Merge pull request #14827 from keith-packard/pr/libc/picolibc

Pr/libc/picolibc

Makefile.dep

@@ -479,6 +479,14 @@ ifneq (,$(filter posix_select,$(USEMODULE)))
   USEMODULE += xtimer
 endif
 
+ifneq (,$(filter picolibc,$(USEMODULE)))
+  # allow custom picolibc syscalls implementations by adding
+  # picolibc_syscalls_XXX to USEMODULE
+  ifeq (,$(filter picolibc_syscalls_%,$(USEMODULE)))
+    USEMODULE += picolibc_syscalls_default
+  endif
+endif
+
 ifneq (,$(filter posix_sockets,$(USEMODULE)))
   USEMODULE += bitfield
   USEMODULE += random

core/include/thread.h

@@ -176,6 +176,10 @@ struct _thread {
     const char *name;               /**< thread's name                  */
     int stack_size;                 /**< thread's stack size            */
 #endif
+/* enable TLS only when Picolibc is compiled with TLS enabled */
+#ifdef PICOLIBC_TLS
+    void *tls;                      /**< thread local storage ptr */
+#endif
 #ifdef HAVE_THREAD_ARCH_T
     thread_arch_t arch;             /**< architecture dependent part    */
 #endif

core/sched.c

@@ -40,6 +40,10 @@
 #include <inttypes.h>
 #endif
 
+#ifdef PICOLIBC_TLS
+#include <picotls.h>
+#endif
+
 /* Needed by OpenOCD to read sched_threads */
 #if defined(__APPLE__) && defined(__MACH__)
  #define FORCE_USED_SECTION __attribute__((used)) __attribute__((section( \
@@ -148,6 +152,9 @@ int __attribute__((used)) sched_run(void)
     next_thread->status = STATUS_RUNNING;
     sched_active_pid = next_thread->pid;
     sched_active_thread = next_thread;
+#ifdef PICOLIBC_TLS
+    _set_tls(next_thread->tls);
+#endif
 
 #ifdef MODULE_MPU_STACK_GUARD
     mpu_configure(

core/thread.c

@@ -20,6 +20,9 @@
 
 #include <errno.h>
 #include <stdio.h>
+#ifdef PICOLIBC_TLS
+#include <picotls.h>
+#endif
 
 #include "assert.h"
 #include "thread.h"
@@ -215,6 +218,13 @@ kernel_pid_t thread_create(char *stack, int stacksize, uint8_t priority,
     /* allocate our thread control block at the top of our stackspace */
     thread_t *thread = (thread_t *)(stack + stacksize);
 
+#ifdef PICOLIBC_TLS
+    stacksize -= _tls_size();
+
+    thread->tls = stack + stacksize;
+    _init_tls(thread->tls);
+#endif
+
 #if defined(DEVELHELP) || defined(SCHED_TEST_STACK)
     if (flags & THREAD_CREATE_STACKTEST) {
         /* assign each int of the stack the value of it's address */

cpu/arm7_common/arm7_init.c

@@ -127,7 +127,7 @@ void bootloader(void)
     /* cpu specific setup of clocks, peripherals */
     cpu_init();
 
-#ifdef MODULE_NEWLIB
+#if defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)
     extern void __libc_init_array(void);
     __libc_init_array();
 #endif

cpu/cortexm_common/Makefile.dep

@@ -4,11 +4,15 @@ USEMODULE += cortexm_common
 # include common periph code
 USEMODULE += cortexm_common_periph
 
-# all cortex MCU's use newlib as libc
-USEMODULE += newlib
-
-# use the nano-specs of Newlib when available
-USEMODULE += newlib_nano
+ifeq (1,$(PICOLIBC))
+  # Use Picolibc when explicitly selected
+  USEMODULE += picolibc
+else
+  # all cortex MCU's use newlib as libc
+  USEMODULE += newlib
+  # use the nano-specs of Newlib when available
+  USEMODULE += newlib_nano
+endif
 
 # Export the peripheral drivers to be linked into the final binary:
 USEMODULE += periph

cpu/cortexm_common/ldscripts/cortexm_base.ld

@@ -96,6 +96,42 @@ SECTIONS
         _efixed = .;            /* End of text section */
     } > rom
 
