6 files changed, 57 insertions, 2 deletions
diff --git a/components/drivers/spi/SConscript b/components/drivers/spi/SConscript
index 27b7a8dd71..e84ed7bb06 100644
--- a/components/drivers/spi/SConscript
+++ b/components/drivers/spi/SConscript
@@ -29,7 +29,7 @@ if GetDepend('RT_USING_SFUD'):
     if GetDepend('RT_SFUD_USING_SFDP'):
         src_device += ['sfud/src/sfud_sfdp.c']
 
-    if rtconfig.PLATFORM in ['gcc', 'armclang']:
+    if rtconfig.PLATFORM in ['gcc', 'armclang', 'llvm-arm']:
         LOCAL_CFLAGS += ' -std=c99'
     elif rtconfig.PLATFORM in ['armcc']:
         LOCAL_CFLAGS += ' --c99'
diff --git a/components/libc/compilers/common/cstring.c b/components/libc/compilers/common/cstring.c
index 733433598e..59c516d273 100644
--- a/components/libc/compilers/common/cstring.c
+++ b/components/libc/compilers/common/cstring.c
@@ -19,10 +19,12 @@
  *
  * @note  The bzero() function is deprecated (marked as LEGACY in POSIX. 1-2001).
  */
+#ifndef RT_USING_PICOLIBC
 void bzero(void* s, size_t n)
 {
     rt_memset(s, 0, n);
 }
+#endif
 
 void bcopy(const void* src, void* dest, size_t n)
 {
diff --git a/components/libc/compilers/common/extension/SConscript b/components/libc/compilers/common/extension/SConscript
index ddd83c8234..75bb23d18e 100644
--- a/components/libc/compilers/common/extension/SConscript
+++ b/components/libc/compilers/common/extension/SConscript
@@ -9,7 +9,7 @@ group = []
 
 src += Glob('*.c')
 
-if rtconfig.PLATFORM != 'gcc':
+if rtconfig.PLATFORM != 'gcc' and rtconfig.PLATFORM != 'llvm-arm':
     group = DefineGroup('Compiler', src, depend = [''], CPPPATH = CPPPATH)
 
 list = os.listdir(cwd)
diff --git a/components/libc/compilers/picolibc/README.md b/components/libc/compilers/picolibc/README.md
new file mode 100644
index 0000000000..af766e7ca7
--- /dev/null
+++ b/components/libc/compilers/picolibc/README.md
@@ -0,0 +1,8 @@
+# PICOLIBC (LLVM-ARM) porting for RT-Thread
+
+https://github.com/ARM-software/LLVM-embedded-toolchain-for-Arm
+
+https://github.com/picolibc/picolibc
+
+
+
diff --git a/components/libc/compilers/picolibc/SConscript b/components/libc/compilers/picolibc/SConscript
new file mode 100644
index 0000000000..999f7cca56
--- /dev/null
+++ b/components/libc/compilers/picolibc/SConscript
@@ -0,0 +1,29 @@
+import os
+from building import *
+from llvm_arm import *
+Import('rtconfig')
+
+group = []
+
+picolibc_version = GetPicoLibcVersion(rtconfig)
+
+if picolibc_version and not GetDepend('RT_USING_EXTERNAL_LIBC'):
+    print('PicoLibc version: ' + picolibc_version)
+
+    cwd = GetCurrentDir()
+    src = Glob('*.c')
+
+    CPPPATH = [cwd]
+    CPPDEFINES = ['RT_USING_PICOLIBC', 'RT_USING_LIBC', '_POSIX_C_SOURCE=1', '__PICOLIBC_ERRNO_FUNCTION=pico_get_errno'] # identify this is Newlib, and only enable POSIX.1-1990
+    # LIBS = ['c', 'm'] # link libc and libm
+    AddDepend(['RT_USING_PICOLIBC', 'RT_USING_LIBC'])
+
+    group = group + DefineGroup('Compiler', src, depend = [''], CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES)#, LIBS = LIBS)
+
+    list = os.listdir(cwd)
+    for d in list:
+        path = os.path.join(cwd, d)
+        if os.path.isfile(os.path.join(path, 'SConscript')):
+            group = group + SConscript(os.path.join(d, 'SConscript'))
+
+Return('group')
diff --git a/components/libc/compilers/picolibc/syscall.c b/components/libc/compilers/picolibc/syscall.c
new file mode 100644
index 0000000000..882964a1f3
--- /dev/null
+++ b/components/libc/compilers/picolibc/syscall.c
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2006-2023, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2023-05-17     Flybreak     the first version
+ */
+
+#include <rtthread.h>
+
+int pico_get_errno(void)
+{
+    return rt_get_errno();
+}