The HRMR characteristics are:
If EL2 is the highest implemented Exception level and this register is implemented:
AArch32 System register HRMR bits [31:0] are architecturally mapped to AArch64 System register RMR_EL2[31:0] .
This register is present only when AArch32 is supported at any Exception level. Otherwise, direct accesses to HRMR are UNDEFINED.
Only implemented if EL2 is the highest implemented Exception level. In this case:
HRMR is a 32-bit register.
The HRMR 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 |
RES0 | RR | AA64 |
Reserved, RES0.
Reset Request. Setting this bit to 1 requests a Warm reset.
On a Warm reset, this field resets to 0.
When EL2 can use AArch64, determines which Execution state the PE boots into after a Warm reset:
AA64 | Meaning |
---|---|
0b0 |
AArch32. |
0b1 |
AArch64. |
On coming out of the Warm reset, execution starts at the IMPLEMENTATION DEFINED reset vector address of the specified Execution state.
If EL2 cannot use AArch64 this bit is RAZ/WI.
When implemented as a RW field, this field resets to 0 on a Cold reset.
Accesses to this register use the following encodings:
coproc | opc1 | CRn | CRm | opc2 |
---|---|---|---|---|
0b1111 | 0b100 | 0b1100 | 0b0000 | 0b010 |
if PSTATE.EL == EL1 && EL2Enabled() && IsHighestEL(EL2) && !ELUsingAArch32(EL2) && HSTR_EL2.T12 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif PSTATE.EL == EL1 && EL2Enabled() && IsHighestEL(EL2) && ELUsingAArch32(EL2) && HSTR.T12 == '1' then AArch32.TakeHypTrapException(0x03); elsif PSTATE.EL == EL2 && IsHighestEL(EL2) then return HRMR; else UNDEFINED;
coproc | opc1 | CRn | CRm | opc2 |
---|---|---|---|---|
0b1111 | 0b100 | 0b1100 | 0b0000 | 0b010 |
if PSTATE.EL == EL1 && EL2Enabled() && IsHighestEL(EL2) && !ELUsingAArch32(EL2) && HSTR_EL2.T12 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif PSTATE.EL == EL1 && EL2Enabled() && IsHighestEL(EL2) && ELUsingAArch32(EL2) && HSTR.T12 == '1' then AArch32.TakeHypTrapException(0x03); elsif PSTATE.EL == EL2 && IsHighestEL(EL2) then HRMR = R[t]; else UNDEFINED;
30/09/2020 15:06; ccead0cb9f089f9ceec50268e82aec9e71047211
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