Merge branch 'keith-packard-picolibc' into master

config/configure.in.in

@@ -15,6 +15,12 @@ config CONFIGURE_has_wget
 config CONFIGURE_has_curl
     @KCONFIG_curl@
 
+config CONFIGURE_has_meson
+    @KCONFIG_meson@
+
+config CONFIGURE_has_ninja
+    @KCONFIG_ninja@
+
 config CONFIGURE_has_make_3_81_or_newer
     @KCONFIG_make_3_81_or_newer@
 

config/libc/picolibc.in

@@ -0,0 +1,124 @@
+# picolibc options
+
+## depends on BARE_METAL && CONFIGURE_has_meson && CONFIGURE_has_ninja
+## select LIBC_SUPPORT_THREADS_NATIVE
+
+## select CC_CORE_PASSES_NEEDED if CANADIAN
+## select CC_CORE_PASS_2_NEEDED if ! CANADIAN
+
+## help Picolibc is a C library intended for use on embedded systems. It is a
+## help conglomeration of several library parts, all under BSD-compatible software
+## help licenses that make them easily usable on embedded products. Picolibc
+## help is only available in source form. It can be compiled for a wide
+## help array of processors, and will usually work on any architecture with
+## help the addition of a few low-level routines.
+
+config PICOLIBC_CXA_ATEXIT
+    def_bool y
+    select LIBC_PROVIDES_CXA_ATEXIT
+
+config LIBC_PICOLIBC_TARGET_CFLAGS
+    string
+    prompt "Target CFLAGS for picolibc"
+    default ""
+    help
+      Used to add specific options when compiling the target libraries
+      (eg. -ffunction-sections -fdata-sections), which can't be defined
+      in global TARGET_CFLAGS, because they shall be not used for the
+      gcc target libraries.
+      Note:  Both TARGET_CFLAGS and LIBC_PICOLIBC_TARGET_CFLAGS are used
+             to compile the libraries.
+
+      Leave blank if you don't know better.
+
+config LIBC_PICOLIBC_IO_C99FMT
+    bool
+    prompt "Enable IOs on C99 formats"
+    default y
+    help
+      Enable support for IOs on C99 formats.
+
+config LIBC_PICOLIBC_REGISTER_FINI
+    bool
+    prompt "Enable finalization function registration using atexit"
+    help
+        Enable finalization function registration using atexit.
+
+config LIBC_PICOLIBC_ATEXIT_DYNAMIC_ALLOC
+    bool
+    prompt "Enable dynamic allocation of atexit entries"
+    help
+        Enable dynamic allocation of atexit entries.
+
+config LIBC_PICOLIBC_GLOBAL_ATEXIT
+    bool
+    prompt "Enable atexit data structure as global variable"
+    help
+        Enable atexit data structure as global variable, instead
+	of being thread-local.
+
+config LIBC_PICOLIBC_LITE_EXIT
+    bool
+    prompt "Enable lite exit"
+    default y
+    help
+        Enable lite exit, a size-reduced implementation of exit that doesn't
+        invoke clean-up functions such as _fini or global destructors.
+
+config LIBC_PICOLIBC_MULTITHREAD
+    bool
+    prompt "Enable support for multiple threads"
+    default y
+    help
+        Enable support for multiple threads.
+
+config LIBC_PICOLIBC_RETARGETABLE_LOCKING
+    bool
+    prompt "Enable retargetable locking"
+    help
+        Enable retargetable locking to allow the operating system to override
+        the dummy lock functions defined within picolibc.
+
+config LIBC_PICOLIBC_EXTRA_SECTIONS
+    bool
+    prompt "Place each function & data element in their own section"
+    help
+        Place each function & data symbol in their own section. This allows
+        the linker to garbage collect unused symbols at link time.
+
+config LIBC_PICOLIBC_ENABLE_TARGET_OPTSPACE
+    bool
+    prompt "Optimize picolibc for size"
+    default y
+    help
+      Pass --enable-target-optspace to picolibc configure.
+
+      This will compile picolibc with -Os.
+
+config LIBC_PICOLIBC_LTO
+    bool
+    prompt "Enable Link Time Optimization"
+    depends on CC_GCC_USE_LTO
+    help
+      Builds the libraries with -flto to enable more aggressive link time
+      optimization. You will need to add -flto-partition=one to your
+      application's link line to keep the RETURN assembler macro together
+      with it's consumers.
+
+config LIBC_PICOLIBC_NANO_MALLOC
+    bool
+    prompt "Enable Nano Malloc"
+    default y
+    help
+      PICOLIBC has two implementations of malloc family's functions, one in
+      `mallocr.c' and the other one in `nano-mallocr.c'.  This options
+      enables the nano-malloc implementation, which is for small systems
+      with very limited memory.  Note that this implementation does not
+      support `--enable-malloc-debugging' any more.
+
+config LIBC_PICOLIBC_EXTRA_CONFIG_ARRAY
+    string
+    prompt "Extra config for picolibc"
+    default ""
+    help
+      Extra flags to pass to meson when configuring picolibc.

