[PING^2]: [PATCH] newlib: import TLS initialization and helpers from picolibc
Torbjorn SVENSSON
torbjorn.svensson@foss.st.com
Mon Sep 7 15:35:41 GMT 2026
Gentle ping ^2 :)
The binutils patch was approved and merged last week.
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=1cc9aa9de2af3cd54d5433c0e4a522b73719c3cb
Kind regards,
Torbjörn
On 2026-08-28 15:09, Torbjorn SVENSSON wrote:
> Gentle ping! :)
>
> Kind regards,
> Torbjörn
>
> On 2026-08-20 12:00, Torbjörn SVENSSON wrote:
>> Hi,
>>
>> With the decision from Arm to build a GCC toolchain without --disable-tls,
>> newlib needs to have support in the start code to initialize the TLS block
>> and implement __aeabi_read_tp to allow GCC to know what thread is current.
>>
>> The change in the build rules were done in:
>> https://gitlab.arm.com/tooling/gnu-devtools-for-arm/-/commit/f6a8633309c850d62817859986a165c94f11babf
>>
>> Below patch imports the implementation from picolibc and leaves the header
>> filenames as-is, thus, the main header file to include in an application
>> is picotls.h
>>
>> Note: This implementation primarily targets TLS mode local-exec. Other
>> modes might require additional functions to be added.
>> Also, I've only ported the parts that I've seen as required for
>> arm-none-eabi, other targets might benefit from TLS support, but I do not
>> have access to other hardware to validate the implementation on.
>>
>> For TLS to be properly supported on arm-none-eabi, the following fix is
>> also required in ld:
>> https://sourceware.org/pipermail/binutils/2026-August/150870.html
>>
>>
>> Ok for master?
>>
>> Kind regards,
>> Torbjörn
>>
>> --
>>
>> This patch introduces, optional, TLS (thread local storage) initialization to
>> the startup code. It also brings in the same interface that is exposed to the
>> application from picolibc so that an application can initialize additional
>> blocks as needed and switch to them when switching tasks.
>>
>> The picolibc sources are kept as-is except for:
>>
>> - _BEGIN_STD_C -> __BEGIN_DECLS
>> - _END_STD_C -> __END_DECLS
>> - #include <picolibc.h> -> #include <newlib.h>
>>
>> Origin of the code is picolibc-1.8.12.
>>
>> This new feature is activated by --enable-newlib-thread-local-storage.
>>
>> Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>
>> ---
>> libgloss/arm/crt0.S | 13 ++++
>> newlib/configure | 21 ++++++
>> newlib/configure.ac | 13 ++++
>> newlib/libc/include/picotls.h | 76 +++++++++++++++++++++
>> newlib/libc/machine/arm/Makefile.inc | 1 +
>> newlib/libc/machine/arm/arm_tls.h | 60 +++++++++++++++++
>> newlib/libc/machine/arm/read_tp.S | 98 ++++++++++++++++++++++++++++
>> newlib/libc/machine/arm/set_tls.c | 79 ++++++++++++++++++++++
>> newlib/libc/machine/arm/tls.c | 52 +++++++++++++++
>> newlib/libc/misc/Makefile.inc | 1 +
>> newlib/libc/misc/inittls.c | 77 ++++++++++++++++++++++
>> newlib/libc/sys/arm/crt0.S | 13 ++++
>> newlib/newlib.hin | 6 ++
>> 13 files changed, 510 insertions(+)
>> create mode 100644 newlib/libc/include/picotls.h
>> create mode 100644 newlib/libc/machine/arm/arm_tls.h
>> create mode 100644 newlib/libc/machine/arm/read_tp.S
>> create mode 100644 newlib/libc/machine/arm/set_tls.c
>> create mode 100644 newlib/libc/machine/arm/tls.c
>> create mode 100644 newlib/libc/misc/inittls.c
>>
>> diff --git a/libgloss/arm/crt0.S b/libgloss/arm/crt0.S
>> index b9e768007..81033a3b2 100644
>> --- a/libgloss/arm/crt0.S
>> +++ b/libgloss/arm/crt0.S
>> @@ -388,6 +388,15 @@ __change_mode:
>> #endif
>>
>> bl FUNCTION (memset)
>> +
>> +#ifdef __THREAD_LOCAL_STORAGE
