Debug
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
11-9
ID021414
Non-Confidential
Table 11-4
shows the DBGBCR
n
_EL1 bit assignments.
Table 11-4 DBGBCR
n
_EL1 bit assignments
Bits
Name
Function
[31:24]
-
Reserved,
RES
0.
[23:20]
BT
Breakpoint Type. This field controls the behavior of Breakpoint debug event generation. This includes the
meaning of the value held in the associated DBGBVR, indicating whether it is an instruction address match or
mismatch or a Context match. It also controls whether the breakpoint is linked to another breakpoint. The possible
values are:
0b0000
Unlinked instruction address match.
0b0001
Linked instruction address match.
0b0010
Unlinked ContextIDR match.
0b0011
Linked ContextIDR match.
0b0100
Unlinked instruction address mismatch.
0b0101
Linked instruction address mismatch.
0b1000
Unlinked VMID match.
0b1001
Linked VMID match.
0b1010
Unlinked VMID + CONTEXTIDR match.
0b1011
Linked VMID + CONTEXTIDR match.
All other values are reserved.
The field break down is:
•
BT[3:1]: Base type. If the breakpoint is not context-aware, these bits are
RES
0. Otherwise, the possible
values are:
0b000
Match address. DBGBVRn_EL1 is the address of an instruction.
0b001
Match context ID. DBGBVRn_EL1[31:0] is a context ID.
0b010
Address mismatch. Mismatch address. Behaves as type 0b000 if either:
•
In an AArch64 translation regime.
•
Halting debug-mode is enabled and halting is allowed.
Otherwise, DBGBVRn_EL1 is the address of an instruction to be stepped.
0b100
Match VMID. DBGBVRn_EL1[39:32] is a VMID.
0b101
Match VMID and context ID. DBGBVRn_EL1[31:0] is a context ID, and
DBGBVRn_EL1[39:32] is a VMID.
•
BT[0]: Enable linking.
[19:16]
LBN
Linked breakpoint number. For Linked address matching breakpoints, this specifies the index of the
Context-matching breakpoint linked to.
[15:14]
SSC
Security State Control. Determines the security states that a breakpoint debug event for breakpoint
n
is generated.
This field must be interpreted with the
Higher Mode Control
(HMC), and
Privileged Mode Control
(PMC), fields
to determine the mode and security states that can be tested.
See the
ARM
®
Architecture Reference Manual ARMv8, for ARMv8-A architecture profile
for possible values of
the fields.
[13]
HMC
Hyp Mode Control bit. Determines the debug perspective for deciding when a breakpoint debug event for
breakpoint
n
is generated.
This bit must be interpreted with the SSC and PMC fields to determine the mode and security states that can be
tested.
See the
ARM
®
Architecture Reference Manual ARMv8, for ARMv8-A architecture profile
for possible values of
the fields.
[12:9]
-
Reserved,
RES
0.