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[lib] add MMU init/reset function

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stnolting 2024-02-04 02:00:25 +01:00
parent c52cf9a602
commit d6070d884d
2 changed files with 21 additions and 2 deletions
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1
sw/lib/include/neorv32_cpu_mmu.h
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@ -68,6 +68,7 @@
**************************************************************************/
/**@{*/
int neorv32_cpu_mmu_available(void);
void neorv32_cpu_mmu_init(void);
void neorv32_cpu_mmu_atp_enable(void);
void neorv32_cpu_mmu_atp_disable(void);
int neorv32_cpu_mmu_tlb_size(void);

22
sw/lib/source/neorv32_cpu_mmu.c
View file

@ -59,6 +59,24 @@ int neorv32_cpu_mmu_available(void) {
}
/**********************************************************************//**
* Initialize (reset) MMU.
*
* @warning This function has to be called before enabling the MMU.
**************************************************************************/
void neorv32_cpu_mmu_init(void) {
int num_pte = neorv32_cpu_mmu_tlb_size();
// set all entires to all-zero
int index;
for (index=0; index<num_pte; index++) {
neorv32_cpu_mmu_pte_configure(0, (uint32_t)index, 0, 0); // instruction TLB entry
neorv32_cpu_mmu_pte_configure(1, (uint32_t)index, 0, 0); // data TLB entry
}
}
/**********************************************************************//**
* Enable MMU address translation and protection.
**************************************************************************/
@ -111,7 +129,7 @@ int neorv32_cpu_mmu_pte_configure(int id_sel, uint32_t vpn, uint32_t ppn, uint8_
// select indexed TLB entry
uint32_t sel = index;
sel |= (uint32_t)(id_sel) << 31;
sel |= (uint32_t)(id_sel) << 31; // instruction / data TLB
neorv32_cpu_csr_write(CSR_MXMMUSEL, sel);
// align
@ -119,7 +137,7 @@ int neorv32_cpu_mmu_pte_configure(int id_sel, uint32_t vpn, uint32_t ppn, uint8_
uint32_t p = ppn << 10;
uint32_t f = (uint32_t)(att);
// update entry
// write PTE
neorv32_cpu_csr_write(CSR_MXMMUVPN, v);
neorv32_cpu_csr_write(CSR_MXMMUPTE, p | f);