ARM VMSA (Virtual Memory System Architecture) §
VMSA Address Types & Spaces §
VA §
- Maximum address width: 48bits
- Address Space Size: 256TB
| VA range count | range | subrange |
|---|
| Translation stage with single VA Range | 0x0000 0000 0000 0000 ~ 0x0000 FFFF FFFF FFFF | x |
| Translation stage with two VA Range | 0x0000 0000 0000 0000 ~ 0x0000 FFFF FFFF FFFF | 0x FFFF 0000 0000 0000 ~ 0xFFFF FFFF FFFF FFFF |
(Special Case) ARMv8.2-LVA Implemented & 64KB translation granule §
- Maximum address width: 52bits
- Address Space Size: 4PB
| VA range count | range | subrange |
|---|
| Translation stage with single VA Range | 0x0000 0000 0000 0000 ~ 0x000F FFFF FFFF FFFF | x |
| Translation stage with two VA Range | 0x0000 0000 0000 0000 ~ 0x000F FFFF FFFF FFFF | 0xFFF0 0000 0000 0000 ~ 0xFFFF FFFF FFFF FFFF |
Translation stage with single VA Range §
Translation stage with two VA Ranges §
| OA | Granule | 63 to 59 | 58 to 51 | 50 | 49 to 48 | 47 to 16 | 15 to 14 | 13 to 12 | 11 to 10 | 9 to 8 | 7 to 2 | 1 | 0 |
|---|
| 52bit | 4KB | Attributes | IGNORED | RES0 | Next-level Table Address[49:12] | < | < | < | IGNORED | Next-level Table Address[51:50] | IGNORED | 1 | 1 |
| 52bit | 16KB | Attributes | IGNORED | RES0 | Next-level Table Address[49:14] | < | < | RES0 | IGNORED | Next-level Table Address[51:50] | IGNORED | 1 | 1 |
| 52bit | 64KB | Attributes | IGNORED | RES0 | < | Next-level Table Address[47:16] | Next-level Table Address[51:48] | < | < | < | < | 1 | 1 |
| 48bit | 4KB | Attributes | IGNORED | RES0 | < | Next-level Table Address[47:12] | < | < | IGNORED | < | < | 1 | 1 |
| 48bit | 16KB | Attributes | IGNORED | RES0 | < | Next-level Table Address[47:14] | < | RES0 | IGNORED | < | < | 1 | 1 |
| 48bit | 64KB | Attributes | IGNORED | RES0 | < | Next-level Table Address[47:16] | RES0 | < | IGNORED | < | < | 1 | 1 |
Attribute Field §
| Condition | 63 | 62~61 | 60 | 59 | 58~53 | 52 | 51 |
|---|
| Stage 1 | NSTable | APTable | UXNTable or XNTable | PXNTable or RES0 or IGNORED | IGNORED | Protected or IGNORED | IGNORED |
| Stage 2 with indirect permission disabled | RES0 | RES0 | < | < | IGNORED | < | < |
| Stage 2 with indirect permission enabled | RES0 | IGNORED | < | < | IGNORED | < | < |
VMSAv8-64 Page Descriptor format §