esp-idf/components/newlib/platform_include/esp_newlib.h
Ivan Grokhotkov b7b9ea4361 newlib: add _RETARGETABLE_LOCKING support
This adds support for the retargetable locking implementation in
newlib 3. This feature will be enabled in the future toolchain builds.
With the present version of the toolchain, this code doesn't get used.

When _RETARGETABLE_LOCKING gets enabled, newlib locking implementation
will be modified as follows:

- Legacy ESP-specific _lock_xxx functions are preserved. This is done
  because ROM copies of newlib in ESP32 and ESP32-S2 rely on these
  functions through the function pointer table. Also there is some
  code in IDF which still uses these locking functions.

- New __retarget_lock_xxx functions are introduced. Newlib expects
  these functions to be provided by the system. These functions work
  pretty much the same way as the ESP-specific _lock_xxx functions,
  except one major difference: _lock_acquire receives the lock pointer
  by value, and as such doesn't support lazy initialization.

- Static locks used by newlib are now explicitly initialized at
  startup. Since it is unlikely that these static locks are used at
  the same time, all compatible locks are set to point to the same
  mutex. This saves a bit of RAM. Note that there are still many locks
  not initialized statically, in particular those inside FILE
  structures.
2020-12-29 16:18:04 +01:00

62 lines
1.5 KiB
C

// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef __ESP_NEWLIB_H__
#define __ESP_NEWLIB_H__
#include <sys/reent.h>
/*
* Initialize newlib time functions
*/
void esp_newlib_time_init(void);
/**
* Replacement for newlib's _REENT_INIT_PTR and __sinit.
*
* Called from startup code and FreeRTOS, not intended to be called from
* application code.
*/
void esp_reent_init(struct _reent* r);
/**
* Clean up some of lazily allocated buffers in REENT structures.
*/
void esp_reent_cleanup(void);
/**
* Function which sets up syscall table used by newlib functions in ROM.
*
* Called from the startup code, not intended to be called from application
* code.
*/
void esp_setup_syscall_table(void);
/**
* Update current microsecond time from RTC
*/
void esp_set_time_from_rtc(void);
/*
* Sync counters RTC and FRC. Update boot_time.
*/
void esp_sync_counters_rtc_and_frc(void);
/**
* Initialize newlib static locks
*/
void esp_newlib_locks_init(void);
#endif //__ESP_NEWLIB_H__