The DACR characteristics are:
Defines the access permission for each of the sixteen memory domains.
AArch32 System register DACR bits [31:0] are architecturally mapped to AArch64 System register DACR32_EL2[31:0] .
This register is present only when AArch32 is supported at any Exception level. Otherwise, direct accesses to DACR are UNDEFINED.
This register has no function when TTBCR.EAE is set to 1, to select the Long-descriptor translation table format.
DACR is a 32-bit register.
The DACR bit assignments are:
31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
D15 | D14 | D13 | D12 | D11 | D10 | D9 | D8 | D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 |
Domain n access permission, where n = 0 to 15. Permitted values are:
D<n> | Meaning |
---|---|
0b00 |
No access. Any access to the domain generates a Domain fault. |
0b01 |
Client. Accesses are checked against the permission bits in the translation tables. |
0b11 |
Manager. Accesses are not checked against the permission bits in the translation tables. |
The value 0b10 is reserved.
This field resets to an architecturally UNKNOWN value.
Accesses to this register use the following encodings:
coproc | opc1 | CRn | CRm | opc2 |
---|---|---|---|---|
0b1111 | 0b000 | 0b0011 | 0b0000 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T3 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T3 == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TRVM == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.TRVM == '1' then AArch32.TakeHypTrapException(0x03); elsif HaveEL(EL3) && ELUsingAArch32(EL3) then return DACR_NS; else return DACR; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && ELUsingAArch32(EL3) then return DACR_NS; else return DACR; elsif PSTATE.EL == EL3 then if SCR.NS == '0' then return DACR_S; else return DACR_NS;
coproc | opc1 | CRn | CRm | opc2 |
---|---|---|---|---|
0b1111 | 0b000 | 0b0011 | 0b0000 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T3 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T3 == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.TVM == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.TVM == '1' then AArch32.TakeHypTrapException(0x03); elsif HaveEL(EL3) && ELUsingAArch32(EL3) then DACR_NS = R[t]; else DACR = R[t]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && ELUsingAArch32(EL3) then DACR_NS = R[t]; else DACR = R[t]; elsif PSTATE.EL == EL3 then if SCR.NS == '0' && CP15SDISABLE == HIGH then UNDEFINED; elsif SCR.NS == '0' && CP15SDISABLE2 == HIGH then UNDEFINED; else if SCR.NS == '0' then DACR_S = R[t]; else DACR_NS = R[t];
01/07/2020 15:57; 80324f0b9997bede489cc15ad1565345720bcd2a
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