MEMORY - MPU - Memory Protection Unit

MPU driver that allows the user to divide the memory space into different protection regions.

Data Structures
struct	mpu_entry_t

Macros
#define	CAST(to, from)

Enumerations
enum	eRegionSize {   MPU_REGION_SIZE_LOWLIMIT_FORBIDDEN = 10,   MPU_REGION_SIZE_4KB,   MPU_REGION_SIZE_8KB,   MPU_REGION_SIZE_16KB,   MPU_REGION_SIZE_32KB,   MPU_REGION_SIZE_64KB,   MPU_REGION_SIZE_128KB,   MPU_REGION_SIZE_256KB,   MPU_REGION_SIZE_512KB,   MPU_REGION_SIZE_1MB,   MPU_REGION_SIZE_2MB,   MPU_REGION_SIZE_4MB,   MPU_REGION_SIZE_8MB,   MPU_REGION_SIZE_16MB,   MPU_REGION_SIZE_32MB,   MPU_REGION_SIZE_64MB,   MPU_REGION_SIZE_128MB,   MPU_REGION_SIZE_256MB,   MPU_REGION_SIZE_512MB,   MPU_REGION_SIZE_1GB,   MPU_REGION_SIZE_2GB,   MPU_REGION_SIZE_4GB,   MPU_REGION_SIZE_HIGHLIMIT_FORBIDDEN }

Functions
void	disable_mpu (void)
	Disable the memory protection unit. MPU address checking is disabled, no exceptions will be generated by the MPU. More...
void	disable_mpu_entry (unsigned int region_number, unsigned int register_select)
void	enable_mpu (void)
	Enable the memory protection unit. MPU address checking is enabled. More...
bool	mpu_convert_kbsize_to_eregionsize (eRegionSize *peRegionSizeValue, U32 kBSizeValue)
	Converts an input region size expressed in kBytes to the corresponding eRegionSize type value. More...
void	select_subregion (unsigned int region_number, unsigned int pattern_select)
void	set_access_permissions (unsigned int region_number, unsigned int register_select, unsigned int right_access)
char	set_mpu_entry (const mpu_entry_t *mpu_entry, unsigned int region_number)
#define	MPU_APRA_ID   0
	MPU Access Permission Register A & B identifiers. More...
#define	MPU_APRB_ID   1
#define	MPU_PRIVR_UNPRIVNONE   AVR32_MPUAPRA_AP0_PRIV_R_UNPRIV_NONE
	MPU Access Permissions. More...
#define	MPU_PRIVRX_UNPRIVNONE   AVR32_MPUAPRA_AP0_PRIV_RX_UNPRIV_NONE
#define	MPU_PRIVRW_UNPRIVNONE   AVR32_MPUAPRA_AP0_PRIV_RW_UNPRIV_NONE
#define	MPU_PRIVRWX_UNPRIVNONE   AVR32_MPUAPRA_AP0_PRIV_RWX_UNPRIV_NONE
#define	MPU_PRIVR_UNPRIVR   AVR32_MPUAPRA_AP0_PRIV_R_UNPRIV_R
#define	MPU_PRIVRX_UNPRIVRX   AVR32_MPUAPRA_AP0_PRIV_RX_UNPRIV_RX
#define	MPU_PRIVRW_UNPRIVRW   AVR32_MPUAPRA_AP0_PRIV_RW_UNPRIV_RW
#define	MPU_PRIVRWX_UNPRIVRWX   AVR32_MPUAPRA_AP0_PRIV_RWX_UNPRIV_RWX
#define	MPU_PRIVRW_UNPRIVR   AVR32_MPUAPRA_AP0_PRIV_RW_UNPRIV_R
#define	MPU_PRIVRW_UNPRIVRX   AVR32_MPUAPRA_AP0_PRIV_RW_UNPRIV_RX
#define	MPU_PRIVNONE_UNPRIVNONE   AVR32_MPUAPRA_AP0_PRIV_NONE_UNPRIV_NONE
#define	MPU_SETUP_ENTRY_OK   0
	MPU entry set up function (set_mpu_entry) return codes. More...
#define	MPU_SETUP_ENTRY_INVALIDBASEADDR   1
#define	MPU_SETUP_ENTRY_INVALIDSIZE   2

