[libc][musl] support arm-linux-musleabi toolchain

目前基本功能已经可以在QEMU上跑起来，但是pthread和内核signal选中会报冲突。先合并一版本，后续解决这些问题。

bsp/qemu-vexpress-a9/rtconfig.py

@@ -1,8 +1,8 @@
 import os
 
 import uuid
-def get_mac_address(): 
-    mac=uuid.UUID(int = uuid.getnode()).hex[-12:] 
+def get_mac_address():
+    mac=uuid.UUID(int = uuid.getnode()).hex[-12:]
     return "#define AUTOMAC".join([str(int(e/2) + 1) + '  0x' + mac[e:e+2] + '\n' for e in range(5,11,2)])
 
 header = '''
@@ -26,56 +26,45 @@ with open(automac_h_fn, 'w') as f:
     f.write(header + get_mac_address() + end)
 
 # toolchains options
-ARCH='arm'
-CPU='cortex-a'
-CROSS_TOOL='gcc'
-
-if os.getenv('RTT_CC'):
-    CROSS_TOOL = os.getenv('RTT_CC')
-
-# only support GNU GCC compiler.
+ARCH        ='arm'
+CPU         ='cortex-a'
+CROSS_TOOL  = 'gcc'
 PLATFORM    = 'gcc'
-EXEC_PATH   = r'/usr/bin'
-
-if os.getenv('RTT_EXEC_PATH'):
-    EXEC_PATH = os.getenv('RTT_EXEC_PATH')
-
-BUILD = 'debug'
+EXEC_PATH   = os.getenv('RTT_EXEC_PATH') or r'/usr/bin'
+BUILD       = 'debug'
 
 if PLATFORM == 'gcc':
     # toolchains
-    PREFIX = 'arm-none-eabi-'
-    CC = PREFIX + 'gcc'
-    CXX = PREFIX + 'g++'
-    AS = PREFIX + 'gcc'
-    AR = PREFIX + 'ar'
-    LINK = PREFIX + 'gcc'
+    PREFIX  = os.getenv('RTT_CC_PREFIX') or 'arm-none-eabi-'
+    CC      = PREFIX + 'gcc'
+    CXX     = PREFIX + 'g++'
+    AS      = PREFIX + 'gcc'
+    AR      = PREFIX + 'ar'
+    LINK    = PREFIX + 'gcc'
     TARGET_EXT = 'elf'
-    SIZE = PREFIX + 'size'
+    SIZE    = PREFIX + 'size'
     OBJDUMP = PREFIX + 'objdump'
-    OBJCPY = PREFIX + 'objcopy'
-    STRIP = PREFIX + 'strip'
+    OBJCPY  = PREFIX + 'objcopy'
+    STRIP   = PREFIX + 'strip'
+    CFPFLAGS = ' -msoft-float'
+    AFPFLAGS = ' -mfloat-abi=softfp -mfpu=neon'
+    DEVICE   = ' -march=armv7-a -mtune=cortex-a7 -ftree-vectorize -ffast-math -funwind-tables -fno-strict-aliasing'
 
-    DEVICE = ' -march=armv7-a -marm -msoft-float'
-    CFLAGS = DEVICE + ' -Wall -Werror'
-    AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -D__ASSEMBLY__ -I.'
-    LINK_SCRIPT = 'link.lds'
-    LFLAGS = DEVICE + ' -nostartfiles -Wl,--gc-sections,-Map=rtthread.map,-cref,-u,system_vectors'+\
-                      ' -T %s' % LINK_SCRIPT
-
-    CPATH = ''
-    LPATH = ''
-
-    # generate debug info in all cases
-    AFLAGS += ' -gdwarf-2'
-    CFLAGS += ' -g -gdwarf-2'
+    CXXFLAGS= DEVICE + CFPFLAGS + ' -Wall'
+    CFLAGS  = DEVICE + CFPFLAGS + ' -Wall -std=gnu99'
+    AFLAGS  = DEVICE + ' -c' + AFPFLAGS + ' -x assembler-with-cpp'
+    LFLAGS  = DEVICE + ' -Wl,--gc-sections,-Map=rtthread.map,-cref,-u,system_vectors -T link.lds' + ' -lsupc++ -lgcc -static'
+    CPATH   = ''
+    LPATH   = ''
 
     if BUILD == 'debug':
-        CFLAGS += ' -O0'
+        CFLAGS   += ' -O0 -gdwarf-2'
+        CXXFLAGS += ' -O0 -gdwarf-2'
+        AFLAGS   += ' -gdwarf-2'
     else:
-        CFLAGS += ' -O2'
-
-    CXXFLAGS = CFLAGS + ' -Woverloaded-virtual -fno-exceptions -fno-rtti'
+        CFLAGS   += ' -Os'
+        CXXFLAGS += ' -Os'
+    CXXFLAGS += ' -Woverloaded-virtual -fno-exceptions -fno-rtti'
 
     M_CFLAGS = CFLAGS + ' -mlong-calls -fPIC '
     M_CXXFLAGS = CXXFLAGS + ' -mlong-calls -fPIC'
@@ -83,5 +72,6 @@ if PLATFORM == 'gcc':
                                     ' -shared -fPIC -nostartfiles -nostdlib -static-libgcc'
     M_POST_ACTION = STRIP + ' -R .hash $TARGET\n' + SIZE + ' $TARGET \n'
 
+    DUMP_ACTION = OBJDUMP + ' -D -S $TARGET > rtt.asm\n'
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' +\
                   SIZE + ' $TARGET \n'