diff --git a/bsp/es32f0334/rtconfig.py b/bsp/es32f0334/rtconfig.py
index f8be8244569e1cf63c6694e222f1b44447f1c891..170bae8a7be6e9c997fcc5e5a10e7de3ff2e021c 100644
--- a/bsp/es32f0334/rtconfig.py
+++ b/bsp/es32f0334/rtconfig.py
@@ -44,7 +44,7 @@ if PLATFORM == 'gcc':
     OBJDUMP = PREFIX + 'objdump'
     OBJCPY = PREFIX + 'objcopy'
     DEVICE = ' -mcpu=' + CPU + ' -mthumb -ffunction-sections -fdata-sections'
-    CFLAGS = DEVICE + ' -std=c99'
+    CFLAGS = DEVICE
     AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -Wa,-mimplicit-it=thumb'
     LFLAGS = DEVICE + ' -Wl,--gc-sections,-Map=rtthread.map,-cref,-u,Reset_Handler -T board/linker_scripts/link.lds'
 
diff --git a/bsp/es32f0654/rtconfig.py b/bsp/es32f0654/rtconfig.py
index f8be8244569e1cf63c6694e222f1b44447f1c891..170bae8a7be6e9c997fcc5e5a10e7de3ff2e021c 100644
--- a/bsp/es32f0654/rtconfig.py
+++ b/bsp/es32f0654/rtconfig.py
@@ -44,7 +44,7 @@ if PLATFORM == 'gcc':
     OBJDUMP = PREFIX + 'objdump'
     OBJCPY = PREFIX + 'objcopy'
     DEVICE = ' -mcpu=' + CPU + ' -mthumb -ffunction-sections -fdata-sections'
-    CFLAGS = DEVICE + ' -std=c99'
+    CFLAGS = DEVICE
     AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -Wa,-mimplicit-it=thumb'
     LFLAGS = DEVICE + ' -Wl,--gc-sections,-Map=rtthread.map,-cref,-u,Reset_Handler -T board/linker_scripts/link.lds'
 
diff --git a/bsp/gd32303e-eval/rtconfig.py b/bsp/gd32303e-eval/rtconfig.py
index d820325bee54c68bd6b7c85301a935e13e8d6918..c631bc3e443f71d25d77c4937be777f3959f115f 100644
--- a/bsp/gd32303e-eval/rtconfig.py
+++ b/bsp/gd32303e-eval/rtconfig.py
@@ -38,7 +38,7 @@ if PLATFORM == 'gcc':
     OBJCPY = PREFIX + 'objcopy'
 	
     DEVICE = ' -mcpu=cortex-m4 -mthumb -ffunction-sections -fdata-sections'
-    CFLAGS = DEVICE + ' -std=c99 -Dgcc' # -D' + PART_TYPE
+    CFLAGS = DEVICE + ' -Dgcc' # -D' + PART_TYPE
     AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -Wa,-mimplicit-it=thumb '
     LFLAGS = DEVICE + ' -Wl,--gc-sections,-Map=rtthread-gd32.map,-cref,-u,Reset_Handler -T gd32_rom.ld'
 
diff --git a/bsp/gd32450z-eval/rtconfig.py b/bsp/gd32450z-eval/rtconfig.py
index 4581630b0f2f9ee2daa18227f5a5c7ec798855ae..f137cf5a657ee6898f47e451237f0242944edead 100644
--- a/bsp/gd32450z-eval/rtconfig.py
+++ b/bsp/gd32450z-eval/rtconfig.py
@@ -39,7 +39,7 @@ if PLATFORM == 'gcc':
     OBJCPY = PREFIX + 'objcopy'
 	
     DEVICE = ' -mcpu=cortex-m4 -mthumb -mfpu=fpv4-sp-d16 -mfloat-abi=hard -ffunction-sections -fdata-sections'
-    CFLAGS = DEVICE + ' -std=c99 -Dgcc' # -D' + PART_TYPE
+    CFLAGS = DEVICE + ' -Dgcc' # -D' + PART_TYPE
     AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -Wa,-mimplicit-it=thumb '
     LFLAGS = DEVICE + ' -Wl,--gc-sections,-Map=rtthread-gd32.map,-cref,-u,Reset_Handler -T gd32_rom.ld'
 
diff --git a/bsp/imxrt/imxrt1021-evk/rtconfig.py b/bsp/imxrt/imxrt1021-evk/rtconfig.py
index b236dd652d4e55bfeb582593dd2396aec86ce232..f5a31f5463c1d92e5e2700f665fc5c8cba9c5832 100644
--- a/bsp/imxrt/imxrt1021-evk/rtconfig.py
+++ b/bsp/imxrt/imxrt1021-evk/rtconfig.py
@@ -41,7 +41,7 @@ if PLATFORM == 'gcc':
     STRIP = PREFIX + 'strip'
 