configure.ac

@@ -152,6 +152,14 @@ AC_CHECK_PROGS([curl], [curl])
 CTNG_SET_KCONFIG_OPTION([curl])
 AC_SUBST([curl])
 
+AC_CHECK_PROGS([meson], [meson])
+CTNG_SET_KCONFIG_OPTION([meson])
+AC_SUBST([meson])
+
+AC_CHECK_PROGS([ninja], [ninja])
+CTNG_SET_KCONFIG_OPTION([ninja])
+AC_SUBST([ninja])
+
 CTNG_CPU_COUNT
 
 CTNG_PATH_TOOL_REQ([PATCH], [gpatch patch], [patch])

packages/picolibc/1.4.6/0000-libc-Create-a-macro-for-errno-so-that-GCC-tsystem.h-.patch

@@ -0,0 +1,33 @@
+From 1ce74e28ba8d6f91aca5830bfbc15897b68fcfac Mon Sep 17 00:00:00 2001
+From: Keith Packard <keithp@keithp.com>
+Date: Sun, 16 Aug 2020 12:44:31 -0700
+Subject: [PATCH] libc: Create a macro for 'errno' so that GCC tsystem.h works
+
+GCC's tsystem.h adds a declaration for errno if it isn't a CPP symbol,
+which it isn't in picolibc as it's just a regular global (thread
+local) variable. Create a function macro with no arguments so that
+
+Signed-off-by: Keith Packard <keithp@keithp.com>
+---
+ newlib/libc/include/sys/errno.h | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/newlib/libc/include/sys/errno.h b/newlib/libc/include/sys/errno.h
+index 0da73f44e..64f179bc0 100644
+--- a/newlib/libc/include/sys/errno.h
++++ b/newlib/libc/include/sys/errno.h
+@@ -59,6 +59,11 @@ extern NEWLIB_THREAD_LOCAL_ERRNO int errno;
+ 
+ #define __errno_r(ptr)	(errno)
+ #define __errno() 	(&errno)
++/*
++ * This lets applications check for #ifdef errno without requiring
++ * that errno be a parameter-less macro
++ */
++#define errno()		(errno)
+ 
+ #define	EPERM 1		/* Not owner */
+ #define	ENOENT 2	/* No such file or directory */
+-- 
+2.28.0
+

packages/picolibc/1.4.6/chksum

@@ -0,0 +1,4 @@
+md5 1.4.6.tar.gz 9f5cff6d36b278d02e05f4c717855f8c
+sha1 1.4.6.tar.gz de2579dab6cf488b476195edcaaa2b3829d3183f
+sha256 1.4.6.tar.gz 00764d0c0a2e8685fd9c91685ee8c404ef935975eaa07a55b15243558d390a00
+sha512 1.4.6.tar.gz 9a46f63f74292affcce5548968528c98b1614a49fd801a8192c4a276b727ca4355d3d3643daeb1c82a15c8eef703e2983110d95f49111e9f108d1f1760647172

packages/picolibc/package.desc

@@ -0,0 +1,7 @@
+origin='keithp.com'
+repository='git https://github.com/keith-packard/picolibc.git'
+milestones='1.4.6'
+archive_filename='@{version}'
+relevantpattern='*.*|.*. *.*|.'
+archive_formats='.tar.gz'
+mirrors='https://github.com/keith-packard/picolibc/archive'

samples/arm-picolibc-eabi/crosstool.config

@@ -0,0 +1,12 @@
+CT_CONFIG_VERSION="3"
+CT_ARCH_ARM=y
+CT_MULTILIB=y
+CT_ARCH_FLOAT_SW=y
+CT_TARGET_VENDOR="picolibc"
+CT_CC_LANG_CXX=n
+CT_LIBC="picolibc"
+CT_LIBC_NEWLIB=n
+CT_LIBC_PICOLIBC=y
+CT_CC_GCC_CONFIG_TLS=y
+CT_TARGET_CFLAGS="-ftls-model=local-exec"
+CT_CC_GCC_MULTILIB_LIST="rmprofile"

samples/arm-picolibc-eabi/reported.by

@@ -0,0 +1,3 @@
+reporter_name="Keith Packard"
+reporter_url="http://keithp.com/"
+reporter_comment="Based on arm-unknown-eabi"