+    /*
+     * TLS relocations are offsets relative to the address
+     * of the first TLS symbol. That means we just need to
+     * allocate them all together so that the TLS region
+     * is compact when allocated for each thread.
+     */
+
+    /*
+     * TLS initialization data is loaded into ROM so that
+     * each thread can get its values initialized from there
+     * at startup
+     */
+    .tdata :
+    {
+         __tdata_start = .;
+        *(.tdata .tdata.* .gnu.linkonce.td.*)
+        __tdata_end = .;
+    } > rom
+    __tdata_source = LOADADDR(.tdata);
+    __tdata_size = SIZEOF(.tdata);
+
+    /*
+     * TLS zeroed data is relocated as if it immediately followed
+     * the tdata values. However, the linker 'magically' erases the
+     * memory allocation so that no ROM is consumed by this
+     * section
+     */
+    .tbss :
+    {
+        *(.tbss .tbss.* .gnu.linkonce.tb.*)
+        *(.tcommon)
+        __tbss_end = .;
+    } > rom
+    __tls_size = __tbss_end - __tdata_start;
+    __tbss_size = __tls_size - __tdata_size;
+
     /* .ARM.exidx is sorted, so has to go in its own output section.  */
     PROVIDE_HIDDEN (__exidx_start = .);
     .ARM.exidx :

cpu/cortexm_common/vectors_cortexm.c

@@ -174,7 +174,7 @@ void reset_handler_default(void)
     /* initialize the board (which also initiates CPU initialization) */
     board_init();
 
-#if MODULE_NEWLIB
+#if MODULE_NEWLIB || MODULE_PICOLIBC
     /* initialize std-c library (this must be done after board_init) */
     extern void __libc_init_array(void);
     __libc_init_array();

cpu/fe310/Makefile

@@ -2,6 +2,10 @@
 MODULE = cpu
 
 # add a list of subdirectories, that should also be built
-DIRS = periph nano vendor
+DIRS = periph vendor
+
+ifneq (1,$(PICOLIBC))
+  DIRS += nano
+endif
 
 include $(RIOTBASE)/Makefile.base

cpu/fe310/Makefile.dep

@@ -1,6 +1,10 @@
-USEMODULE += newlib_nano
+ifeq (1,$(PICOLIBC))
+  USEMODULE += picolibc
+else
+  USEMODULE += newlib_nano
+  USEMODULE += newlib_syscalls_fe310
+endif
 
-USEMODULE += newlib_syscalls_fe310
 USEMODULE += sifive_drivers_fe310
 
 USEMODULE += periph

cpu/fe310/cpu.c

@@ -24,6 +24,8 @@
 #include "vendor/encoding.h"
 #include "vendor/plic_driver.h"
 
+#include "stdio_uart.h"
+
 /*
  * Configure the memory mapped flash for faster throughput
  * to minimize interrupt latency on an I-Cache miss and refill
@@ -110,8 +112,12 @@ void cpu_init(void)
     /* Initialize IRQs */
     irq_init();
 
+    /* Initialize stdio */
+    stdio_init();
+#ifndef _PICOLIBC__
     /* Initialize newlib-nano library stubs */
     nanostubs_init();
+#endif /* PICOLIBC */
 
     /* Initialize static peripheral */
     periph_init();

cpu/fe310/ldscripts/fe310_base.ld

@@ -27,6 +27,7 @@ PHDRS
   flash PT_LOAD;
   ram_init PT_LOAD;
   ram PT_NULL;
+  tls PT_TLS;
 }
 
 SECTIONS
@@ -118,6 +119,42 @@ SECTIONS
     KEEP (*(.dtors))
   } >flash AT>flash :flash
 
+  /*
+   * TLS relocations are offsets relative to the address
+   * of the first TLS symbol. That means we just need to
+   * allocate them all together so that the TLS region
+   * is compact when allocated for each thread.
+   */
+
+  /*
+   * TLS initialization data is loaded into ROM so that
+   * each thread can get its values initialized from there
+   * at startup
+   */
+  .tdata :
+  {
+       __tdata_start = .;
+      *(.tdata .tdata.* .gnu.linkonce.td.*)
+      __tdata_end = .;
+  } >flash AT>flash :tls
+  __tdata_source = LOADADDR(.tdata);
+  __tdata_size = SIZEOF(.tdata);
+
+  /*
+   * TLS zeroed data is relocated as if it immediately followed
+   * the tdata values. However, the linker 'magically' erases the
+   * memory allocation so that no ROM is consumed by this
+   * section
+   */
+  .tbss :
+  {
+      *(.tbss .tbss.* .gnu.linkonce.tb.*)
+      *(.tcommon)
+      __tbss_end = .;
+  } >flash : tls
+  __tls_size = __tbss_end - __tdata_start;
+  __tbss_size = __tls_size - __tdata_size;
+
   .lalign         :
   {
     . = ALIGN(4);