     DEVICE = ' -mcpu=cortex-m7 -mthumb -mfpu=fpv4-sp-d16 -mfloat-abi=hard -ffunction-sections -fdata-sections'
-    CFLAGS = DEVICE + ' -std=c99 -Wall -D__FPU_PRESENT -eentry'
+    CFLAGS = DEVICE + ' -Wall -D__FPU_PRESENT -eentry'
     AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -Wa,-mimplicit-it=thumb -D__START=entry'
     LFLAGS = DEVICE + ' -lm -lgcc -lc' + ' -nostartfiles -Wl,--gc-sections,-Map=rtthread.map,-cref,-u,Reset_Handler -T flexspi_nor.ld'
 
diff --git a/bsp/imxrt/imxrt1050-ArchMix/rtconfig.py b/bsp/imxrt/imxrt1050-ArchMix/rtconfig.py
index 1b4257884f6b3397ab61f70be9cc3e86220a6b06..c2ce83e8c3b62bca1d8c52d04d62089f031a8b57 100644
--- a/bsp/imxrt/imxrt1050-ArchMix/rtconfig.py
+++ b/bsp/imxrt/imxrt1050-ArchMix/rtconfig.py
@@ -41,7 +41,7 @@ if PLATFORM == 'gcc':
     STRIP = PREFIX + 'strip'
 
     DEVICE = ' -mcpu=cortex-m7 -mthumb -mfpu=fpv4-sp-d16 -mfloat-abi=hard -ffunction-sections -fdata-sections'
-    CFLAGS = DEVICE + ' -std=c99 -Wall -D__FPU_PRESENT -eentry'
+    CFLAGS = DEVICE + ' -Wall -D__FPU_PRESENT -eentry'
     AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -Wa,-mimplicit-it=thumb -D__START=entry'
     LFLAGS = DEVICE + ' -lm -lgcc -lc' + ' -nostartfiles -Wl,--gc-sections,-Map=rtthread-imxrt-gcc.map,-cref,-u,Reset_Handler -T flexspi_nor.ld'
 
diff --git a/bsp/imxrt/imxrt1050-evk/rtconfig.py b/bsp/imxrt/imxrt1050-evk/rtconfig.py
index 1b4257884f6b3397ab61f70be9cc3e86220a6b06..c2ce83e8c3b62bca1d8c52d04d62089f031a8b57 100644
--- a/bsp/imxrt/imxrt1050-evk/rtconfig.py
+++ b/bsp/imxrt/imxrt1050-evk/rtconfig.py
@@ -41,7 +41,7 @@ if PLATFORM == 'gcc':
     STRIP = PREFIX + 'strip'
 
     DEVICE = ' -mcpu=cortex-m7 -mthumb -mfpu=fpv4-sp-d16 -mfloat-abi=hard -ffunction-sections -fdata-sections'
-    CFLAGS = DEVICE + ' -std=c99 -Wall -D__FPU_PRESENT -eentry'
+    CFLAGS = DEVICE + ' -Wall -D__FPU_PRESENT -eentry'
     AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -Wa,-mimplicit-it=thumb -D__START=entry'
     LFLAGS = DEVICE + ' -lm -lgcc -lc' + ' -nostartfiles -Wl,--gc-sections,-Map=rtthread-imxrt-gcc.map,-cref,-u,Reset_Handler -T flexspi_nor.ld'
 