>> + /* Initialize TLS in local-exec mode. */
>> + ldr a1, .LCtls_base /* First arg: TLS block. */
>> + bl FUNCTION (_init_tls)
>> + ldr a1, .LCtls_base /* First arg: TLS block. */
>> + bl FUNCTION (_set_tls)
>> +#endif
>> +
>> #if !defined (ARM_RDP_MONITOR) && !defined (ARM_RDI_MONITOR)
>> /* Changes by toralf: Taken from libgloss/m68k/crt0.S
>> initialize target specific stuff. Only execute these
>> @@ -607,6 +616,10 @@ change_back:
>> .word __bss_start__
>> .LC2:
>> .word __bss_end__
>> +#ifdef __THREAD_LOCAL_STORAGE
>> +.LCtls_base:
>> + .word __tls_base
>> +#endif
>> #ifdef __USES_INITFINI__
>> #ifdef _LITE_EXIT
>> .Latexit:
>> diff --git a/newlib/configure b/newlib/configure
>> index ab31510aa..0ff110a7c 100755
>> --- a/newlib/configure
>> +++ b/newlib/configure
>> @@ -988,6 +988,7 @@ enable_newlib_global_atexit
>> enable_newlib_reent_small
>> enable_newlib_reent_binary_compat
>> enable_newlib_reent_thread_local
>> +enable_newlib_thread_local_storage
>> enable_newlib_global_stdio_streams
>> enable_newlib_fvwrite_in_streamio
>> enable_newlib_fseek_optimization
>> @@ -1659,6 +1660,7 @@ Optional Features:
>> --enable-newlib-reent-small enable small reentrant struct support
>> --enable-newlib-reent-binary-compat enable backward binary compatibility for struct _reent
>> --enable-newlib-reent-thread-local enable thread-local storage objects as a replacment for struct _reent members
>> + --enable-newlib-thread-local-storage enable the TLS runtime API
>> --enable-newlib-global-stdio-streams enable global stdio streams
>> --disable-newlib-fvwrite-in-streamio disable iov in streamio
>> --disable-newlib-fseek-optimization disable fseek optimization
>> @@ -2437,6 +2439,17 @@ else
>> newlib_reent_thread_local=no
>> fi
>> +# Check whether --enable-newlib-thread-local-storage was given.
>> +if test "${enable_newlib_thread_local_storage+set}" = set; then :
>> + enableval=$enable_newlib_thread_local_storage; case "${enableval}" in
>> + yes) newlib_thread_local_storage=yes ;;
>> + no) newlib_thread_local_storage=no ;;
>> + *) as_fn_error $? "bad value ${enableval} for newlib-thread-local-storage option" "$LINENO" 5 ;;
>> + esac
>> +else
>> + newlib_thread_local_storage=no
>> +fi
>> +
>> # Check whether --enable-newlib-global-stdio-streams was given.
>> if test "${enable_newlib_global_stdio_streams+set}" = set; then :
>> enableval=$enable_newlib_global_stdio_streams; case "${enableval}" in
>> @@ -6603,6 +6616,14 @@ $as_echo "#define _WANT_REENT_THREAD_LOCAL 1" >>confdefs.h
>> fi
>> +if test "${newlib_thread_local_storage}" = "yes"; then
>> +
>> +$as_echo "#define __THREAD_LOCAL_STORAGE 1" >>confdefs.h
>> +
>> +$as_echo "#define __THREAD_LOCAL_STORAGE_API 1" >>confdefs.h
>> +
>> +fi
>> +
>> _mb_len_max=1
>> if test "${newlib_mb}" = "yes"; then
>> diff --git a/newlib/configure.ac b/newlib/configure.ac
>> index a4807830e..0ade683a8 100644
>> --- a/newlib/configure.ac
>> +++ b/newlib/configure.ac
>> @@ -187,6 +187,14 @@ AC_ARG_ENABLE(newlib-reent-thread-local,
>> esac
>> fi], [newlib_reent_thread_local=no])dnl
>> +AC_ARG_ENABLE(newlib-thread-local-storage,
>> +[ --enable-newlib-thread-local-storage enable the TLS runtime API],
>> +[case "${enableval}" in
>> + yes) newlib_thread_local_storage=yes ;;
>> + no) newlib_thread_local_storage=no ;;
>> + *) AC_MSG_ERROR(bad value ${enableval} for newlib-thread-local-storage option) ;;
>> + esac], [newlib_thread_local_storage=no])dnl
>> +
>> dnl Support --enable-newlib-global-stdio-streams
>> dnl This is no longer optional. It is enabled in all Newlib configurations.
