[libc][picolibc] add tls support

bsp/qemu-vexpress-a9/link.lds

@@ -85,6 +85,35 @@ SECTIONS
  }
  __data_end = .;
 
+ . = ALIGN(8);
+ .tdata :
+ {
+ __tdata_start = .;
+ *(.tdata .tdata.* .gnu.linkonce.td.*)
+ __tdata_end = .;
+ }
+ __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 = .;
+ }
+ __tls_size = __tbss_end - __tdata_start;
+ __tbss_size = __tls_size - __tdata_size;
+ PROVIDE( __tbss_offset = ADDR(.tbss) - ADDR(.tdata) );
+ PROVIDE( __tls_align = MAX(ALIGNOF(.tdata), ALIGNOF(.tbss)) );
+ PROVIDE( __arm32_tls_tcb_offset = MAX(8, __tls_align) );
+ PROVIDE( __arm64_tls_tcb_offset = MAX(16, __tls_align) );
+
  . = ALIGN(4);
  __bss_start = .;
  .bss :

bsp/qemu-vexpress-a9/rtconfig.py

@@ -49,7 +49,9 @@ def get_mac_address():
  STRIP = PREFIX + 'strip'
  CFPFLAGS = ' -msoft-float'
  AFPFLAGS = ' -mfloat-abi=softfp -mfpu=neon'
- DEVICE = ' -march=armv7-a -mtune=cortex-a7 -ftree-vectorize -ffast-math -funwind-tables -fno-strict-aliasing'
+ DEVICE = ''
+ #DEVICE += ' --specs=picolibc.specs --picolibc-prefix=' + EXEC_PATH + '/../'
+ DEVICE += ' -march=armv7-a -mtune=cortex-a7 -ftree-vectorize -ffast-math -funwind-tables -fno-strict-aliasing'
 
  CXXFLAGS= DEVICE + CFPFLAGS + ' -Wall -fdiagnostics-color=always'
  CFLAGS = DEVICE + CFPFLAGS + ' -Wall -Wno-cpp -std=gnu99 -D_POSIX_SOURCE -fdiagnostics-color=always'

examples/libc/SConscript

@@ -1,6 +1,9 @@
 from building import *
 
 src = Glob('*.c')
-group = DefineGroup('UTest', src, depend = ['RT_USING_NEWLIBC', 'RT_USING_PTHREADS'])
+if GetDepend(['RT_USING_PICOLIBC']):
+ group = DefineGroup('UTest', src, depend = ['RT_USING_PTHREADS'])
+else:
+ group = DefineGroup('UTest', src, depend = ['RT_USING_NEWLIBC', 'RT_USING_PTHREADS'])
 
 Return('group')

examples/libc/tls.c

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date Author Notes
+ * 2023-12-19 iDings first version
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <finsh.h>
+#include <rtthread.h>
+
+static __thread int i;
+
+static void child_routine(void *param)
+{
+ printf("child_thread: i:%d\n", i);
+ i = 300;
+ printf("child_thread: i:%d\n", i);
+}
+
+static int tls_test(void)
+{
+ rt_thread_t child;
+
+ char name[RT_NAME_MAX];
+ rt_thread_get_name(rt_thread_self(), name, sizeof(name));
+
+ printf("i:%d\n", i);
+ i = 200;
+ printf("main_thread: i:%d\n", i);
+
+ child = rt_thread_create("tls_thread", child_routine, NULL, 4096, 10, 20);
+ rt_thread_startup(child);
+
+ sleep(1);
+ printf("main_thread: i:%d\n", i);
+
+ return 0;
+}
+MSH_CMD_EXPORT(tls_test, thread local storage example);

include/rtdef.h

@@ -71,6 +71,13 @@
 #endif /* defined(RT_USING_SIGNALS) || defined(RT_USING_SMART) */
 #endif /* RT_USING_NANO */
 
+#ifdef RT_USING_PICOLIBC
+#include <picolibc.h>
+#ifdef PICOLIBC_TLS
+#include <picotls.h>
+#endif
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -998,6 +1005,10 @@ struct rt_thread
 #endif
 #endif
 
+#ifdef PICOLIBC_TLS
+ void *tls;
+#endif
+
  rt_atomic_t ref_count;
  struct rt_spinlock spinlock;
  rt_ubase_t user_data; /**< private user data beyond this thread */

src/scheduler_mp.c

@@ -546,6 +546,9 @@ void rt_schedule(void)
  _rt_schedule_remove_thread(to_thread, RT_FALSE);
  to_thread->stat = RT_THREAD_RUNNING | (to_thread->stat & ~RT_THREAD_STAT_MASK);
 
+#ifdef PICOLIBC_TLS
+ _set_tls(to_thread->tls);
+#endif
  /* switch to new thread */
  LOG_D("[%d]switch to priority#%d "
  "thread:%.*s(sp:0x%08x), "
@@ -700,6 +703,9 @@ void rt_scheduler_do_irq_switch(void *context)
  _rt_schedule_remove_thread(to_thread, RT_FALSE);
  to_thread->stat = RT_THREAD_RUNNING | (to_thread->stat & ~RT_THREAD_STAT_MASK);
 
+#ifdef PICOLIBC_TLS
+ _set_tls(to_thread->tls);
+#endif
 #ifdef RT_USING_OVERFLOW_CHECK
  _scheduler_stack_check(to_thread);
 #endif /* RT_USING_OVERFLOW_CHECK */

src/scheduler_up.c

@@ -295,6 +295,9 @@ void rt_schedule(void)
  rt_schedule_remove_thread(to_thread);
  to_thread->stat = RT_THREAD_RUNNING | (to_thread->stat & ~RT_THREAD_STAT_MASK);
 
+#ifdef PICOLIBC_TLS
+ _set_tls(to_thread->tls);
+#endif
  /* switch to new thread */
  LOG_D("[%d]switch to priority#%d "
  "thread:%.*s(sp:0x%08x), "

src/thread.c

@@ -184,6 +184,15 @@ static rt_err_t _thread_init(struct rt_thread *thread,
  thread->entry = (void *)entry;
  thread->parameter = parameter;
 
+#ifdef PICOLIBC_TLS
+#define TLS_ALIGN (_tls_align() > 8 ? _tls_align() : 8)
+ char *tls = (char *)stack_start + stack_size - _tls_size();
+ thread->tls = (void *)RT_ALIGN_DOWN((rt_ubase_t)tls, TLS_ALIGN);
+ stack_size = (char *)thread->tls - (char *)stack_start;
+
+ _init_tls(thread->tls);
+#endif
+
  /* stack init */
  thread->stack_addr = stack_start;
  thread->stack_size = stack_size;