diff --git a/bsp/stm32/libraries/templates/stm32f0xx/rtconfig.py b/bsp/stm32/libraries/templates/stm32f0xx/rtconfig.py
index 3c8992f7d01582ecc40216354adbb9fabafdd849..bbc6a35774c768d3336f2b912adbb2136c186a78 100644
--- a/bsp/stm32/libraries/templates/stm32f0xx/rtconfig.py
+++ b/bsp/stm32/libraries/templates/stm32f0xx/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/libraries/templates/stm32f10x/rtconfig.py b/bsp/stm32/libraries/templates/stm32f10x/rtconfig.py
index c6d16622da8a2f0014ed8749ebd90a09ced91d69..fa46b74340f44e253167c1199793258783f0f469 100644
--- a/bsp/stm32/libraries/templates/stm32f10x/rtconfig.py
+++ b/bsp/stm32/libraries/templates/stm32f10x/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/libraries/templates/stm32f4xx/rtconfig.py b/bsp/stm32/libraries/templates/stm32f4xx/rtconfig.py
index 4a9fe33cef7faf24e59b8909c2de8d26d3da78eb..638f59502adefa10e239097d74adc9d4332fea92 100644
--- a/bsp/stm32/libraries/templates/stm32f4xx/rtconfig.py
+++ b/bsp/stm32/libraries/templates/stm32f4xx/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/libraries/templates/stm32f7xx/rtconfig.py b/bsp/stm32/libraries/templates/stm32f7xx/rtconfig.py
index 51fdf4d64a7d3339beefa9655d423f6cbbe0ba7f..74c4f9fee627ea8ac7884f401f9e51ed4b679ec2 100644
--- a/bsp/stm32/libraries/templates/stm32f7xx/rtconfig.py
+++ b/bsp/stm32/libraries/templates/stm32f7xx/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/libraries/templates/stm32l4xx/rtconfig.py b/bsp/stm32/libraries/templates/stm32l4xx/rtconfig.py
index ae800430f2c622c858cc3a84b10097d77b1efe0f..2e022a964bd2ef04dc5257b48b6d8e9e1ccb5f06 100644
--- a/bsp/stm32/libraries/templates/stm32l4xx/rtconfig.py
+++ b/bsp/stm32/libraries/templates/stm32l4xx/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f091-st-nucleo/rtconfig.py b/bsp/stm32/stm32f091-st-nucleo/rtconfig.py
index 3c8992f7d01582ecc40216354adbb9fabafdd849..bbc6a35774c768d3336f2b912adbb2136c186a78 100644
--- a/bsp/stm32/stm32f091-st-nucleo/rtconfig.py
+++ b/bsp/stm32/stm32f091-st-nucleo/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f103-atk-nano/rtconfig.py b/bsp/stm32/stm32f103-atk-nano/rtconfig.py
index 91aba6247859efa22ee160d54fa2fe6ade2ca528..9ace3b0a3c735bed7dada83bbbebaf22ed0f88f9 100644
--- a/bsp/stm32/stm32f103-atk-nano/rtconfig.py
+++ b/bsp/stm32/stm32f103-atk-nano/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f103-atk-warshipv3/rtconfig.py b/bsp/stm32/stm32f103-atk-warshipv3/rtconfig.py
index c6d16622da8a2f0014ed8749ebd90a09ced91d69..fa46b74340f44e253167c1199793258783f0f469 100644
--- a/bsp/stm32/stm32f103-atk-warshipv3/rtconfig.py
+++ b/bsp/stm32/stm32f103-atk-warshipv3/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f103-dofly-lyc8/rtconfig.py b/bsp/stm32/stm32f103-dofly-lyc8/rtconfig.py
index 91aba6247859efa22ee160d54fa2fe6ade2ca528..9ace3b0a3c735bed7dada83bbbebaf22ed0f88f9 100644
--- a/bsp/stm32/stm32f103-dofly-lyc8/rtconfig.py
+++ b/bsp/stm32/stm32f103-dofly-lyc8/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f103-fire-arbitrary/rtconfig.py b/bsp/stm32/stm32f103-fire-arbitrary/rtconfig.py
index 91aba6247859efa22ee160d54fa2fe6ade2ca528..9ace3b0a3c735bed7dada83bbbebaf22ed0f88f9 100644
--- a/bsp/stm32/stm32f103-fire-arbitrary/rtconfig.py
+++ b/bsp/stm32/stm32f103-fire-arbitrary/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f103-hw100k-ibox/rtconfig.py b/bsp/stm32/stm32f103-hw100k-ibox/rtconfig.py
index c6d16622da8a2f0014ed8749ebd90a09ced91d69..fa46b74340f44e253167c1199793258783f0f469 100644
--- a/bsp/stm32/stm32f103-hw100k-ibox/rtconfig.py
+++ b/bsp/stm32/stm32f103-hw100k-ibox/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f103-mini-system/rtconfig.py b/bsp/stm32/stm32f103-mini-system/rtconfig.py
index a839777aef5501292f9178cff8fd97afd8c38af5..c16c2fdda7d2b25bc4bc8a2f9b31a2ae32434f0c 100644
--- a/bsp/stm32/stm32f103-mini-system/rtconfig.py
+++ b/bsp/stm32/stm32f103-mini-system/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f107-uc-eval/rtconfig.py b/bsp/stm32/stm32f107-uc-eval/rtconfig.py
index 91aba6247859efa22ee160d54fa2fe6ade2ca528..9ace3b0a3c735bed7dada83bbbebaf22ed0f88f9 100644
--- a/bsp/stm32/stm32f107-uc-eval/rtconfig.py
+++ b/bsp/stm32/stm32f107-uc-eval/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f401-st-nucleo/rtconfig.py b/bsp/stm32/stm32f401-st-nucleo/rtconfig.py
index 3aafec60b86849c2ec39d8c3133a90c5b5d38d12..3b4b3a520840bcecb29f15a456278f3baa9eddb0 100644
--- a/bsp/stm32/stm32f401-st-nucleo/rtconfig.py
+++ b/bsp/stm32/stm32f401-st-nucleo/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f405-smdz-breadfruit/rtconfig.py b/bsp/stm32/stm32f405-smdz-breadfruit/rtconfig.py
index 5094363dfae61ea59ef3f412bc4b3f31ef3ad9a5..81e39f95132eefdb76fb41185277c2b390fa679b 100644
--- a/bsp/stm32/stm32f405-smdz-breadfruit/rtconfig.py
+++ b/bsp/stm32/stm32f405-smdz-breadfruit/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f407-atk-explorer/rtconfig.py b/bsp/stm32/stm32f407-atk-explorer/rtconfig.py
index 4a9fe33cef7faf24e59b8909c2de8d26d3da78eb..638f59502adefa10e239097d74adc9d4332fea92 100644
--- a/bsp/stm32/stm32f407-atk-explorer/rtconfig.py
+++ b/bsp/stm32/stm32f407-atk-explorer/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f407-st-discovery/rtconfig.py b/bsp/stm32/stm32f407-st-discovery/rtconfig.py
index 4f3dbc90ee68c1c08e4745547c48970e1dd659ec..32024fa83adbfc3c01a4bfcd9cbda61696690be3 100644
--- a/bsp/stm32/stm32f407-st-discovery/rtconfig.py
+++ b/bsp/stm32/stm32f407-st-discovery/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f411-st-nucleo/rtconfig.py b/bsp/stm32/stm32f411-st-nucleo/rtconfig.py
index 69a32c6da2364598b0fbefefeae7d15234e523cc..8c0a3e12816e7d8909d89ae1ca6400dc151650ca 100644
--- a/bsp/stm32/stm32f411-st-nucleo/rtconfig.py
+++ b/bsp/stm32/stm32f411-st-nucleo/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f429-armfly-v6/rtconfig.py b/bsp/stm32/stm32f429-armfly-v6/rtconfig.py
index 3bb974643b521ea260a84f98252eaeab04ac3dd3..79419c6c06be5a9c87a9d0d4b892c5a7dc6bb7f9 100644
--- a/bsp/stm32/stm32f429-armfly-v6/rtconfig.py
+++ b/bsp/stm32/stm32f429-armfly-v6/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f429-atk-apollo/rtconfig.py b/bsp/stm32/stm32f429-atk-apollo/rtconfig.py
index 4a9fe33cef7faf24e59b8909c2de8d26d3da78eb..638f59502adefa10e239097d74adc9d4332fea92 100644
--- a/bsp/stm32/stm32f429-atk-apollo/rtconfig.py
+++ b/bsp/stm32/stm32f429-atk-apollo/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f429-fire-challenger/rtconfig.py b/bsp/stm32/stm32f429-fire-challenger/rtconfig.py
index 4a9fe33cef7faf24e59b8909c2de8d26d3da78eb..638f59502adefa10e239097d74adc9d4332fea92 100644
--- a/bsp/stm32/stm32f429-fire-challenger/rtconfig.py
+++ b/bsp/stm32/stm32f429-fire-challenger/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f446-st-nucleo/rtconfig.py b/bsp/stm32/stm32f446-st-nucleo/rtconfig.py
index 4a9fe33cef7faf24e59b8909c2de8d26d3da78eb..638f59502adefa10e239097d74adc9d4332fea92 100644
--- a/bsp/stm32/stm32f446-st-nucleo/rtconfig.py
+++ b/bsp/stm32/stm32f446-st-nucleo/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f746-st-disco/rtconfig.py b/bsp/stm32/stm32f746-st-disco/rtconfig.py
index 4c4dc4ef021ba3e2cd163b04b177722f0afb1e20..0b3bfc1ac91b12f1f892239569041f2f40e4c3f1 100644
--- a/bsp/stm32/stm32f746-st-disco/rtconfig.py
+++ b/bsp/stm32/stm32f746-st-disco/rtconfig.py
@@ -57,7 +57,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2 -Os'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
     
