sys/libc: model Kconfig

sys/Kconfig

@@ -30,13 +30,34 @@ rsource "frac/Kconfig"
 rsource "hashes/Kconfig"
 rsource "iolist/Kconfig"
 rsource "isrpipe/Kconfig"
+
+menu "Libc"
+
+choice LIBC_IMPLEMENTATION
+    bool "Libc implementation"
+    depends on TEST_KCONFIG
+
+config MODULE_NEWLIB
+    bool "NewLib"
+    depends on HAS_NEWLIB
+
+config MODULE_PICOLIBC
+    bool "Picolibc"
+    depends on HAS_PICOLIBC
+
+endchoice
+
+rsource "Kconfig.newlib"
+rsource "Kconfig.picolibc"
+
+endmenu # Libc
+
 rsource "luid/Kconfig"
 rsource "malloc_thread_safe/Kconfig"
 rsource "matstat/Kconfig"
 rsource "memarray/Kconfig"
 rsource "mineplex/Kconfig"
 rsource "net/Kconfig"
-rsource "Kconfig.newlib"
 rsource "Kconfig.stdio"
 rsource "od/Kconfig"
 rsource "posix/Kconfig"

sys/Kconfig.newlib

@@ -5,10 +5,6 @@
 # directory for more details.
 #
 
-menuconfig MODULE_NEWLIB
-    bool "NewLib"
-    depends on TEST_KCONFIG
-
 if MODULE_NEWLIB
 
 config MODULE_NEWLIB_NANO
@@ -18,9 +14,11 @@ config MODULE_NEWLIB_GNU_SOURCE
     bool "NewLib GNU source"
 
 config MODULE_NEWLIB_SYSCALLS_DEFAULT
-    bool "NewLib Syscalls default implementation"
+    bool
     default y
     depends on !HAVE_CUSTOM_NEWLIB_SYSCALLS
+    help
+        Default implementation of newlib system calls.
 
 endif # MODULE_NEWLIB
 

sys/Kconfig.picolibc

@@ -0,0 +1,29 @@
+# Copyright (c) 2021 HAW Hamburg
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+#
+
+if MODULE_PICOLIBC
+
+config PICOLIBC_STDOUT_BUFFERED
+    bool "Buffered standard output"
+    default USE_STDOUT_BUFFERED
+    help
+        Say y to use buffering in the standard output, usually good for modules that benefit from
+        sending out buffers in larger chunks.
+
+config MODULE_PICOLIBC_SYSCALLS_DEFAULT
+    bool
+    default y
+    depends on !HAVE_CUSTOM_PICOLIBC_SYSCALLS
+    help
+        Default implementation of picolibc system calls.
+
+endif # MODULE_PICOLIBC
+
+config HAVE_CUSTOM_PICOLIB_SYSCALLS
+    bool
+    help
+        Indicates that a custom picolibc syscalls implementation is present.

sys/Kconfig.stdio

@@ -18,6 +18,7 @@ choice
 config MODULE_SLIPDEV_STDIO
     bool "SLIP network device"
     depends on MODULE_SLIPDEV
+    select USE_STDOUT_BUFFERED
     select MODULE_ISRPIPE
 
 config MODULE_STDIO_NULL
@@ -50,4 +51,9 @@ config MODULE_STDIO_UART_RX
 config MODULE_PRINTF_FLOAT
     bool "Float support in printf"
 
+config USE_STDOUT_BUFFERED
+    bool
+    help
+        Select this to prefer buffered standard output if provided by the implementation.
+
 endmenu # Standard Input/Output (STDIO)