
+#endif /* _WIN32 */
 
 #endif /* __SYS_SELECT_H__ */