#define CAST	(		to,
			from
	)

Value:

({                                     \
    typeof(from) __temp__ = from;        \
    to = *(typeof(to) *)&__temp__;       \
  })

#define MPU_APRA_ID   0

MPU Access Permission Register A & B identifiers.

Referenced by configure_memory_area().

#define MPU_APRB_ID   1

Referenced by configure_memory_area().

#define MPU_PRIVNONE_UNPRIVNONE   AVR32_MPUAPRA_AP0_PRIV_NONE_UNPRIV_NONE

#define MPU_PRIVR_UNPRIVNONE   AVR32_MPUAPRA_AP0_PRIV_R_UNPRIV_NONE

MPU Access Permissions.

Referenced by configure_memory_area().

#define MPU_PRIVR_UNPRIVR   AVR32_MPUAPRA_AP0_PRIV_R_UNPRIV_R

#define MPU_PRIVRW_UNPRIVNONE   AVR32_MPUAPRA_AP0_PRIV_RW_UNPRIV_NONE

Referenced by configure_memory_area().

#define MPU_PRIVRW_UNPRIVR   AVR32_MPUAPRA_AP0_PRIV_RW_UNPRIV_R

#define MPU_PRIVRW_UNPRIVRW   AVR32_MPUAPRA_AP0_PRIV_RW_UNPRIV_RW

#define MPU_PRIVRW_UNPRIVRX   AVR32_MPUAPRA_AP0_PRIV_RW_UNPRIV_RX

#define MPU_PRIVRWX_UNPRIVNONE   AVR32_MPUAPRA_AP0_PRIV_RWX_UNPRIV_NONE

#define MPU_PRIVRWX_UNPRIVRWX   AVR32_MPUAPRA_AP0_PRIV_RWX_UNPRIV_RWX

#define MPU_PRIVRX_UNPRIVNONE   AVR32_MPUAPRA_AP0_PRIV_RX_UNPRIV_NONE

#define MPU_PRIVRX_UNPRIVRX   AVR32_MPUAPRA_AP0_PRIV_RX_UNPRIV_RX

Referenced by configure_memory_area().

#define MPU_SETUP_ENTRY_INVALIDBASEADDR   1

Referenced by set_mpu_entry().

#define MPU_SETUP_ENTRY_INVALIDSIZE   2

Referenced by set_mpu_entry().

#define MPU_SETUP_ENTRY_OK   0

MPU entry set up function (set_mpu_entry) return codes.

Referenced by set_mpu_entry().

enum eRegionSize

Possible protected region sizes. Based on Table 5.1 in doc32002 "AVR32UC Technical Reference Manual Complete".

Enumerator
MPU_REGION_SIZE_LOWLIMIT_FORBIDDEN
MPU_REGION_SIZE_4KB
MPU_REGION_SIZE_8KB
MPU_REGION_SIZE_16KB
MPU_REGION_SIZE_32KB
MPU_REGION_SIZE_64KB
MPU_REGION_SIZE_128KB
MPU_REGION_SIZE_256KB
MPU_REGION_SIZE_512KB
MPU_REGION_SIZE_1MB
MPU_REGION_SIZE_2MB
MPU_REGION_SIZE_4MB
MPU_REGION_SIZE_8MB
MPU_REGION_SIZE_16MB
MPU_REGION_SIZE_32MB
MPU_REGION_SIZE_64MB
MPU_REGION_SIZE_128MB
MPU_REGION_SIZE_256MB
MPU_REGION_SIZE_512MB
MPU_REGION_SIZE_1GB
MPU_REGION_SIZE_2GB
MPU_REGION_SIZE_4GB
MPU_REGION_SIZE_HIGHLIMIT_FORBIDDEN

void disable_mpu

(

void

)

Disable the memory protection unit. MPU address checking is disabled, no exceptions will be generated by the MPU.

