Nothing Special / mbed-STM32F103C8

Modification of Mbed-dev library for LQFP48 package microcontrollers: STM32F103C8 (STM32F103C8T6) and STM32F103CB (STM32F103CBT6) (Bluepill boards, Maple mini etc. )

Fork of mbed-STM32F103C8_org by Nothing Special

Library for STM32F103C8 (Bluepill boards etc.).
Use this instead of mbed library.
This library allows the size of the code in the FLASH up to 128kB. Therefore, code also runs on microcontrollers STM32F103CB (eg. Maple mini).
But in the case of STM32F103C8, check the size of the resulting code would not exceed 64kB.

To compile a program with this library, use NUCLEO-F103RB as the target name. !

Changes:

  • Corrected initialization of the HSE + crystal clock (mbed permanent bug), allowing the use of on-board xtal (8MHz).(1)
  • Additionally, it also set USB clock (48Mhz).(2)
  • Definitions of pins and peripherals adjusted to LQFP48 case.
  • Board led LED1 is now PC_13 (3)
  • USER_BUTTON is now PC_14 (4)

    Now the library is complete rebuilt based on mbed-dev v160 (and not yet fully tested).

notes
(1) - In case 8MHz xtal on board, CPU frequency is 72MHz. Without xtal is 64MHz.
(2) - Using the USB interface is only possible if STM32 is clocking by on-board 8MHz xtal or external clock signal 8MHz on the OSC_IN pin.
(3) - On Bluepill board led operation is reversed, i.e. 0 - led on, 1 - led off.
(4) - Bluepill board has no real user button

Information

After export to SW4STM (AC6):

  • add line #include "mbed_config.h" in files Serial.h and RawSerial.h
  • in project properties change Optimisation Level to Optimise for size (-Os)

platform/mbed_critical.c

Committer:
mega64
Date:
2017-04-27
Revision:
148:8b0b02bf146f
Parent:
146:03e976389d16

File content as of revision 148:8b0b02bf146f:

/*
 * Copyright (c) 2015-2016, ARM Limited, All Rights Reserved
 * SPDX-License-Identifier: Apache-2.0
 *
 * 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.
 */

/* Declare __STDC_LIMIT_MACROS so stdint.h defines UINT32_MAX when using C++ */
#define __STDC_LIMIT_MACROS
#include "platform/mbed_critical.h"

#include "cmsis.h"
#include "platform/mbed_assert.h"
#include "platform/mbed_toolchain.h"

#define EXCLUSIVE_ACCESS (!defined (__CORTEX_M0) && !defined (__CORTEX_M0PLUS))

static volatile uint32_t interrupt_enable_counter = 0;
static volatile bool critical_interrupts_disabled = false;

bool core_util_are_interrupts_enabled(void)
{
#if defined(__CORTEX_A9)
    return ((__get_CPSR() & 0x80) == 0);
#else
    return ((__get_PRIMASK() & 0x1) == 0);
#endif
}

MBED_WEAK void core_util_critical_section_enter(void)
{
    bool interrupts_disabled = !core_util_are_interrupts_enabled();
    __disable_irq();

    /* Save the interrupt disabled state as it was prior to any nested critical section lock use */
    if (!interrupt_enable_counter) {
        critical_interrupts_disabled = interrupts_disabled;
    }

    /* If the interrupt_enable_counter overflows or we are in a nested critical section and interrupts
       are enabled, then something has gone badly wrong thus assert an error.
    */
    MBED_ASSERT(interrupt_enable_counter < UINT32_MAX); 
// FIXME
#ifndef   FEATURE_UVISOR
    if (interrupt_enable_counter > 0) {
        MBED_ASSERT(interrupts_disabled);
    }
#else
#warning "core_util_critical_section_enter needs fixing to work from unprivileged code"
#endif /* FEATURE_UVISOR */
    interrupt_enable_counter++;
}

MBED_WEAK void core_util_critical_section_exit(void)
{
    /* If critical_section_enter has not previously been called, do nothing */
    if (interrupt_enable_counter) {