cpu/fe310/nano/nanostubs.c

@@ -40,7 +40,6 @@ void nanostubs_init(void)
 {
 #if defined(MODULE_STDIO_UART)
     /* STDIO redirected to UART, no line buffering */
-    stdio_init();
     setvbuf(stdout, NULL, _IONBF, 0);
 #endif
 }

cpu/fe310/start.S

@@ -43,8 +43,6 @@ _start:
 2:
 
     /* Call global constructors */
-    la a0, __libc_fini_array
-    call atexit
     call __libc_init_array
 
 

examples/filesystem/main.c

@@ -240,9 +240,9 @@ static int _cat(int argc, char **argv)
         printf("Usage: %s <file>\n", argv[0]);
         return 1;
     }
-    /* With newlib, low-level syscalls are plugged to RIOT vfs
+    /* With newlib or picolibc, low-level syscalls are plugged to RIOT vfs
      * on native, open/read/write/close/... are plugged to RIOT vfs */
-#ifdef MODULE_NEWLIB
+#if defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)
     FILE *f = fopen(argv[1], "r");
     if (f == NULL) {
         printf("file %s does not exist\n", argv[1]);
@@ -276,7 +276,7 @@ static int _tee(int argc, char **argv)
         return 1;
     }
 
-#ifdef MODULE_NEWLIB
+#if defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)
     FILE *f = fopen(argv[1], "w+");
     if (f == NULL) {
         printf("error while trying to create %s\n", argv[1]);

makefiles/docker.inc.mk

@@ -57,6 +57,7 @@ export DOCKER_ENV_VARS += \
   PREFIX \
   QUIET \
   WERROR \
+  PICOLIBC \
   PROGRAMMER \
   RIOT_CI_BUILD \
   RIOT_VERSION \

makefiles/libc/picolibc.mk

@@ -0,0 +1,25 @@
+ifneq (,$(filter picolibc,$(USEMODULE)))
+  # Test if picolibc.specs is available
+  ifeq ($(shell $(LINK) -specs=picolibc.specs -E - 2>/dev/null >/dev/null </dev/null ; echo $$?),0)
+    USE_PICOLIBC = 1
+    ifeq ($(shell echo "int main(){} void _exit(int n) {(void)n;while(1);}" | LC_ALL=C $(CC) -xc - -o /dev/null -lc -specs=picolibc.specs -Wall -Wextra -pedantic 2>&1 | grep -q "use of wchar_t values across objects may fail" ; echo $$?),0)
+        CFLAGS += -fshort-wchar
+        LINKFLAGS += -Wl,--no-wchar-size-warning
+    endif
+  endif
+endif
+
+ifeq (1,$(USE_PICOLIBC))
+  LINKFLAGS += -specs=picolibc.specs
+  # RIOT uses _sheap and _eheap for heap start and end, PicoLIBC uses
+  # __heap_start and __heap_end. This glues these different names together.
+  LINKFLAGS += -Wl,--defsym=__heap_end=_eheap
+  LINKFLAGS += -Wl,--defsym=__heap_start=_sheap
+  CFLAGS += -specs=picolibc.specs
+  ifeq (,$(filter printf_float scanf_float,$(USEMODULE)))
+   CFLAGS += -DPICOLIBC_INTEGER_PRINTF_SCANF
+   LINKFLAGS += -DPICOLIBC_INTEGER_PRINTF_SCANF
+  endif
+endif
+
+LINKFLAGS += -lc

makefiles/pseudomodules.inc.mk

@@ -85,6 +85,7 @@ PSEUDOMODULES += newlib
 PSEUDOMODULES += newlib_gnu_source
 PSEUDOMODULES += newlib_nano
 PSEUDOMODULES += openthread
+PSEUDOMODULES += picolibc
 PSEUDOMODULES += pktqueue
 PSEUDOMODULES += posix_headers
 PSEUDOMODULES += printf_float

makefiles/stdio.inc.mk

@@ -8,7 +8,7 @@ STDIO_MODULES = \
   stdio_uart \
   #
 
-ifneq (,$(filter newlib,$(USEMODULE)))
+ifneq (,$(filter newlib picolibc,$(USEMODULE)))
   ifeq (,$(filter $(STDIO_MODULES),$(USEMODULE)))
     USEMODULE += stdio_uart
   endif

sys/Makefile.include

@@ -68,10 +68,18 @@ ifneq (,$(filter newlib,$(USEMODULE)))
   include $(RIOTMAKE)/libc/newlib.mk
 endif
 
