SDER32_EL2, AArch32 Secure Debug Enable Register

The SDER32_EL2 characteristics are:

Purpose

Allows access to the AArch32 register SDER from Secure EL2 and EL3 only.

Configuration

This register is present only when ARMv8.4-SecEL2 is implemented and EL1 supports AArch32. Otherwise, direct accesses to SDER32_EL2 are UNDEFINED.

This register is ignored by the PE when when one or more of the following are true:

RW fields in this register reset to architecturally UNKNOWN values.

Attributes

SDER32_EL2 is a 64-bit register.

Field descriptions

The SDER32_EL2 bit assignments are:

6362616059585756555453525150494847464544434241403938373635343332
RES0
RES0SUNIDENSUIDEN
313029282726252423222120191817161514131211109876543210

Bits [63:2]

Reserved, RES0.

SUNIDEN, bit [1]

Secure User Non-Invasive Debug Enable.

SUNIDENMeaning
0b0

This bit does not affect Performance Monitors event counting at Secure EL0.

0b1

If EL1 is using AArch32, Performance Monitors event counting is allowed in Secure EL0.

On a Warm reset, this field resets to an architecturally UNKNOWN value.

SUIDEN, bit [0]

Secure User Invasive Debug Enable.

SUIDENMeaning
0b0

This bit does not affect the generation of debug exceptions at Secure EL0.

0b1

If EL1 is using AArch32, debug exceptions from Secure EL0 are enabled.

On a Warm reset, this field resets to an architecturally UNKNOWN value.

Accessing the SDER32_EL2

Accesses to this register use the following encodings:

MRS <Xt>, SDER32_EL2

op0op1CRnCRmop2
0b110b1000b00010b00110b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && HCR_EL2.NV == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else return SDER32_EL2; elsif PSTATE.EL == EL3 then return SDER32_EL2;

MSR SDER32_EL2, <Xt>

op0op1CRnCRmop2
0b110b1000b00010b00110b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && HCR_EL2.NV == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else UNDEFINED; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else SDER32_EL2 = X[t]; elsif PSTATE.EL == EL3 then SDER32_EL2 = X[t];




27/09/2019 18:48; 6134483bd14dc8c12a99c984cbfe3431cc1c9707

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