>> AC_ARG_ENABLE(newlib-global-stdio-streams,
>> @@ -478,6 +486,11 @@ if test "${newlib_reent_thread_local}" = "yes"; then
>> AC_DEFINE(_WANT_REENT_THREAD_LOCAL, 1, [Define to enable thread-local storage objects as a replacment for struct _reent members.])
>> fi
>> +if test "${newlib_thread_local_storage}" = "yes"; then
>> + AC_DEFINE(__THREAD_LOCAL_STORAGE, 1, [Define to enable the TLS runtime API.])
>> + AC_DEFINE(__THREAD_LOCAL_STORAGE_API, 1, [Define to enable the TLS runtime API.])
>> +fi
>> +
>> _mb_len_max=1
>> if test "${newlib_mb}" = "yes"; then
>> AC_DEFINE(_MB_CAPABLE, 1, [Multibyte supported.])
>> diff --git a/newlib/libc/include/picotls.h b/newlib/libc/include/picotls.h
>> new file mode 100644
>> index 000000000..e87f0b58a
>> --- /dev/null
>> +++ b/newlib/libc/include/picotls.h
>> @@ -0,0 +1,76 @@
>> +/*
>> + * SPDX-License-Identifier: BSD-3-Clause
>> + *
>> + * Copyright © 2019 Keith Packard
>> + *
>> + * Redistribution and use in source and binary forms, with or without
>> + * modification, are permitted provided that the following conditions
>> + * are met:
>> + *
>> + * 1. Redistributions of source code must retain the above copyright
>> + * notice, this list of conditions and the following disclaimer.
>> + *
>> + * 2. Redistributions in binary form must reproduce the above
>> + * copyright notice, this list of conditions and the following
>> + * disclaimer in the documentation and/or other materials provided
>> + * with the distribution.
>> + *
>> + * 3. Neither the name of the copyright holder nor the names of its
>> + * contributors may be used to endorse or promote products derived
>> + * from this software without specific prior written permission.
>> + *
>> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
>> + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
>> + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
>> + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
>> + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
>> + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
>> + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
>> + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
>> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
>> + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
>> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
>> + * OF THE POSSIBILITY OF SUCH DAMAGE.
>> + */
>> +
>> +#ifndef _PICOTLS_H_
>> +#define _PICOTLS_H_
>> +
>> +#include <sys/cdefs.h>
>> +
>> +#ifdef __THREAD_LOCAL_STORAGE
>> +
>> +#include <sys/types.h>
>> +
>> +__BEGIN_DECLS
>> +
>> +extern char __tls_size[];
>> +
>> +static inline size_t
>> +_tls_size(void)
>> +{
>> + return (size_t)(uintptr_t)__tls_size;
>> +}
>> +
>> +extern char __tls_align[];
>> +
>> +static inline size_t
>> +_tls_align(void)
>> +{
>> + return (size_t)(uintptr_t)__tls_align;
>> +}
>> +
>> +/*
>> + * Initialize a TLS block, copying the data segment from flash and
>> + * zeroing the BSS segment.
