/* ----> DO NOT REMOVE THE FOLLOWING NOTICE <---- * * Copyright (c) 2014-2015 Datalight, Inc. * All Rights Reserved Worldwide. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; use version 2 of the License. * * This program is distributed in the hope that it will be useful, * but "AS-IS," WITHOUT ANY WARRANTY; without even the implied warranty * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ /* Businesses and individuals that for commercial or other reasons cannot * comply with the terms of the GPLv2 license may obtain a commercial license * before incorporating Reliance Edge into proprietary software for * distribution in any form. Visit http://www.datalight.com/reliance-edge for * more information. */ /** @file * @brief Macros to encapsulate MISRA C:2012 deviations in OS-specific code. */ #ifndef REDOSDEVIATIONS_H #define REDOSDEVIATIONS_H #if REDCONF_OUTPUT == 1 /* Needed for PRINT_ASSERT() and OUTPUT_CHARACTER(). */ #include #endif #if ( REDCONF_ASSERTS == 1 ) && ( REDCONF_OUTPUT == 1 ) /** Print a formatted message for an assertion. * * Usages of this macro deviate from MISRA C:2012 Rule 21.6 (required). Using * printf() is the most convenient way to output this information; and the risk * of "unspecified, undefined and implementation-defined" behavior causing * problems (as cited in the rationale for the rule) is small. The driver does * not depend on this string being outputted correctly. Furthermore, use of * printf() disappears when either asserts or output are disabled. * * As Rule 21.6 is required, a separate deviation record is required. */ #define PRINT_ASSERT( file, line ) \ printf( "Assertion failed in \"%s\" at line %u\n\r", ( ( file ) == NULL ) ? "" : ( file ), ( unsigned ) ( line ) ) #endif /** Cast a value to unsigned long. * * Usages of this macro deviate from MISRA C:2012 Directive 4.6. This macro is * used in two places to cast a uint64_t value (used by the block device * abstraction for sector numbers) to unsigned long, since third-party code * which is not under the control of this project uses unsigned long for sector * numbers. The cast is guaranteed to not lose any information, since when the * disk is opened the sector count is verified to be less than or equal to an * unsigned long value. The text of the directive mentions that "it might be * desirable not to apply this guideline when interfacing with ... code outside * the project's control", which describes the situation for this deviation. * * As Directive 4.6 is advisory, a deviation record is not required. This * notice is the only record of the deviation. */ #define CAST_ULONG( ull ) ( ( unsigned long ) ( ull ) ) /** Cast a const-qualified pointer to a pointer which is *not* const-qualified. * * Usages of this macro deviate from MISRA C:2012 Rule 11.8. This macro is * used in exactly one place in order to cope with a poorly designed * third-party interface. Reliance Edge, at every level of the stack, uses * const-qualified pointers for buffers used in write operations, since the * data is read from the buffer, and the buffer does not need to be modified * (consistent with Rule 8.13). One of the third-party block device interfaces * that Reliance Edge interfaces with does not follow this convention: it uses * an unqualified pointer for the buffer parameter of its sector write * function. This forces the need for the cast to avoid warnings. The * implementation of the sector write function is provided by the user, so it * is to be hoped that the buffer is not actually modified. * * As Rule 11.8 is required, a separate deviation record is required. */ #define CAST_AWAY_CONST( type, ptr ) ( ( type * ) ( ptr ) ) /** Allocate zero-initialized (cleared) memory. * * All usages of this macro deviate from MISRA C:2012 Directive 4.12 (required) * and Rule 21.3 (required). In the context of the single place it is actually * used, this macro also deviates from Rule 22.1 (required). * * This macro is used in the FreeRTOS block device code in order to allocate a * RAM disk, when that implementation of the block device is selected. The * primary rationale for all these deviations is that a) the RAM disk cannot be * allocated statically (since the volume information is stored in a * structure), and b) the RAM disk is primarily intended as a temporary testing * tool for users who want to try out Reliance Edge before the real storage * media is available. In most real systems, Reliance Edge is used with * non-volatile storage like SD/MMC or eMMC, not with RAM disks. * * Rule 22.1 states that all resources which are allocated must also be * explicitly freed. The RAM disk is allocated and never freed, deviating from * that rule. This is done because the data in the RAM disk is emulating a * non-volatile storage medium, and thus needs to persist even after the block * device is closed, to allow the file system to be formatted and then mounted, * or unmounted and remounted in the course of a test. Thus the memory will * remain allocated until the target device is rebooted. This is assumed to be * acceptable for the primary purpose of the RAM disk, which is preliminary * testing. * * As Directive 4.12, Rule 21.3, and Rule 22.1 are all required, separate * deviation records are required. */ #define ALLOCATE_CLEARED_MEMORY( nelem, elsize ) calloc( nelem, elsize ) #if REDCONF_OUTPUT == 1 /** Output a character to a serial port or other display device. * * Usages of this macro deviate from MISRA C:2012 Rule 21.6 (required). * FreeRTOS does not include a standard