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#ifndef _mmu_405_h
#define _mmu_405_h
/*
Simple interface to the PowerPC 405 MMU
The intention here is just to allow the MMU to be used to define cacheability and
read/write/execute permissions in a simple enough way to fit entirely into the
64-entry TLB cache.
This code does not do address relocation and does not generate any MMU-related interrupts.
The process ID support is there for a possible future extension where RTEMS supports
setting the process ID on task switches, which allows per-process stack protection
This code will call fatal_error() if your add_space() calls overrun the 64 entries
Michael Hamel ADInstruments 2008
*/
#ifdef __cplusplus
extern "C" {
#endif
#include "stdint.h"
enum {
kAllProcessIDs = 0
};
typedef enum MMUAccessType {
executable,
readOnlyData,
readOnlyNoCache,
readWriteData,
readWriteNoCache,
readWriteExecutable
} MMUAccessType;
/* Initialise and clear the MMU */
void mmu_initialise(void);
/* Turn on/off data access translation */
bool mmu_enable_data(bool enable);
/* Turn on instruction translation */
bool mmu_enable_code(bool enable);
/* Define properties for an area of memory (must be 1K-aligned) */
void mmu_add_space(uint32_t startAddr, uint32_t endAddr, MMUAccessType permissions, uint8_t processID);
/* Delete a memory property definition */
void mmu_remove_space(uint32_t startAddr, uint32_t endAddr);
/* Return number of TLB entries out of total in use */
int mmu_get_tlb_count(void);
/* Allocate a new process ID and return it */
uint8_t mmu_new_processID(void);
/* Free a process ID that has been in use */
void mmu_free_processID(uint8_t freeThis);
/* Return the current process ID */
uint8_t mmu_current_processID(void);
/* Change the process ID to ID and return the old value */
uint8_t mmu_set_processID(uint8_t toID);
#ifdef __cplusplus
}
#endif
#endif //_mmu_405.h
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