+ifneq (,$(filter picolibc,$(USEMODULE)))
+  include $(RIOTMAKE)/libc/picolibc.mk
+endif
+
 ifneq (,$(filter newlib_syscalls_default,$(USEMODULE)))
   include $(RIOTBASE)/sys/newlib_syscalls_default/Makefile.include
 endif
 
+ifneq (,$(filter picolibc_syscalls_default,$(USEMODULE)))
+  include $(RIOTBASE)/sys/picolibc_syscalls_default/Makefile.include
+endif
+
 ifneq (,$(filter arduino,$(USEMODULE)))
   include $(RIOTBASE)/sys/arduino/Makefile.include
 endif

sys/log/log_color/log_module.h

@@ -110,7 +110,7 @@ static inline void log_write(unsigned level, const char *format, ...)
     va_end(args);
     printf(LOG_RESET_ANSI_COLOR_CODE);
 
-#ifdef MODULE_NEWLIB
+#if defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)
     /* no fflush on msp430 */
     fflush(stdout);
 #endif

sys/picolibc_syscalls_default/Makefile

@@ -0,0 +1 @@
+include $(RIOTBASE)/Makefile.base

sys/picolibc_syscalls_default/Makefile.include

@@ -0,0 +1 @@
+UNDEF += $(BINDIR)/picolibc_syscalls_default/syscalls.o

sys/picolibc_syscalls_default/syscalls.c

@@ -0,0 +1,357 @@
+/*
+ * Copyright (C) 2019 Koen Zandberg
+ *
+ * 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.
+ */
+
+/**
+ * @defgroup    sys_picolibc PicoLibc system call
+ * @ingroup     sys
+ * @brief       PicoLibc system call
+ * @{
+ *
+ * @file
+ * @brief       PicoLibc system call implementations
+ *
+ * @author      Koen Zandberg <koen@bergzand.net>
+ *
+ * @}
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <sys/times.h>
+
+#include "log.h"
+#include "periph/pm.h"
+#include "stdio_base.h"
+
+/**
+ * @brief Exit a program without cleaning up files
+ *
+ * If your system doesn't provide this, it is best to avoid linking with subroutines that
+ * require it (exit, system).
+ *
+ * @param n     the exit code, 0 for all OK, >0 for not OK
+ */
+void __attribute__((__noreturn__))
+_exit(int n)
+{
+    LOG_INFO("#! exit %i: powering off\n", n);
+    pm_off();
+    while(1);
+}
+
+/**
+ * @brief Send a signal to a thread
+ *
+ * @param[in] pid the pid to send to
+ * @param[in] sig the signal to send
+ *
+ * @return    always returns -1 to signal error
+ */
+__attribute__ ((weak))
+int kill(pid_t pid, int sig)
+{
+    (void) pid;
+    (void) sig;
+    errno = ESRCH;                         /* not implemented yet */
+    return -1;
+}
+
+#include "mutex.h"
+
+static mutex_t picolibc_put_mutex = MUTEX_INIT;
+
+#define PICOLIBC_STDOUT_BUFSIZE 64
+
+static char picolibc_stdout[PICOLIBC_STDOUT_BUFSIZE];
+static int picolibc_stdout_queued;
+
+static void _picolibc_flush(void)
+{
+    if (picolibc_stdout_queued) {
+        stdio_write(picolibc_stdout, picolibc_stdout_queued);
+        picolibc_stdout_queued = 0;
+    }
+}
+
+static int picolibc_put(char c, FILE *file)
+{
+    (void)file;
+    mutex_lock(&picolibc_put_mutex);
+    picolibc_stdout[picolibc_stdout_queued++] = c;
+    if (picolibc_stdout_queued == PICOLIBC_STDOUT_BUFSIZE || c == '\n')
+        _picolibc_flush();
+    mutex_unlock(&picolibc_put_mutex);
+    return 1;
+}
+
+static int picolibc_flush(FILE *file)
+{
+    (void)file;
+    mutex_lock(&picolibc_put_mutex);
+    _picolibc_flush();
+    mutex_unlock(&picolibc_put_mutex);
+    return 0;
+}
+
+static int picolibc_get(FILE *file)
+{
+    (void)file;