>> + */
>> +void _init_tls(void *tls);
>> +
>> +/* Set the TLS pointer to the specific block */
>> +void _set_tls(void *tls);
>> +
>> +__END_DECLS
>> +
>> +#endif
>> +
>> +#endif /* _PICOTLS_H_ */
>> diff --git a/newlib/libc/machine/arm/Makefile.inc b/newlib/libc/machine/arm/Makefile.inc
>> index 2d6c08d71..253e54620 100644
>> --- a/newlib/libc/machine/arm/Makefile.inc
>> +++ b/newlib/libc/machine/arm/Makefile.inc
>> @@ -3,6 +3,7 @@ libc_a_SOURCES += \
>> %D%/aeabi_memcpy.c %D%/aeabi_memcpy-armv7a.S \
>> %D%/aeabi_memmove.c %D%/aeabi_memmove-soft.S \
>> %D%/aeabi_memset.c %D%/aeabi_memset-soft.S %D%/aeabi_memclr.c \
>> + %D%/tls.c %D%/set_tls.c %D%/read_tp.S \
>> %D%/memchr-stub.c \
>> %D%/memchr.S \
>> %D%/memcpy-stub.c \
>> diff --git a/newlib/libc/machine/arm/arm_tls.h b/newlib/libc/machine/arm/arm_tls.h
>> new file mode 100644
>> index 000000000..0a7421d68
>> --- /dev/null
>> +++ b/newlib/libc/machine/arm/arm_tls.h
>> @@ -0,0 +1,60 @@
>> +/*
>> + * SPDX-License-Identifier: BSD-3-Clause
>> + *
>> + * Copyright © 2020 Keith Packard
>> + *
>> + * Redistribution and use in source and binary forms, with or without
>> + * modification, are permitted provided that the following conditions
>> + * are met:
>> + *
>> + * 1. Redistributions of source code must retain the above copyright
>> + * notice, this list of conditions and the following disclaimer.
>> + *
>> + * 2. Redistributions in binary form must reproduce the above
>> + * copyright notice, this list of conditions and the following
>> + * disclaimer in the documentation and/or other materials provided
>> + * with the distribution.
>> + *
>> + * 3. Neither the name of the copyright holder nor the names of its
>> + * contributors may be used to endorse or promote products derived
>> + * from this software without specific prior written permission.
>> + *
>> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
>> + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
>> + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
>> + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
>> + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
>> + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
>> + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
>> + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
>> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
>> + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
>> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
>> + * OF THE POSSIBILITY OF SUCH DAMAGE.
>> + */
>> +
>> +#if ((__ARM_FEATURE_COPROC & 1) || __ARM_ARCH >= 8) && __ARM_ARCH_PROFILE != 'M' && __ARM_ARCH >= 6
>> +#define ARM_TLS_CP15
>> +#endif
>> +
>> +/* Switch cortex-m0 to use RP2040 CPUID register if requested */
>> +#ifdef __THREAD_LOCAL_STORAGE_RP2040
>> +#define ARM_RP2040
>> +#endif
>> +
>> +#ifdef ARM_RP2040
>> +#define RP2040_SIO_BASE 0xd0000000
>> +#define RP2040_CPUID (RP2040_SIO_BASE + 0)
>> +#define ARM_TLS_COUNT 2
>> +#else
>> +#define ARM_TLS_COUNT 1
>> +#endif
>> +
>> +#ifndef _IN_ASM
>> +/* This needs to be global so that __aeabi_read_tp can
>> + * refer to it in an asm statement
>> + */
>> +#ifndef ARM_TLS_CP15
>> +extern void *__tls[ARM_TLS_COUNT];
>> +#endif
>> +#endif
>> diff --git a/newlib/libc/machine/arm/read_tp.S b/newlib/libc/machine/arm/read_tp.S
>> new file mode 100644
>> index 000000000..811e073f8
>> --- /dev/null
>> +++ b/newlib/libc/machine/arm/read_tp.S
>> @@ -0,0 +1,98 @@
>> +/*
>> + * SPDX-License-Identifier: BSD-3-Clause
>> + *
>> + * Copyright © 2020 Keith Packard
>> + * Copyright © 2024 Stephen Street
>> + *
>> + * Redistribution and use in source and binary forms, with or without
>> + * modification, are permitted provided that the following conditions
>> + * are met:
>> + *
>> + * 1. Redistributions of source code must retain the above copyright
>> + * notice, this list of conditions and the following disclaimer.
>> + *
>> + * 2. Redistributions in binary form must reproduce the above
>> + * copyright notice, this list of conditions and the following
>> + * disclaimer in the documentation and/or other materials provided
>> + * with the distribution.
>> + *
>> + * 3. Neither the name of the copyright holder nor the names of its
>> + * contributors may be used to endorse or promote products derived
>> + * from this software without specific prior written permission.
>> + *
>> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
>> + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
>> + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
>> + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
>> + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
>> + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
>> + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
>> + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
>> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
>> + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
>> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
>> + * OF THE POSSIBILITY OF SUCH DAMAGE.