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f767-atk-apollo/rtconfig.py b/bsp/stm32/stm32f767-atk-apollo/rtconfig.py
index 251d8168e79cfa667d1f99932eee4a3c8721b4d8..dedc1b9580d1d553bc5ab6d1d5394182ef8653e8 100644
--- a/bsp/stm32/stm32f767-atk-apollo/rtconfig.py
+++ b/bsp/stm32/stm32f767-atk-apollo/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f767-fire-challenger/rtconfig.py b/bsp/stm32/stm32f767-fire-challenger/rtconfig.py
index 93d7b660335085b9fff0cf8e5cf64832e5de5bca..7a46cc624d6acecc02044b675f348a5106a04095 100644
--- a/bsp/stm32/stm32f767-fire-challenger/rtconfig.py
+++ b/bsp/stm32/stm32f767-fire-challenger/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32f767-st-nucleo/rtconfig.py b/bsp/stm32/stm32f767-st-nucleo/rtconfig.py
index ef578d17cac2a1cb292d6dc8d2493a030009af48..ac2cda234b21e0fa63eaf5131f54e6566724574a 100644
--- a/bsp/stm32/stm32f767-st-nucleo/rtconfig.py
+++ b/bsp/stm32/stm32f767-st-nucleo/rtconfig.py
@@ -57,7 +57,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2 -Os'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32g071-st-nucleo/rtconfig.py b/bsp/stm32/stm32g071-st-nucleo/rtconfig.py
index 7b2a05c9e3ac15db6ce2d31eba54d621c53d7adc..d86774675de717c01e36f5c6d88cad28056a2882 100644
--- a/bsp/stm32/stm32g071-st-nucleo/rtconfig.py
+++ b/bsp/stm32/stm32g071-st-nucleo/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32l053-st-nucleo/rtconfig.py b/bsp/stm32/stm32l053-st-nucleo/rtconfig.py
index ff1b0664a58920040d1253651a4ecca95ca0ca99..39d6af68797f3d9d576a12e6c4127f6b1dc402b1 100644
--- a/bsp/stm32/stm32l053-st-nucleo/rtconfig.py
+++ b/bsp/stm32/stm32l053-st-nucleo/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
     
