diff options
| author | Christian Cunningham <cc@localhost> | 2022-02-24 23:38:38 -0700 |
|---|---|---|
| committer | Christian Cunningham <cc@localhost> | 2022-02-24 23:38:38 -0700 |
| commit | 9169796632fcdeb5e8e74ed60c6cbe31081e51f2 (patch) | |
| tree | f9076beb2cbdd4f8cb2677b9be64fa145b0fc3d1 /src/lib/mmu.S | |
| parent | a9e89946ad7f6918b954d7416c755a90c0eace9d (diff) | |
MMU and working on hardware
Diffstat (limited to 'src/lib/mmu.S')
| -rw-r--r-- | src/lib/mmu.S | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/src/lib/mmu.S b/src/lib/mmu.S new file mode 100644 index 0000000..faca3cc --- /dev/null +++ b/src/lib/mmu.S @@ -0,0 +1,45 @@ +.section .text +.globl mmu_start +mmu_start: + mov r2, #0 + // Invalidate Caches + mcr p15,0,r2,c7,c1,6 + // Invalidate TLB entries + mcr p15,0,r2,c8,c7,0 + // Data synchronisation barrier + mcr p15,0,r2,c7,c10,4 + + // Set all domains to 0b11 + mvn r2, #0 + bic r2, #0xC + mcr p15,0,r2,c3,c0,0 + + // Set the translation table base address (remember to align 16 KiB!) + mcr p15,0,r0,c2,c0,0 + mcr p15,0,r0,c2,c0,1 + mov r3, #0 + mcr p15,0,r3,c2,c0,2 + + // Set the bits mentioned above + mrc p15,0,r2,c1,c0,0 + orr r2,r2,r1 + mcr p15,0,r2,c1,c0,0 + bx lr + +.globl mmu_stop +mmu_stop: + mrc p15,0,r2,c1,c0,0 + bic r2,#0x1000 + bic r2,#0x0004 + bic r2,#0x0001 + mcr p15,0,r2,c1,c0,0 + bx lr + +.globl tlb_invalidate +tlb_invalidate: + mov r2, #0 + // Invalidate Entries + mcr p15, 0, r2, c8, c7, 0 + // DSB + mcr p15, 0, r2, c7, c10, 4 + bx lr |