>> + */
>> +#include <newlib.h>
>> +
>> +#ifdef __THREAD_LOCAL_STORAGE
>> +
>> +#define _IN_ASM
>> +#include "arm_tls.h"
>> +/*
>> + * This cannot be a C ABI function as the compiler assumes that it
>> + * does not modify anything other than r0 and lr.
>> + */
>> + .syntax unified
>> + .section .text.__aeabi_read_tp
>> + .align 4
>> + .p2align 4,,15
>> + .global __aeabi_read_tp
>> + .type __aeabi_read_tp,%function
>> +#ifdef __thumb__
>> + .thumb
>> +#endif
>> +
>> +__aeabi_read_tp:
>> + .cfi_sections .debug_frame
>> + .cfi_startproc
>> +
>> +#ifdef ARM_TLS_CP15
>> + mrc p15, 0, r0, c13, c0, 3
>> + bx lr
>> +#else
>> +
>> +#ifdef ARM_RP2040
>> +
>> + /*
>> + * Code for RP2040 processor. This is a dual-core cortex-m0
>> + * design. We use the CPUID register, stored at offset zero of
>> + * the Single-cycle IO block at 0xd0000000
>> + */
>> +
>> +#define TLS_SIZE (4 * RP2040_NCORE)
>> +
>> + push {r1,lr} /* Save R1 (and LR) */
>> + ldr r1,=0xd0000000 /* Address of SIO->CPUID */
>> + ldr r1,[r1] /* Fetch active core */
>> + lsls r1,r1,#2 /* Multiply by 4 */
>> + ldr r0,=__tls /* Address of __tls array */
>> + ldr r0,[r0,r1] /* Fetch __tls[CPUID] */
>> + pop {r1,pc} /* Restore R1 and return */
>> +
>> +#else
>> +
>> +#define TLS_SIZE 4
>> +
>> + ldr r0,=__tls /* Load the address of __tls */
>> + ldr r0,[r0] /* Dereference to get the value of __tls */
>> + bx lr /* All done, return to caller */
>> +
>> +#endif
>> +
>> +#endif
>> +
>> + .cfi_endproc
>> +
>> +#endif
>> +
>> diff --git a/newlib/libc/machine/arm/set_tls.c b/newlib/libc/machine/arm/set_tls.c
>> new file mode 100644
>> index 000000000..fd3e940f6
>> --- /dev/null
>> +++ b/newlib/libc/machine/arm/set_tls.c
>> @@ -0,0 +1,79 @@
>> +/*
>> + * SPDX-License-Identifier: BSD-3-Clause
>> + *
>> + * Copyright © 2019 Keith Packard
>> + * Copyright © 2024 Stephen Street
>> + *
>> + * Redistribution and use in source and binary forms, with or without
>> + * modification, are permitted provided that the following conditions
>> + * are met:
>> + *
>> + * 1. Redistributions of source code must retain the above copyright
>> + * notice, this list of conditions and the following disclaimer.
>> + *
>> + * 2. Redistributions in binary form must reproduce the above
>> + * copyright notice, this list of conditions and the following
>> + * disclaimer in the documentation and/or other materials provided
>> + * with the distribution.
>> + *
>> + * 3. Neither the name of the copyright holder nor the names of its
>> + * contributors may be used to endorse or promote products derived
>> + * from this software without specific prior written permission.
>> + *
>> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
>> + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
>> + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
>> + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
>> + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
>> + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
>> + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
>> + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
>> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
>> + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
>> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
>> + * OF THE POSSIBILITY OF SUCH DAMAGE.
>> + */
>> +
>> +#include <picotls.h>
>> +#include <string.h>
>> +#include <stdint.h>
>> +
>> +#ifdef __THREAD_LOCAL_STORAGE_API
>> +
>> +#include "arm_tls.h"
>> +
>> +/* This needs to be global so that __aeabi_read_tp can
>> + * refer to it in an asm statement
>> + */
>> +#ifndef ARM_TLS_CP15
>> +extern void *__tls[];
>> +#endif
>> +
>> +/* The size of the thread control block.
>> + * TLS relocations are generated relative to
>> + * a location this far *before* the first thread
>> + * variable (!)
>> + * NB: The actual size before tp also includes padding
>> + * to align up to the alignment of .tdata/.tbss.