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32l432-st-nucleo/rtconfig.py b/bsp/stm32/stm32l432-st-nucleo/rtconfig.py
index ae800430f2c622c858cc3a84b10097d77b1efe0f..2e022a964bd2ef04dc5257b48b6d8e9e1ccb5f06 100644
--- a/bsp/stm32/stm32l432-st-nucleo/rtconfig.py
+++ b/bsp/stm32/stm32l432-st-nucleo/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32l475-atk-pandora/rtconfig.py b/bsp/stm32/stm32l475-atk-pandora/rtconfig.py
index 2b495647e4df4651ad367382c38618b61e4c4d57..40b84ad8465b1764de898817be5fa27c6852de2e 100644
--- a/bsp/stm32/stm32l475-atk-pandora/rtconfig.py
+++ b/bsp/stm32/stm32l475-atk-pandora/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32l475-st-discovery/rtconfig.py b/bsp/stm32/stm32l475-st-discovery/rtconfig.py
index 2876ce676183a7855a635646a21746d08fb8ad8f..3e4718a48271e274f66f067d1db5ff6de4b7a3d5 100644
--- a/bsp/stm32/stm32l475-st-discovery/rtconfig.py
+++ b/bsp/stm32/stm32l475-st-discovery/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32l476-st-nucleo/rtconfig.py b/bsp/stm32/stm32l476-st-nucleo/rtconfig.py
index f13d785d547a1d7cdda2663f7bd13e96acab2a03..7fc0f14860107eb851c6815cc77ad79d2b92b8d0 100644
--- a/bsp/stm32/stm32l476-st-nucleo/rtconfig.py
+++ b/bsp/stm32/stm32l476-st-nucleo/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32/stm32l496-ali-developer/rtconfig.py b/bsp/stm32/stm32l496-ali-developer/rtconfig.py
index ae800430f2c622c858cc3a84b10097d77b1efe0f..2e022a964bd2ef04dc5257b48b6d8e9e1ccb5f06 100644
--- a/bsp/stm32/stm32l496-ali-developer/rtconfig.py
+++ b/bsp/stm32/stm32l496-ali-developer/rtconfig.py
@@ -58,7 +58,6 @@ if PLATFORM == 'gcc':
         CFLAGS += ' -O2'
 
