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GPTBR_EL3: Granule Protection Table Base Register

Purpose

The control register for Granule Protection Table base address.

Configuration

This register is present only when FEAT_RME is implemented. Otherwise, direct accesses to GPTBR_EL3 are UNDEFINED.

Attributes

GPTBR_EL3 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
RES0BADDR
BADDR

Bits [63:40]

Reserved, RES0.

BADDR, bits [39:0]

Base address for the level 0 GPT.

This field represents bits [51:12] of the level 0 GPT base address.

The level 0 GPT is aligned in memory to the greater of:

Bits [x:0] of the base address are treated as zero, where:

GPCCR_EL3.PPSpps
0b00032
0b00136
0b01040
0b01142
0b10044
0b10148
0b11052
GPCCR_EL3.L0GPTSZl0gptsz
0b000030
0b010034
0b011036
0b100139

If x is greater than 11, then BADDR[x - 12:0] are RES0.

The reset behavior of this field is:

Accessing GPTBR_EL3

Accesses to this register use the following encodings in the System register encoding space:

MRS <Xt>, GPTBR_EL3

op0op1CRnCRmop2
0b110b1100b00100b00010b100

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then UNDEFINED; elsif PSTATE.EL == EL2 then UNDEFINED; elsif PSTATE.EL == EL3 then X[t, 64] = GPTBR_EL3;

MSR GPTBR_EL3, <Xt>

op0op1CRnCRmop2
0b110b1100b00100b00010b100

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then UNDEFINED; elsif PSTATE.EL == EL2 then UNDEFINED; elsif PSTATE.EL == EL3 then if IsFeatureImplemented(FEAT_FGWTE3) && FGWTE3_EL3.GPTBR_EL3 == '1' then AArch64.SystemAccessTrap(EL3, 0x18); else GPTBR_EL3 = X[t, 64];