>> + */
>> +#define TCB_SIZE 8
>> +extern char __arm32_tls_tcb_offset;
>> +#define TP_OFFSET ((size_t)&__arm32_tls_tcb_offset)
>> +
>> +void
>> +_set_tls(void *tls)
>> +{
>> + tls = (uint8_t *)tls - TP_OFFSET;
>> +#ifdef ARM_TLS_CP15
>> + __asm__("mcr p15, 0, %0, cr13, cr0, 3" : : "r"(tls));
>> +#else
>> +#ifdef ARM_RP2040
>> + uint32_t cpuid = *(uint32_t *)0xd0000000;
>> + __tls[cpuid] = tls;
>> +#else
>> + __tls[0] = tls;
>> +#endif
>> +#endif
>> +}
>> +
>> +#endif
>> diff --git a/newlib/libc/machine/arm/tls.c b/newlib/libc/machine/arm/tls.c
>> new file mode 100644
>> index 000000000..156b9d72a
>> --- /dev/null
>> +++ b/newlib/libc/machine/arm/tls.c
>> @@ -0,0 +1,52 @@
>> +/*
>> + * SPDX-License-Identifier: BSD-3-Clause
>> + *
>> + * Copyright © 2019 Keith Packard
>> + * Copyright © 2024 Stephen Street
>> + *
>> + * Redistribution and use in source and binary forms, with or without
>> + * modification, are permitted provided that the following conditions
>> + * are met:
>> + *
>> + * 1. Redistributions of source code must retain the above copyright
>> + * notice, this list of conditions and the following disclaimer.
>> + *
>> + * 2. Redistributions in binary form must reproduce the above
>> + * copyright notice, this list of conditions and the following
>> + * disclaimer in the documentation and/or other materials provided
>> + * with the distribution.
>> + *
>> + * 3. Neither the name of the copyright holder nor the names of its
>> + * contributors may be used to endorse or promote products derived
>> + * from this software without specific prior written permission.
>> + *
>> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
>> + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
>> + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
>> + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
>> + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
>> + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
>> + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
>> + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
>> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
>> + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
>> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
>> + * OF THE POSSIBILITY OF SUCH DAMAGE.
>> + */
>> +
>> +#include <picotls.h>
>> +#include <string.h>
>> +#include <stdint.h>
>> +
>> +#ifdef __THREAD_LOCAL_STORAGE
>> +
>> +#include "arm_tls.h"
>> +
>> +/* This needs to be global so that __aeabi_read_tp can
>> + * refer to it in an asm statement
>> + */
>> +#ifndef ARM_TLS_CP15
>> +void *__tls[ARM_TLS_COUNT];
>> +#endif
>> +
>> +#endif
>> diff --git a/newlib/libc/misc/Makefile.inc b/newlib/libc/misc/Makefile.inc
>> index 78bb022dd..1abd05295 100644
>> --- a/newlib/libc/misc/Makefile.inc
>> +++ b/newlib/libc/misc/Makefile.inc
>> @@ -2,6 +2,7 @@ libc_a_SOURCES += \
>> %D%/__dprintf.c \
>> %D%/unctrl.c \
>> %D%/ffs.c \
>> + %D%/inittls.c \
>> %D%/init.c \
>> %D%/fini.c
>> diff --git a/newlib/libc/misc/inittls.c b/newlib/libc/misc/inittls.c
>> new file mode 100644
>> index 000000000..458013fbb
>> --- /dev/null
>> +++ b/newlib/libc/misc/inittls.c
>> @@ -0,0 +1,77 @@
>> +/*
>> + * SPDX-License-Identifier: BSD-3-Clause
>> + *
>> + * Copyright © 2019 Keith Packard
>> + *
>> + * Redistribution and use in source and binary forms, with or without
>> + * modification, are permitted provided that the following conditions
>> + * are met:
>> + *
>> + * 1. Redistributions of source code must retain the above copyright
>> + * notice, this list of conditions and the following disclaimer.
>> + *
>> + * 2. Redistributions in binary form must reproduce the above
>> + * copyright notice, this list of conditions and the following
>> + * disclaimer in the documentation and/or other materials provided
>> + * with the distribution.