Control of the MPU control register MPUCR: disable MPUCR

References Set_system_register.

Referenced by handle_exception().

void disable_mpu_entry	(	unsigned int	region_number,
		unsigned int	register_select
	)

Disable a MPU entry

Parameters

region_number,:	MPU entry region number (0..7).
register_select,:	register A: '0' – B: '1'

References Set_system_register.

void enable_mpu

(

void

)

Enable the memory protection unit. MPU address checking is enabled.

Control of the MPU control register MPUCR: enable MPUCR

References Set_system_register.

Referenced by configure_memory_area().

bool mpu_convert_kbsize_to_eregionsize	(	eRegionSize *	peRegionSizeValue,
		U32	kBSizeValue
	)

Converts an input region size expressed in kBytes to the corresponding eRegionSize type value.

Parameters

kBSizeValue,:	input region size expressed in kBytes
peRegionSizeValue,:	output region size in the eRegionSize type

Returns

bool true if the conversion succeeded false if the conversion failed (the input is not a possible protected region size).

References clz, MPU_REGION_SIZE_HIGHLIMIT_FORBIDDEN, and MPU_REGION_SIZE_LOWLIMIT_FORBIDDEN.

Referenced by configure_memory_area().

void select_subregion	(	unsigned int	region_number,
		unsigned int	pattern_select
	)

Setup a Subregion

Parameters

region_number,:	MPU entry region number (0..7).
pattern_select,:	bit-field for the 16 subregions: register A: '0' – B: '1'

References Set_system_register.

Referenced by configure_memory_area().

void set_access_permissions	(	unsigned int	region_number,
		unsigned int	register_select,
		unsigned int	right_access
	)

Setup a register A and B

Parameters

region_number,:	MPU entry region number (0..7).
register_select,:	register A: '0' – B: '1'
right_access,:	R/W/X see doc32002.pdf (Table 5-3. Access permissions implied by the APn bits)

References Get_system_register, and Set_system_register.

Referenced by configure_memory_area().

char set_mpu_entry	(	const mpu_entry_t *	mpu_entry,
		unsigned int	region_number
	)

Setup a MPU entry

Parameters

mpu_entry,:	pointer to mpu_entry_t with the MPU settings (base address, size, validity, access permission) .
region_number,:	MPU entry region number (0..7).

Returns

int MPU_SETUP_ENTRY_OK if the setup succeeded MPU_SETUP_ENTRY_INVALIDBASEADDR if the setup failed because the input base address is not aligned to the size of the region. MPU_SETUP_ENTRY_INVALIDSIZE if the setup failed because the input size is not a power of 2 or is less than 4kB or is bigger than 4GB.

Setup a MPU entry

Parameters

mpu_entry,:	pointer to mpu_entry_t with the MPU settings (base address, size, validity).
region_number,:	MPU entry region number (0..7).

Returns

int MPU_SETUP_ENTRY_OK if the setup succeeded MPU_SETUP_ENTRY_INVALIDBASEADDR if the setup failed because the input base address is not aligned to the size of the region. MPU_SETUP_ENTRY_INVALIDSIZE if the setup failed because the input size is not one of the type eRegionSize.

References mpu_entry_t::addr, MPU_REGION_SIZE_HIGHLIMIT_FORBIDDEN, MPU_REGION_SIZE_LOWLIMIT_FORBIDDEN, MPU_SETUP_ENTRY_INVALIDBASEADDR, MPU_SETUP_ENTRY_INVALIDSIZE, MPU_SETUP_ENTRY_OK, Set_system_register, mpu_entry_t::size, Test_align, and mpu_entry_t::valid.

Referenced by configure_memory_area().