+    picolibc_flush(NULL);
+    char c = 0;
+    stdio_read(&c, 1);
+    return c;
+}
+
+FILE picolibc_stdio =
+    FDEV_SETUP_STREAM(picolibc_put, picolibc_get, picolibc_flush, _FDEV_SETUP_RW);
+
+FILE *const __iob[] = {
+    &picolibc_stdio,    /* stdin  */
+    &picolibc_stdio,    /* stdout */
+    &picolibc_stdio,    /* stderr */
+};
+
+#include <thread.h>
+/**
+ * @brief Get the process-ID of the current thread
+ *
+ * @return      the process ID of the current thread
+ */
+pid_t getpid(void)
+{
+    return thread_getpid();
+}
+
+#if MODULE_VFS
+#include "vfs.h"
+
+/**
+ * @brief Open a file
+ *
+ * This is a wrapper around @c vfs_open
+ *
+ * @param name  file name to open
+ * @param flags flags, see man 3p open
+ * @param mode  mode, file creation mode if the file is created when opening
+ *
+ * @return      fd number (>= 0) on success
+ * @return      -1 on error, @c errno set to a constant from errno.h to indicate the error
+ */
+int open(const char *name, int flags, int mode)
+{
+    int fd = vfs_open(name, flags, mode);
+    if (fd < 0) {
+        /* vfs returns negative error codes */
+        errno = -fd;
+        return -1;
+    }
+    return fd;
+}
+
+/**
+ * @brief Read bytes from an open file
+ *
+ * This is a wrapper around @c vfs_read
+ *
+ * @param[in]  fd     open file descriptor obtained from @c open()
+ * @param[out] dest   destination buffer
+ * @param[in]  count  maximum number of bytes to read
+ *
+ * @return       number of bytes read on success
+ * @return       -1 on error, @c errno set to a constant from errno.h to indicate the error
+ */
+_READ_WRITE_RETURN_TYPE read(int fd, void *dest, size_t count)
+{
+    int res = vfs_read(fd, dest, count);
+    if (res < 0) {
+        /* vfs returns negative error codes */
+        errno = -res;
+        return -1;
+    }
+    return res;
+}
+
+/**
+ * @brief Write bytes to an open file
+ *
+ * This is a wrapper around @c vfs_write
+ *
+ * @param[in]  fd     open file descriptor obtained from @c open()
+ * @param[in]  src    source data buffer
+ * @param[in]  count  maximum number of bytes to write
+ *
+ * @return       number of bytes written on success
+ * @return       -1 on error, @c errno set to a constant from errno.h to indicate the error
+ */
+_READ_WRITE_RETURN_TYPE write(int fd, const void *src, size_t count)
+{
+    int res = vfs_write(fd, src, count);
+    if (res < 0) {
+        /* vfs returns negative error codes */
+        errno = -res;
+        return -1;
+    }
+    return res;
+}
+
+/**
+ * @brief Close an open file
+ *
+ * This is a wrapper around @c vfs_close
+ *
+ * If this call returns an error, the fd should still be considered invalid and
+ * no further attempt to use it shall be made, not even to retry @c close()
+ *
+ * @param[in]  fd     open file descriptor obtained from @c open()
+ *
+ * @return       0 on success
+ * @return       -1 on error, @c errno set to a constant from errno.h to indicate the error
+ */
+int close(int fd)
+{
+    int res = vfs_close(fd);
+    if (res < 0) {
+        /* vfs returns negative error codes */
+        errno = -res;
+        return -1;
+    }
+    return res;
+}
+
+/**
+ * Current process times (not implemented).
+ *
+ * @param[out]  ptms    Not modified.
+ *