// FIXME
#ifndef   FEATURE_UVISOR
        bool interrupts_disabled = !core_util_are_interrupts_enabled(); /* get the current interrupt disabled state */

        MBED_ASSERT(interrupts_disabled); /* Interrupts must be disabled on invoking an exit from a critical section */
#else
#warning "core_util_critical_section_exit needs fixing to work from unprivileged code"
#endif /* FEATURE_UVISOR */

        interrupt_enable_counter--;

        /* Only re-enable interrupts if we are exiting the last of the nested critical sections and
           interrupts were enabled on entry to the first critical section.
        */
        if (!interrupt_enable_counter && !critical_interrupts_disabled) {
            __enable_irq();
        }
    }
}

#if EXCLUSIVE_ACCESS

/* Supress __ldrex and __strex deprecated warnings - "#3731-D: intrinsic is deprecated" */
#if defined (__CC_ARM) 
#pragma diag_suppress 3731
#endif

bool core_util_atomic_cas_u8(uint8_t *ptr, uint8_t *expectedCurrentValue, uint8_t desiredValue)
{
    uint8_t currentValue = __LDREXB((volatile uint8_t*)ptr);
    if (currentValue != *expectedCurrentValue) {
        *expectedCurrentValue = currentValue;
        __CLREX();
        return false;
    }

    return !__STREXB(desiredValue, (volatile uint8_t*)ptr);
}

bool core_util_atomic_cas_u16(uint16_t *ptr, uint16_t *expectedCurrentValue, uint16_t desiredValue)
{
    uint16_t currentValue = __LDREXH((volatile uint16_t*)ptr);
    if (currentValue != *expectedCurrentValue) {
        *expectedCurrentValue = currentValue;
        __CLREX();
        return false;
    }

    return !__STREXH(desiredValue, (volatile uint16_t*)ptr);
}


bool core_util_atomic_cas_u32(uint32_t *ptr, uint32_t *expectedCurrentValue, uint32_t desiredValue)
{
    uint32_t currentValue = __LDREXW((volatile uint32_t*)ptr);
    if (currentValue != *expectedCurrentValue) {
        *expectedCurrentValue = currentValue;
        __CLREX();
        return false;
    }

    return !__STREXW(desiredValue, (volatile uint32_t*)ptr);
}

uint8_t core_util_atomic_incr_u8(uint8_t *valuePtr, uint8_t delta)
{
    uint8_t newValue;
    do {
        newValue = __LDREXB((volatile uint8_t*)valuePtr) + delta;
    } while (__STREXB(newValue, (volatile uint8_t*)valuePtr));
    return newValue;
}

uint16_t core_util_atomic_incr_u16(uint16_t *valuePtr, uint16_t delta)
{
    uint16_t newValue;
    do {
        newValue = __LDREXH((volatile uint16_t*)valuePtr) + delta;
    } while (__STREXH(newValue, (volatile uint16_t*)valuePtr));
    return newValue;
}

uint32_t core_util_atomic_incr_u32(uint32_t *valuePtr, uint32_t delta)
{
    uint32_t newValue;
    do {
        newValue = __LDREXW((volatile uint32_t*)valuePtr) + delta;
    } while (__STREXW(newValue, (volatile uint32_t*)valuePtr));
    return newValue;
}


uint8_t core_util_atomic_decr_u8(uint8_t *valuePtr, uint8_t delta)
{
    uint8_t newValue;
    do {
        newValue = __LDREXB((volatile uint8_t*)valuePtr) - delta;
    } while (__STREXB(newValue, (volatile uint8_t*)valuePtr));
    return newValue;
}

uint16_t core_util_atomic_decr_u16(uint16_t *valuePtr, uint16_t delta)
{
    uint16_t newValue;
    do {
        newValue = __LDREXH((volatile uint16_t*)valuePtr) - delta;
    } while (__STREXH(newValue, (volatile uint16_t*)valuePtr));
    return newValue;
}

uint32_t core_util_atomic_decr_u32(uint32_t *valuePtr, uint32_t delta)
{
    uint32_t newValue;
    do {
        newValue = __LDREXW((volatile uint32_t*)valuePtr) - delta;
    } while (__STREXW(newValue, (volatile uint32_t*)valuePtr));
    return newValue;
}