     CXXFLAGS = CFLAGS 
-    CFLAGS += ' -std=c99'
 
     POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
 
diff --git a/bsp/stm32f4xx-HAL/rtconfig.py b/bsp/stm32f4xx-HAL/rtconfig.py
index 39d157a9dcbfed17444900811ec12ad033170203..7dfb083d1a02e644e8a372b52684a71c2215ee01 100644
--- a/bsp/stm32f4xx-HAL/rtconfig.py
+++ b/bsp/stm32f4xx-HAL/rtconfig.py
@@ -43,7 +43,7 @@ if PLATFORM == 'gcc':
     OBJCPY = PREFIX + 'objcopy'
 	
     DEVICE = ' -mcpu=cortex-m4 -mthumb -mfpu=fpv4-sp-d16 -mfloat-abi=hard -ffunction-sections -fdata-sections'
-    CFLAGS = DEVICE + ' -std=c99'
+    CFLAGS = DEVICE
     AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -Wa,-mimplicit-it=thumb '
     LFLAGS = DEVICE + ' -Wl,--gc-sections,-Map=rtthread-stm32.map,-cref,-u,Reset_Handler -T stm32_rom.ld'
 
diff --git a/bsp/swm320-lq100/rtconfig.py b/bsp/swm320-lq100/rtconfig.py
index c8f9102c768fedb2ec1015771e98ca0d4448ddb4..7d827e2ab2ee4395acbd7de289134585152cd846 100644
--- a/bsp/swm320-lq100/rtconfig.py
+++ b/bsp/swm320-lq100/rtconfig.py
@@ -45,7 +45,7 @@ if PLATFORM == 'gcc':
 
     DEVICE = ' -mcpu=' + CPU + ' -mthumb -mfpu=' + FPU + ' -mfloat-abi=' + \
         FLOAT_ABI + ' -ffunction-sections -fdata-sections'
-    CFLAGS = DEVICE + ' -std=c99'
+    CFLAGS = DEVICE
     AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -Wa,-mimplicit-it=thumb '
     LFLAGS = DEVICE + ' -Wl,--gc-sections,-Map=rtthread.map,-cref,-u,Reset_Handler -T drivers/linker_scripts/link.lds'
 
diff --git a/bsp/tm4c129x/rtconfig.py b/bsp/tm4c129x/rtconfig.py
index 8db01c509b8973742f1964146e2a4cd50b263fe7..691d51358b61c6c5f1945815b33868d61a063c7c 100644
--- a/bsp/tm4c129x/rtconfig.py
+++ b/bsp/tm4c129x/rtconfig.py
@@ -43,7 +43,7 @@ if PLATFORM == 'gcc':
     OBJCPY = PREFIX + 'objcopy'
     
     DEVICE = ' -mcpu=cortex-m4 -mthumb -mfpu=fpv4-sp-d16 -mfloat-abi=softfp -ffunction-sections -fdata-sections'
-    CFLAGS = DEVICE + ' -std=c99 -Dgcc'
+    CFLAGS = DEVICE + ' -Dgcc'
     AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -Wa,-mimplicit-it=thumb '
     LFLAGS = DEVICE + ' -Wl,--gc-sections,-Map=rtthread-tm4c129x.map,-cref,-u,Reset_Handler -T tm4c_rom.ld'