>> + *
>> + * 3. Neither the name of the copyright holder nor the names of its
>> + * contributors may be used to endorse or promote products derived
>> + * from this software without specific prior written permission.
>> + *
>> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
>> + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
>> + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
>> + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
>> + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
>> + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
>> + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
>> + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
>> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
>> + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
>> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
>> + * OF THE POSSIBILITY OF SUCH DAMAGE.
>> + */
>> +
>> +#include <picotls.h>
>> +#include <string.h>
>> +#include <stdint.h>
>> +
>> +#ifdef __THREAD_LOCAL_STORAGE_API
>> +
>> +/*
>> + * The TLS block consists of initialized data immediately followed by
>> + * zero filled data
>> + *
>> + * These addresses must be defined by the loader configuration file
>> + */
>> +
>> +extern char __tdata_source[]; /* Source of TLS initialization data (in ROM) */
>> +
>> +#ifdef __PICOCRT_RUNTIME_SIZE
>> +extern char __tdata_start[]; /* Start of static tdata area */
>> +extern char __tdata_end[]; /* End of static tdata area */
>> +extern char __tbss_start[]; /* Start of static zero-initialized TLS data */
>> +extern char __tbss_end[]; /* End of static zero-initialized TLS data */
>> +#define __tdata_size (__tdata_end - __tdata_start)
>> +#define __tbss_size (__tbss_end - __tbss_start)
>> +#define __tbss_offset (__tbss_start - __tdata_start)
>> +#else
>> +extern char __tdata_size[]; /* Size of TLS initized data */
>> +extern char __tbss_size[]; /* Size of TLS zero-filled data */
>> +extern char __tbss_offset[]; /* Offset from tdata to tbss */
>> +#endif
>> +
>> +void
>> +_init_tls(void *__tls)
>> +{
>> + char *tls = __tls;
>> +
>> + /* Copy tls initialized data */
>> + memcpy(tls, __tdata_source, (uintptr_t)__tdata_size);
>> +
>> + /* Clear tls zero data */
>> + memset(tls + (uintptr_t)__tbss_offset, '\0', (uintptr_t)__tbss_size);
>> +}
>> +
>> +#endif
>> diff --git a/newlib/libc/sys/arm/crt0.S b/newlib/libc/sys/arm/crt0.S
>> index 51e86d549..ea2122d93 100644
>> --- a/newlib/libc/sys/arm/crt0.S
>> +++ b/newlib/libc/sys/arm/crt0.S
>> @@ -375,6 +375,15 @@ __change_mode:
>> #endif
>>
>> bl FUNCTION (memset)
>> +
>> +#ifdef __THREAD_LOCAL_STORAGE
>> + /* Initialize TLS in local-exec mode. */
>> + ldr a1, .LCtls_base /* First arg: TLS block. */
>> + bl FUNCTION (_init_tls)
>> + ldr a1, .LCtls_base /* First arg: TLS block. */
>> + bl FUNCTION (_set_tls)
>> +#endif
>> +
>> #if !defined (ARM_RDP_MONITOR) && !defined (ARM_RDI_MONITOR)
>> /* Changes by toralf: Taken from libgloss/m68k/crt0.S
>> initialize target specific stuff. Only execute these
>> @@ -598,6 +607,10 @@ change_back:
>> .word __bss_start__
>> .LC2:
>> .word __bss_end__
>> +#ifdef __THREAD_LOCAL_STORAGE
>> +.LCtls_base:
>> + .word __tls_base
>> +#endif
>> #ifdef __USES_INITFINI__
>> #ifdef _LITE_EXIT
>> .Latexit:
>> diff --git a/newlib/newlib.hin b/newlib/newlib.hin
>> index 52cd500db..350762f2f 100644
>> --- a/newlib/newlib.hin
>> +++ b/newlib/newlib.hin
>> @@ -420,6 +420,12 @@
>> _reent members. */
>> #undef _WANT_REENT_THREAD_LOCAL
>> +/* Define to enable the TLS runtime API. */
>> +#undef __THREAD_LOCAL_STORAGE
>> +
>> +/* Define to enable the TLS runtime API. */
>> +#undef __THREAD_LOCAL_STORAGE_API
>> +
>> /* Register application finalization function using atexit. */
>> #undef _WANT_REGISTER_FINI
>
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