#else

bool core_util_atomic_cas_u8(uint8_t *ptr, uint8_t *expectedCurrentValue, uint8_t desiredValue)
{
    bool success;
    uint8_t currentValue;
    core_util_critical_section_enter();
    currentValue = *ptr;
    if (currentValue == *expectedCurrentValue) {
        *ptr = desiredValue;
        success = true;
    } else {
        *expectedCurrentValue = currentValue;
        success = false;
    }
    core_util_critical_section_exit();
    return success;
}

bool core_util_atomic_cas_u16(uint16_t *ptr, uint16_t *expectedCurrentValue, uint16_t desiredValue)
{
    bool success;
    uint16_t currentValue;
    core_util_critical_section_enter();
    currentValue = *ptr;
    if (currentValue == *expectedCurrentValue) {
        *ptr = desiredValue;
        success = true;
    } else {
        *expectedCurrentValue = currentValue;
        success = false;
    }
    core_util_critical_section_exit();
    return success;
}


bool core_util_atomic_cas_u32(uint32_t *ptr, uint32_t *expectedCurrentValue, uint32_t desiredValue)
{
    bool success;
    uint32_t currentValue;
    core_util_critical_section_enter();
    currentValue = *ptr;
    if (currentValue == *expectedCurrentValue) {
        *ptr = desiredValue;
        success = true;
    } else {
        *expectedCurrentValue = currentValue;
        success = false;
    }
    core_util_critical_section_exit();
    return success;
}


uint8_t core_util_atomic_incr_u8(uint8_t *valuePtr, uint8_t delta)
{
    uint8_t newValue;
    core_util_critical_section_enter();
    newValue = *valuePtr + delta;
    *valuePtr = newValue;
    core_util_critical_section_exit();
    return newValue;
}

uint16_t core_util_atomic_incr_u16(uint16_t *valuePtr, uint16_t delta)
{
    uint16_t newValue;
    core_util_critical_section_enter();
    newValue = *valuePtr + delta;
    *valuePtr = newValue;
    core_util_critical_section_exit();
    return newValue;
}

uint32_t core_util_atomic_incr_u32(uint32_t *valuePtr, uint32_t delta)
{
    uint32_t newValue;
    core_util_critical_section_enter();
    newValue = *valuePtr + delta;
    *valuePtr = newValue;
    core_util_critical_section_exit();
    return newValue;
}


uint8_t core_util_atomic_decr_u8(uint8_t *valuePtr, uint8_t delta)
{
    uint8_t newValue;
    core_util_critical_section_enter();
    newValue = *valuePtr - delta;
    *valuePtr = newValue;
    core_util_critical_section_exit();
    return newValue;
}

uint16_t core_util_atomic_decr_u16(uint16_t *valuePtr, uint16_t delta)
{
    uint16_t newValue;
    core_util_critical_section_enter();
    newValue = *valuePtr - delta;
    *valuePtr = newValue;
    core_util_critical_section_exit();
    return newValue;
}

uint32_t core_util_atomic_decr_u32(uint32_t *valuePtr, uint32_t delta)
{
    uint32_t newValue;
    core_util_critical_section_enter();
    newValue = *valuePtr - delta;
    *valuePtr = newValue;
    core_util_critical_section_exit();
    return newValue;
}

#endif


bool core_util_atomic_cas_ptr(void **ptr, void **expectedCurrentValue, void *desiredValue) {
    return core_util_atomic_cas_u32(
            (uint32_t *)ptr,
            (uint32_t *)expectedCurrentValue,
            (uint32_t)desiredValue);
}

void *core_util_atomic_incr_ptr(void **valuePtr, ptrdiff_t delta) {
    return (void *)core_util_atomic_incr_u32((uint32_t *)valuePtr, (uint32_t)delta);
}

void *core_util_atomic_decr_ptr(void **valuePtr, ptrdiff_t delta) {
    return (void *)core_util_atomic_decr_u32((uint32_t *)valuePtr, (uint32_t)delta);
}