+ * @return  -1, this function always fails. errno is set to ENOSYS.
+ */
+clock_t times(struct tms *ptms)
+{
+    (void)ptms;
+    errno = ENOSYS;
+
+    return (-1);
+}
+
+/**
+ * @brief Query or set options on an open file
+ *
+ * This is a wrapper around @c vfs_fcntl
+ *
+ * @param[in]  fd     open file descriptor obtained from @c open()
+ * @param[in]  cmd    fcntl command, see man 3p fcntl
+ * @param[in]  arg    argument to fcntl command, see man 3p fcntl
+ *
+ * @return       0 on success
+ * @return       -1 on error, @c errno set to a constant from errno.h to indicate the error
+ */
+int fcntl (int fd, int cmd, int arg)
+{
+    int res = vfs_fcntl(fd, cmd, arg);
+    if (res < 0) {
+        /* vfs returns negative error codes */
+        errno = -res;
+        return -1;
+    }
+    return res;
+}
+
+/**
+ * @brief Seek to position in file
+ *
+ * This is a wrapper around @c vfs_lseek
+ *
+ * @p whence determines the function of the seek and should be set to one of
+ * the following values:
+ *
+ *  - @c SEEK_SET: Seek to absolute offset @p off
+ *  - @c SEEK_CUR: Seek to current location + @p off
+ *  - @c SEEK_END: Seek to end of file + @p off
+ *
+ * @param[in]  fd       open file descriptor obtained from @c open()
+ * @param[in]  off      seek offset
+ * @param[in]  whence   determines the seek method, see detailed description
+ *
+ * @return the new seek location in the file on success
+ * @return -1 on error, @c errno set to a constant from errno.h to indicate the error
+ */
+off_t lseek(int fd, _off_t off, int whence)
+{
+    int res = vfs_lseek(fd, off, whence);
+    if (res < 0) {
+        /* vfs returns negative error codes */
+        errno = -res;
+        return -1;
+    }
+    return res;
+}
+
+/**
+ * @brief Get status of an open file
+ *
+ * This is a wrapper around @c vfs_fstat
+ *
+ * @param[in]  fd       open file descriptor obtained from @c open()
+ * @param[out] buf      pointer to stat struct to fill
+ *
+ * @return 0 on success
+ * @return -1 on error, @c errno set to a constant from errno.h to indicate the error
+ */
+int fstat(int fd, struct stat *buf)
+{
+    int res = vfs_fstat(fd, buf);
+    if (res < 0) {
+        /* vfs returns negative error codes */
+        errno = -res;
+        return -1;
+    }
+    return 0;
+}
+
+/**
+ * @brief Status of a file (by name)
+ *
+ * This is a wrapper around @c vfs_fstat
+ *
+ * @param[in]  name     path to file
+ * @param[out] buf      pointer to stat struct to fill
+ *
+ * @return 0 on success
+ * @return -1 on error, @c errno set to a constant from errno.h to indicate the error
+ */
+int stat(const char *name, struct stat *st)
+{
+    int res = vfs_stat(name, st);
+    if (res < 0) {
+        /* vfs returns negative error codes */
+        errno = -res;
+        return -1;
+    }
+    return 0;
+}
+
+/**
+ * @brief  Unlink (delete) a file
+ *
+ * @param[in]  path     path to file to be deleted
+ *
+ * @return 0 on success
+ * @return -1 on error, @c errno set to a constant from errno.h to indicate the error
+ */
+int unlink(const char *path)
+{
+    int res = vfs_unlink(path);
+    if (res < 0) {
+        /* vfs returns negative error codes */
+        errno = -res;
+        return -1;
+    }
+    return 0;
+}
+
+#endif /* MODULE_VFS */

