EDVIDSR, External Debug Virtual Context Sample Register

The EDVIDSR characteristics are:

Purpose

Contains sampled values captured on reading EDPCSR[31:0].

Configuration

EDVIDSR is in the Core power domain.

This register is present only when FEAT_PCSRv8 is implemented and FEAT_PCSRv8p2 is not implemented. Otherwise, direct accesses to EDVIDSR are RES0.

If FEAT_VHE is implemented, the format of this register differs depending on the value of EDSCR.SC2.

Implemented only if the OPTIONAL PC Sample-based Profiling Extension is implemented in the external debug registers space.

When the PC Sample-based Profiling Extension is implemented in the external debug registers space, if EL2 is not implemented and EL3 is not implemented, it is IMPLEMENTATION DEFINED whether EDVIDSR is implemented.

Note

FEAT_PCSRv8p2 implements the PC Sample-based Profiling Extension in the Performance Monitors registers space.

Attributes

EDVIDSR is a 32-bit register.

Field descriptions

When FEAT_VHE is not implemented or EDSCR.SC2 == 0:

313029282726252423222120191817161514131211109876543210
NSE2E3HVRES0VMID[15:8]VMID

This format applies in all Armv8.0 implementations.

NS, bit [31]

Non-secure state sample. Indicates the Security state associated with the most recent EDPCSR sample.

If EL3 is not implemented, this bit indicates the Effective value of SCR.NS.

NSMeaning
0b0

Sample is from Secure state.

0b1

Sample is from Non-secure state.

The reset behavior of this field is:

E2, bit [30]
When EL2 is implemented:

Exception level 2 status sample. Indicates whether the most recent EDPCSR sample was associated with EL2.

E2Meaning
0b0

Sample is not from EL2.

0b1

Sample is from EL2.

The reset behavior of this field is:


Otherwise:

Reserved, RES0.

E3, bit [29]
When EL3 is implemented and AArch64 is supported:

Exception level 3 status sample. Indicates whether the most recent EDPCSR sample was associated with EL3 using AArch64.

E3Meaning
0b0

Sample is not from EL3 using AArch64.

0b1

Sample is from EL3 using AArch64.

The reset behavior of this field is:


Otherwise:

Reserved, RES0.

HV, bit [28]

EDPCSRhi (EDPCSR[63:32]) valid. Indicates whether bits [63:32] of the most recent EDPCSR sample might be nonzero:

HVMeaning
0b0

Bits[63:32] of the most recent EDPCSR sample are zero.

0b1

Bits[63:32] of the most recent EDPCSR sample might be nonzero.

An EDVIDSR.HV value of 1 does not mean that the value of EDPCSRhi is nonzero. An EDVIDSR.HV value of 0 is a hint that EDPCSRhi (EDPCSR[63:32]) does not need to be read.

The reset behavior of this field is:

Bits [27:16]

Reserved, RES0.

VMID[15:8], bits [15:8]
When FEAT_VMID16 is implemented and EL2 is implemented:

Extension to VMID[7:0]. For more information, see VMID[7:0].

The reset behavior of this field is:


Otherwise:

Reserved, RES0.

VMID, bits [7:0]
When EL2 is implemented:

VMID sample. The VMID associated with the most recent EDPCSRlo (EDPCSR[31:0]) sample. When the most recent EDPCSR sample was generated:

The reset behavior of this field is:


Otherwise:

Reserved, RES0.

When (FEAT_VHE is implemented or FEAT_Debugv8p2 is implemented) and EDSCR.SC2 == 1:

313029282726252423222120191817161514131211109876543210
CONTEXTIDR_EL2

CONTEXTIDR_EL2, bits [31:0]

Context ID. The value of CONTEXTIDR_EL2 that is associated with the most recent EDPCSR sample. When the most recent EDPCSR sample is generated:

The reset behavior of this field is:

Accessing EDVIDSR

IMPLEMENTATION DEFINED extensions to external debug might make the value of this register UNKNOWN, see 'Permitted behavior that might make the PC Sample-based profiling registers UNKNOWN'.

EDVIDSR can be accessed through the external debug interface:

ComponentOffsetInstance
Debug0x0A8EDVIDSR

This interface is accessible as follows:


26/03/2024 09:49; 67c0ae5282a7629ba0ea0ba7267b43cd4f7939f6

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