scripts/build/libc/picolibc.sh

@@ -0,0 +1,111 @@
+# This file adds functions to build the Picolibc library
+# Copyright © 2020 Keith Packard
+# Licensed under the GPL v2 or later. See COPYING in the root of this package
+#
+# Edited by Keith Packard <keithp@keithp.com>
+#
+
+picolibc_start_files()
+{
+    CT_DoStep INFO "Installing C library headers & start files"
+    CT_DoExecLog ALL cp -a "${CT_SRC_DIR}/picolibc/newlib/libc/include/." \
+    "${CT_HEADERS_DIR}"
+    CT_EndStep
+}
+
+picolibc_main()
+{
+    local -a picolibc_opts
+    local cflags_for_target
+
+    CT_DoStep INFO "Installing C library"
+
+    CT_mkdir_pushd "${CT_BUILD_DIR}/build-libc"
+
+    CT_DoLog EXTRA "Configuring C library"
+
+    # Multilib is the default, so if it is not enabled, disable it.
+    if [ "${CT_MULTILIB}" != "y" ]; then
+        picolibc_opts+=("-Dmultilib=false")
+    fi
+
+    yn_args="IO_C99FMT:io-c99-formats
+IO_LL:io-long-long
+REGISTER_FINI:newlib-register-fini
+NANO_MALLOC:newlib-nano-malloc
+ATEXIT_DYNAMIC_ALLOC:newlib-atexit-dynamic-alloc
+GLOBAL_ATEXIT:newlib-global-atexit
+LITE_EXIT:lite-exit
+MULTITHREAD:newlib-multithread
+RETARGETABLE_LOCKING:newlib-retargetable-locking
+    "
+
+    for ynarg in $yn_args; do
+        var="CT_LIBC_PICOLIBC_${ynarg%:*}"
+        eval var=\$${var}
+        argument=${ynarg#*:}
+
+
+        if [ "${var}" = "y" ]; then
+            picolibc_opts+=( "-D$argument=true" )
+        else
+            picolibc_opts+=( "-D$argument=false" )
+        fi
+    done
+
+    [ "${CT_USE_SYSROOT}" = "y" ] && \
+	picolibc_opts+=( "-Dsysroot-install=true" )
+
+    [ "${CT_LIBC_PICOLIBC_EXTRA_SECTIONS}" = "y" ] && \
+        CT_LIBC_PICOLIBC_TARGET_CFLAGS="${CT_LIBC_PICOLIBC_TARGET_CFLAGS} -ffunction-sections -fdata-sections"
+
+    [ "${CT_LIBC_PICOLIBC_LTO}" = "y" ] && \
+        CT_LIBC_PICOLIBC_TARGET_CFLAGS="${CT_LIBC_PICOLIBC_TARGET_CFLAGS} -flto"
+
+    cflags_for_target="${CT_ALL_TARGET_CFLAGS} ${CT_LIBC_PICOLIBC_TARGET_CFLAGS}"
+
+    # Note: picolibc handles the build/host/target a little bit differently
+    # than one would expect:
+    #   build  : not used
+    #   host   : the machine building picolibc
+    #   target : the machine picolibc runs on
+	meson_cflags=""
+	for cflag in ${cflags_for_target}; do
+		meson_cflags="${meson_cflags} '${cflag}',"
+	done
+	cat << EOF > picolibc-cross.txt
+[binaries]
+c = '${CT_TARGET}-gcc'
+ar = '${CT_TARGET}-ar'
+as = '${CT_TARGET}-as'
+strip = '${CT_TARGET}-strip'
+
+[host_machine]
+system = 'none'
+cpu_family = 'arm'
+cpu = 'arm'
+endian = 'little'
+
+[properties]
+c_args = [ ${meson_cflags} '-nostdlib', '-fno-common', '-ftls-model=local-exec' ]
+needs_exe_wrapper = true
+skip_sanity_check = true
+EOF
+    CT_DoExecLog CFG                                               \
+    meson                                                          \
+        --cross-file picolibc-cross.txt                            \
+        --prefix=${CT_SYSROOT_DIR}                                 \
+	-Dspecsdir=${CT_SYSROOT_DIR}/lib                           \
+        "${CT_SRC_DIR}/picolibc"                                   \
+        "${picolibc_opts[@]}"                                      \
+        "${CT_LIBC_PICOLIBC_EXTRA_CONFIG_ARRAY[@]}"
+
+    CT_DoLog EXTRA "Building C library"
+    CT_DoExecLog ALL ninja
+
+    CT_DoLog EXTRA "Installing C library"
+    CT_DoExecLog ALL ninja install
+
+    CT_Popd
+    CT_EndStep
+}