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-rw-r--r--Documentation/arm64/booting.rst39
1 files changed, 24 insertions, 15 deletions
diff --git a/Documentation/arm64/booting.rst b/Documentation/arm64/booting.rst
index a3f1a47b6f1c..7552dbc1cc54 100644
--- a/Documentation/arm64/booting.rst
+++ b/Documentation/arm64/booting.rst
@@ -173,7 +173,10 @@ Before jumping into the kernel, the following conditions must be met:
- Caches, MMUs
The MMU must be off.
- Instruction cache may be on or off.
+
+ The instruction cache may be on or off, and must not hold any stale
+ entries corresponding to the loaded kernel image.
+
The address range corresponding to the loaded kernel image must be
cleaned to the PoC. In the presence of a system cache or other
coherent masters with caches enabled, this will typically require
@@ -238,6 +241,7 @@ Before jumping into the kernel, the following conditions must be met:
- The DT or ACPI tables must describe a GICv2 interrupt controller.
For CPUs with pointer authentication functionality:
+
- If EL3 is present:
- SCR_EL3.APK (bit 16) must be initialised to 0b1
@@ -249,18 +253,22 @@ Before jumping into the kernel, the following conditions must be met:
- HCR_EL2.API (bit 41) must be initialised to 0b1
For CPUs with Activity Monitors Unit v1 (AMUv1) extension present:
+
- If EL3 is present:
- CPTR_EL3.TAM (bit 30) must be initialised to 0b0
- CPTR_EL2.TAM (bit 30) must be initialised to 0b0
- AMCNTENSET0_EL0 must be initialised to 0b1111
- AMCNTENSET1_EL0 must be initialised to a platform specific value
- having 0b1 set for the corresponding bit for each of the auxiliary
- counters present.
+
+ - CPTR_EL3.TAM (bit 30) must be initialised to 0b0
+ - CPTR_EL2.TAM (bit 30) must be initialised to 0b0
+ - AMCNTENSET0_EL0 must be initialised to 0b1111
+ - AMCNTENSET1_EL0 must be initialised to a platform specific value
+ having 0b1 set for the corresponding bit for each of the auxiliary
+ counters present.
+
- If the kernel is entered at EL1:
- AMCNTENSET0_EL0 must be initialised to 0b1111
- AMCNTENSET1_EL0 must be initialised to a platform specific value
- having 0b1 set for the corresponding bit for each of the auxiliary
- counters present.
+
+ - AMCNTENSET0_EL0 must be initialised to 0b1111
+ - AMCNTENSET1_EL0 must be initialised to a platform specific value
+ having 0b1 set for the corresponding bit for each of the auxiliary
+ counters present.
The requirements described above for CPU mode, caches, MMUs, architected
timers, coherency and system registers apply to all CPUs. All CPUs must
@@ -304,7 +312,8 @@ following manner:
Documentation/devicetree/bindings/arm/psci.yaml.
- Secondary CPU general-purpose register settings
- x0 = 0 (reserved for future use)
- x1 = 0 (reserved for future use)
- x2 = 0 (reserved for future use)
- x3 = 0 (reserved for future use)
+
+ - x0 = 0 (reserved for future use)
+ - x1 = 0 (reserved for future use)
+ - x2 = 0 (reserved for future use)
+ - x3 = 0 (reserved for future use)