/*
* COPYRIGHT (c) 2012 Chris Johns <chrisj@rtems.org>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
/**
* @file
*
* @ingroup rtems_rtl
*
* @brief RTEMS Run-Time Linker Allocator
*/
#if !defined (_RTEMS_RTL_ALLOCATOR_H_)
#define _RTEMS_RTL_ALLOCATOR_H_
#include <stdbool.h>
#include "rtl-indirect-ptr.h"
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**
* Define the types of allocation the loader requires.
*
* @note It is best to use the object tag for general memory allocation and to
* leave the tags with specific access properties to the module data
*/
enum rtems_rtl_alloc_tags_e {
RTEMS_RTL_ALLOC_OBJECT, /**< A generic memory object. */
RTEMS_RTL_ALLOC_SYMBOL, /**< Memory used for symbols. */
RTEMS_RTL_ALLOC_EXTERNAL, /**< Memory used for external symbols. */
RTEMS_RTL_ALLOC_READ, /**< The memory is read only. */
RTEMS_RTL_ALLOC_READ_WRITE, /**< The memory is read and write. */
RTEMS_RTL_ALLOC_READ_EXEC /**< The memory is read and executable. */
};
/**
* The allocator tag type.
*/
typedef enum rtems_rtl_alloc_tags_e rtems_rtl_alloc_tag_t;
/**
* The number of tags.
*/
#define RTEMS_RTL_ALLOC_TAGS ((size_t) (RTEMS_RTL_ALLOC_READ_EXEC + 1))
/**
* Allocator handler handles all RTL allocations. It can be hooked and
* overridded for customised allocation schemes or memory maps.
*
* @param allocation If true the request is to allocate memory else free.
* @param tag The type of allocation request.
* @param address Pointer to the memory address. If an allocation the value is
* unspecific on entry and the allocated address or NULL on
* exit. The NULL value means the allocation failed. If a delete
* or free request the memory address is the block to free. A
* free request of NULL is silently ignored.
* @param size The size of the allocation if an allocation request and
* not used if deleting or freeing a previous allocation.
*/
typedef void (*rtems_rtl_allocator_t)(bool allocate,
rtems_rtl_alloc_tag_t tag,
void** address,
size_t size);
/**
* The allocator data.
*/
struct rtems_rtl_alloc_data_s {
/**< The memory allocator handler. */
rtems_rtl_allocator_t allocator;
/**< The indirect pointer chains. */
rtems_chain_control indirects[RTEMS_RTL_ALLOC_TAGS];
};
typedef struct rtems_rtl_alloc_data_s rtems_rtl_alloc_data_t;
/**
* Initialise the allocate data.
*
* @param data The data to initialise.
*/
void rtems_rtl_alloc_initialise (rtems_rtl_alloc_data_t* data);
/**
* The Runtime Loader allocator new allocates new memory and optionally clear
* the memory if requested.
*
* @param tag The type of allocation request.
* @param size The size of the allocation.
* @param zero If true the memory is cleared.
* @return void* The memory address or NULL is not memory available.
*/
void* rtems_rtl_alloc_new (rtems_rtl_alloc_tag_t tag, size_t size, bool zero);
/**
* The Runtime Loader allocator delete deletes allocated memory.
*
* @param tag The type of allocation request.
* @param address The memory address to delete. A NULL is ignored.
*/
void rtems_rtl_alloc_del (rtems_rtl_alloc_tag_t tag, void* address);
/**
* Hook the Runtime Loader allocatior. A handler can call the previous handler
* in the chain to use it for specific tags. The default handler uses the
* system heap. Do not unhook your handler if memory it allocates has not been
* returned.
*
* @param handler The handler to use as the allocator.
* @return rtems_rtl_alloc_handler_t The previous handler.
*/
rtems_rtl_allocator_t rtems_rtl_alloc_hook (rtems_rtl_allocator_t handler);
/**
* Allocate memory to an indirect handle.
*
* @param tag The type of allocation request.
* @param handle The handle to allocate the memory to.
* @param size The size of the allocation.
*/
void rtems_rtl_alloc_indirect_new (rtems_rtl_alloc_tag_t tag,
rtems_rtl_ptr_t* handle,
size_t size);
/**
* Free memory from an indirect handle.
*
* @param tag The type of allocation request.
* @param handle The handle to free the memory from.
*/
void rtems_rtl_alloc_indirect_del (rtems_rtl_alloc_tag_t tag,
rtems_rtl_ptr_t* handle);
/**
* Allocate the memory for a module given the size of the text, const, data and
* bss sections. If any part of the allocation fails the no memory is
* allocated.
*
* @param text_base Pointer to the text base pointer.
* @param text_size The size of the read/exec section.
* @param const_base Pointer to the const base pointer.
* @param const_size The size of the read only section.
* @param eh_base Pointer to the eh base pointer.
* @param eh_size The size of the eh section.
* @param data_base Pointer to the data base pointer.
* @param data_size The size of the read/write secton.
* @param bss_base Pointer to the bss base pointer.
* @param bss_size The size of the read/write.
* @retval true The memory has been allocated.
* @retval false The allocation of memory has failed.
*/
bool rtems_rtl_alloc_module_new (void** text_base, size_t text_size,
void** const_base, size_t const_size,
void** eh_base, size_t eh_size,
void** data_base, size_t data_size,
void** bss_base, size_t bss_size);
/**
* Free the memory allocated to a module.
*
* @param text_base Pointer to the text base pointer.
* @param const_base Pointer to the const base pointer.
* @param eh_base Pointer to the eh base pointer.
* @param data_base Pointer to the data base pointer.
* @param bss_base Pointer to the bss base pointer.
*/
void rtems_rtl_alloc_module_del (void** text_base, void** const_base,
void** eh_base, void** data_base,
void** bss_base);
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif
