# GrallocFuncs ## **Overview** **Related Modules:** [Display](Display.md) **Description:** Defines pointers to the memory driver functions. ## **Summary** ## Data Fields

Variable Name	Description
AllocMem )(GrallocBuffer *buffer)	int32_t(* Allocates memory based on the parameters passed by the GUI.
FreeMem )(GrallocBuffer *buffer)	void(* Releases memory.
Mmap )(GrallocBuffer *buffer)	void ( Maps memory with a specified physical address and size to memory without cache in the process's address space.
MmapCache )(GrallocBuffer *buffer)	void ( Maps memory with a specified physical address and size to memory with cache in the process's address space.
Unmap )(GrallocBuffer *buffer)	int32_t(* Unmaps memory, that is, removes any mappings in the process's address space.
FlushCache )(GrallocBuffer *buffer)	int32_t(* Flushes data from the cache to memory and invalidates the data in the cache.
FlushMCache )(GrallocBuffer *buffer)	int32_t(* Flushes data from the cache mapping to Mmap to memory and invalidates the data in the cache.

## **Details** ## **Field Documentation** ## AllocMem ``` int32_t(* GrallocFuncs::AllocMem) ([GrallocBuffer](GrallocBuffer.md) *buffer) ``` **Description:** Allocates memory based on the parameters passed by the GUI. **Parameters:**

Name	Description
hdl	Indicates the pointer to the handle of memory.
type	Indicates the type of memory to allocate. The value[/table/tgroup/tbody/row/entry/div {""}) [/table/tgroup/tbody/row/entry/div/div {""}) 0 (div] (div] indicates memory without cache, [/table/tgroup/tbody/row/entry/div {""}) [/table/tgroup/tbody/row/entry/div/div {""}) 1 (div] (div] indicates memory with cache, and[/table/tgroup/tbody/row/entry/div {""}) [/table/tgroup/tbody/row/entry/div/div {""}) 2 (div] (div] indicates shared memory.
size	Indicates the size of memory to allocate, in bytes.

**Returns:** Returns **0** if the operation is successful; returns an error code defined in [DispErrCode](Display.md#ga12a925dadef7573cd74d63d06824f9b0) otherwise. ## FlushCache ``` int32_t(* GrallocFuncs::FlushCache) ([GrallocBuffer](GrallocBuffer.md) *buffer) ``` **Description:** Flushes data from the cache to memory and invalidates the data in the cache. **Parameters:**

Name	Description
hdl	Indicates the pointer to the handle of the cache.
size	Indicates the size of the cache from which data is to flush.

**Returns:** Returns **0** if the operation is successful; returns an error code defined in [DispErrCode](Display.md#ga12a925dadef7573cd74d63d06824f9b0) otherwise. ## FlushMCache ``` int32_t(* GrallocFuncs::FlushMCache) ([GrallocBuffer](GrallocBuffer.md) *buffer) ``` **Description:** Flushes data from the cache mapping to [Mmap](GrallocFuncs.md#ab64438d785bc59050cd4f0a759bd531b) to memory and invalidates the data in the cache. **Parameters:**

Name	Description
hdl	Indicates the pointer to the handle of the cache.
size	Indicates the size of the cache from which data is to flush.

Name	Description
hdl	Indicates the pointer to the handle of memory that has been applied for.

## Mmap ``` void*(* GrallocFuncs::Mmap) ([GrallocBuffer](GrallocBuffer.md) *buffer) ``` **Description:** Maps memory with a specified physical address and size to memory without cache in the process's address space. **Parameters:**

Name	Description
phyAddr	Indicates the physical address of memory to map.
size	Indicates the size of memory to map.

**Returns:** Returns the pointer to a valid address if the operation is successful; returns **NULL** otherwise. ## MmapCache ``` void*(* GrallocFuncs::MmapCache) ([GrallocBuffer](GrallocBuffer.md) *buffer) ``` **Description:** Maps memory with a specified physical address and size to memory with cache in the process's address space. **Parameters:**

Name	Description
phyAddr	Indicates the physical address of memory to map.
size	Indicates the size of memory to map.

**Returns:** Returns the pointer to a valid address if the operation is successful; returns **NULL** otherwise. ## Unmap ``` int32_t(* GrallocFuncs::Unmap) ([GrallocBuffer](GrallocBuffer.md) *buffer) ``` **Description:** Unmaps memory, that is, removes any mappings in the process's address space. **Parameters:**

Name	Description
virAddr	Indicates the pointer to the virtual address of memory to unmap.
size	Indicates the size of memory to unmap.

**Returns:** Returns **0** if the operation is successful; returns an error code defined in [DispErrCode](Display.md#ga12a925dadef7573cd74d63d06824f9b0) otherwise.