sys/posix/include/fcntl.h

@@ -16,7 +16,7 @@
  */
 
 #ifndef DOXYGEN
-#if defined(CPU_NATIVE) || MODULE_NEWLIB
+#if defined(CPU_NATIVE) || MODULE_NEWLIB || MODULE_PICOLIBC
 /* If building on native or newlib we need to use the system header instead */
 #pragma GCC system_header
 /* without the GCC pragma above #include_next will trigger a pedantic error */

sys/posix/include/sys/select.h

@@ -30,8 +30,9 @@
 #define SYS_SELECT_H
 
 #include <string.h>
-/* prevent cyclic dependency with newlib's `sys/types.h` */
-#if defined(MODULE_NEWLIB) && !defined(CPU_ESP32) && !defined(CPU_ESP8266)
+/* prevent cyclic dependency with newlib/picolibc's `sys/types.h` */
+#if (defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)) && \
+    !defined(CPU_ESP32) && !defined(CPU_ESP8266)
 #include <sys/_timeval.h>
 #else
 #include <sys/time.h>

sys/progress_bar/progress_bar.c

@@ -72,7 +72,7 @@ void progress_bar_print(char *prefix, char *suffix, uint8_t value)
     /* show cursor */
     printf("\033[?25h");
 
-#ifdef MODULE_NEWLIB
+#if defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)
     fflush(stdout);
 #endif
 }

sys/shell/commands/sc_sntp.c

@@ -82,7 +82,7 @@ int _ntpdate(int argc, char **argv)
         puts("Error in synchronization");
         return 1;
     }
-#ifdef MODULE_NEWLIB
+#if defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)
     struct tm *tm;
     time_t time = (time_t)(sntp_get_unix_usec() / US_PER_SEC);
 

sys/shell/shell.c

@@ -42,11 +42,11 @@
 #define BS  '\x08'  /** ASCII "Backspace" */
 #define DEL '\x7f'  /** ASCII "Delete" */
 
-#ifdef MODULE_NEWLIB
+#if defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)
     #define flush_if_needed() fflush(stdout)
 #else
     #define flush_if_needed()
-#endif /* MODULE_NEWLIB */
+#endif /* MODULE_NEWLIB || MODULE_PICOLIBC */
 
 #ifndef SHELL_NO_ECHO
     #define ECHO_ON 1

tests/bloom_bytes/main.c

@@ -110,7 +110,7 @@ int main(void)
     double false_positive_rate = (double) in / (double) lenA;
     /* Use 'fmt/print_float' to work on all platforms (atmega)
      * Stdout should be flushed before to prevent garbled output. */
-#ifdef MODULE_NEWLIB
+#if defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)
     fflush(stdout);
 #endif
     print_float(false_positive_rate, 6);

tests/pkg_fatfs_vfs/main.c

@@ -325,16 +325,16 @@ static void test_fstat(void)
     print_test_result("test_stat__umount", vfs_umount(&_test_vfs_mount) == 0);
 }
 
-#ifdef MODULE_NEWLIB
-static void test_newlib(void)
+#if defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)
+static void test_libc(void)
 {
     FILE* fl;
     char buf[sizeof(test_txt) + sizeof(test_txt2)];
-    print_test_result("test_newlib__mount", vfs_mount(&_test_vfs_mount) == 0);
+    print_test_result("test_libc__mount", vfs_mount(&_test_vfs_mount) == 0);
 
     /* try to open file that doesn't exist */
     fl = fopen(FULL_FNAME_NXIST, "r");
-    print_test_result("test_newlib__fopen", fl == NULL);
+    print_test_result("test_libc__fopen", fl == NULL);
     if (fl) {
         fclose(fl);
     }
@@ -342,52 +342,52 @@ static void test_newlib(void)
     /* create new file write and check content */
     remove(FULL_FNAME2);
     fl = fopen(FULL_FNAME2, "w+");
-    print_test_result("test_newlib__fopen_w", fl != NULL);
+    print_test_result("test_libc__fopen_w", fl != NULL);
     if (fl) {
-        print_test_result("test_newlib__fputs_w", fputs(test_txt, fl) >= 0);
+        print_test_result("test_libc__fputs_w", fputs(test_txt, fl) >= 0);
         rewind(fl);
-        print_test_result("test_newlib__fread_w",
+        print_test_result("test_libc__fread_w",
                 fread(buf, sizeof(*buf), sizeof(buf), fl) > 0);
-        print_test_result("test_newlib__strcmp_w", strcmp(test_txt, buf) == 0);
-        print_test_result("test_newlib__fclose_w", fclose(fl) == 0);
+        print_test_result("test_libc__strcmp_w", strcmp(test_txt, buf) == 0);
+        print_test_result("test_libc__fclose_w", fclose(fl) == 0);
     }
 
     /* cppcheck-suppress resourceLeak
      * (reason: cppcheck <2.0 reports a false positive here) */
     fl = fopen(FULL_FNAME2, "r"); /* open file RO */
-    print_test_result("test_newlib__fopen_r", fl != NULL);
+    print_test_result("test_libc__fopen_r", fl != NULL);
     if (fl) {
-        print_test_result("test_newlib__fclose_r", fclose(fl) == 0);
+        print_test_result("test_libc__fclose_r", fclose(fl) == 0);
     }
 
     /* remove file */
-    print_test_result("test_newlib__remove", remove(FULL_FNAME2) == 0);
+    print_test_result("test_libc__remove", remove(FULL_FNAME2) == 0);
 
     /* append to non existing file */
     fl = fopen(FULL_FNAME2, "a");
-    print_test_result("test_newlib__fopen_a", fl != NULL);
+    print_test_result("test_libc__fopen_a", fl != NULL);
     if (fl) {
-        print_test_result("test_newlib__fputs_a", fputs(test_txt, fl) >= 0);
-        print_test_result("test_newlib__fclose_a", fclose(fl) == 0);
+        print_test_result("test_libc__fputs_a", fputs(test_txt, fl) >= 0);
+        print_test_result("test_libc__fclose_a", fclose(fl) == 0);
     }
 
     /* append to existing file and check content */
     fl = fopen(FULL_FNAME2, "a+");
-    print_test_result("test_newlib__fopen_a2", fl != NULL);
+    print_test_result("test_libc__fopen_a2", fl != NULL);
     if (fl) {
-        print_test_result("test_newlib__fputs_a2", fputs(test_txt2, fl) >= 0);
+        print_test_result("test_libc__fputs_a2", fputs(test_txt2, fl) >= 0);
         rewind(fl);
-        print_test_result("test_newlib__fread_a2",
+        print_test_result("test_libc__fread_a2",
                 fread(buf, sizeof(*buf), sizeof(buf), fl) > 0);
-        print_test_result("test_newlib__strcmp_a2",
+        print_test_result("test_libc__strcmp_a2",
                 strncmp(test_txt, buf, strlen(test_txt)) == 0);
-        print_test_result("test_newlib__strcmp_a2", strncmp(test_txt2,
+        print_test_result("test_libc__strcmp_a2", strncmp(test_txt2,
                     &buf[strlen(test_txt)], strlen(test_txt2)) == 0);
-        print_test_result("test_newlib__fclose_a2", fclose(fl) == 0);
+        print_test_result("test_libc__fclose_a2", fclose(fl) == 0);
     }
-    print_test_result("test_newlib__remove", remove(FULL_FNAME2) == 0);
+    print_test_result("test_libc__remove", remove(FULL_FNAME2) == 0);
 
-    print_test_result("test_newlib__umount", vfs_umount(&_test_vfs_mount) == 0);
+    print_test_result("test_libc__umount", vfs_umount(&_test_vfs_mount) == 0);
 }
 #endif
 
@@ -421,8 +421,8 @@ int main(void)
     test_mkrmdir();
     test_create();
     test_fstat();
-#ifdef MODULE_NEWLIB
-    test_newlib();
+#if defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)
+    test_libc();
 #endif
 
     printf("Test end.\n");

tests/rng/test.c

@@ -389,7 +389,7 @@ void test_entropy(uint32_t samples)
     /* Use 'fmt/print_float' to work on all platforms (atmega)
      * Stdout should be flushed before to prevent garbled output. */
     printf("Calculated ");
-#ifdef MODULE_NEWLIB
+#if defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)
     /* no fflush on msp430 */
     fflush(stdout);
 #endif

tests/unittests/tests-vfs/tests-vfs-mount-constfs.c

@@ -171,7 +171,7 @@ static void test_vfs_constfs_read_lseek(void)
     TEST_ASSERT_EQUAL_INT(0, res);
 }
 
-#if MODULE_NEWLIB || defined(BOARD_NATIVE)
+#if MODULE_NEWLIB || MODULE_PICOLIBC || defined(BOARD_NATIVE)
 static void test_vfs_constfs__posix(void)
 {
     int res;
@@ -210,7 +210,7 @@ Test *tests_vfs_mount_constfs_tests(void)
         new_TestFixture(test_vfs_umount__invalid_mount),
         new_TestFixture(test_vfs_constfs_open),
         new_TestFixture(test_vfs_constfs_read_lseek),
-#if MODULE_NEWLIB || defined(BOARD_NATIVE)
+#if MODULE_NEWLIB || MODULE_PICOLIBC || defined(BOARD_NATIVE)
         new_TestFixture(test_vfs_constfs__posix),
 #endif
     };