method of printing characters, so * putchar() is the most convenient and portable way to accomplish the task. * The risk of "unspecified, undefined and implementation-defined" behavior * causing problems (as cited in the rationale for the rule) is small. The * driver does not depend on the character being outputted correctly. * Furthermore, use of putchar() disappears when output is disabled. * * As Rule 21.6 is required, a separate deviation record is required. */ #define OUTPUT_CHARACTER( ch ) ( void ) putchar( ch ) #endif #if ( REDCONF_TASK_COUNT > 1U ) && ( REDCONF_API_POSIX == 1 ) /** Cast a TaskHandle_t (a pointer type) to uintptr_t. * * Usage of this macro deviate from MISRA-C:2012 Rule 11.4 (advisory). This * macro is used for the FreeRTOS version of RedOsTaskId(). Some RTOSes * natively use an integer for task IDs; others use pointers. RedOsTaskId() * uses integers, FreeRTOS uses pointers; to reconcile this difference, the * pointer must be cast to integer. This is fairly safe, since the resulting * integer is never cast back to a pointer; and although the integer * representation of a pointer is implementation-defined, the representation is * irrelevant provided that unique pointers are converted to unique integers. * * As Rule 11.4 is advisory, a deviation record is not required. This notice * is the only record of the deviation. */ #define CAST_TASK_PTR_TO_UINTPTR( taskptr ) ( ( uintptr_t ) ( taskptr ) ) #endif /** Ignore the return value of a function (cast to void) * * Usages of this macro deviate from MISRA C:2012 Directive 4.7, which states * that error information must be checked immediately after a function returns * potential error information. * * If asserts and output are enabled, then this macro is used to document that * the return value of printf() is ignored. A failure of printf() does not * impact the filesystem core, nor is there anything the filesystem can do to * respond to such an error (especially since it occurs within an assert). * Thus, the most reasonable action is to ignore the error. * * In the STM32 SDIO block device implementation, errors are also ignored in an * IRQ interrupt handler. This is the most reasonable action to take for two * reasons: (a) it would be dangerous to spend processor time responding to the * error inside the IRQ handler; (b) it has been verified that the same error * is propagated to the DiskRead/Write method, which does return the error to * the core. * * In the Atmel SD/MMC block device implementation, error information from * sd_mmc_read_capacity() is ignored. This is a reasonable action because all * of the possible error conditions were eliminated by a previous check. * sd_mmc_read_capacity() fails under the same conditions as * sd_mmc_test_unit_ready(), which was checked earlier in the same function. * * In the mutex module, error information returned from the mutex release * function is ignored when asserts are disabled. This is a reasonable action * because the mutex release function (xSemaphoreGive) is documented only to * fail if the mutex was not obtained correctly, which can be demonstrably * avoided. * * As Directive 4.7 is required, a separate deviation record is required. */ #define IGNORE_ERRORS( fn ) ( ( void ) ( fn ) ) /** @brief Determine whether a pointer is aligned on a 32-bit boundary. * * This is used to determine whether a data buffer meets the requirements of * the underlying block device implementation. When transferring data via * DMA (Direct Memory Access) on an STM32 device, the data buffer must be cast * as a uint32 pointer, and unexpected behavior may occur if the buffer is not * aligned correctly. * * There is no way to perform this check without deviating from MISRA C rules * against casting pointers to integer types. Usage of this macro deviates * from MISRA C:2012 Rule 11.4 (advisory). The main rationale the rule cites * against converting pointers to integers is that the chosen integer type may * not be able to represent the pointer; this is a non-issue here since we use * uintptr_t. The text says the rule still applies when using uintptr_t due to * concern about unaligned pointers, but that is not an issue here since the * integer value of the pointer is not saved and not converted back into a * pointer and dereferenced. The result of casting a pointer to a sufficiently * large integer is implementation-defined, but macros similar to this one have * been used by Datalight for a long time in a wide variety of environments and * they have always worked as expected. * * This deviation only occurs when using the STM32 SDIO block device * implementation. * * As Rule 11.4 is advisory, a deviation record is not required. This notice * is the only record of deviation. */ #define IS_UINT32_ALIGNED_PTR( ptr ) ( ( ( uintptr_t ) ( ptr ) & ( sizeof( uint32_t ) - 1U ) ) == 0U ) /** @brief Cast a 32-bit aligned void pointer to a uint32 pointer. * * Usages of this macro deviate from MISRA C:2012 Rule 11.5 (advisory). A * cast from a void pointer to an object pointer is discouraged because of * potential alignment issues. However, this macro is only used to cast * pointers that have already been tested to be 32-bit aligned, so the * operation will be safe. * * This deviation only occurs when using the STM32 SDIO block device * implementation. * * As rule 11.5 is advisory, a deviation record is not required. This notice * is the only record of the deviation. */ #define CAST_UINT32_PTR( ptr ) ( ( uint32_t * ) ( ptr ) ) #endif /* ifndef REDOSDEVIATIONS_H */