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Diffstat (limited to 'Documentation/arm64/booting.rst')
| -rw-r--r-- | Documentation/arm64/booting.rst | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/arm64/booting.rst b/Documentation/arm64/booting.rst index 5d78a6f5b0ae..a3f1a47b6f1c 100644 --- a/Documentation/arm64/booting.rst +++ b/Documentation/arm64/booting.rst @@ -248,6 +248,20 @@ Before jumping into the kernel, the following conditions must be met: - HCR_EL2.APK (bit 40) must be initialised to 0b1 - 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. + - 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. + The requirements described above for CPU mode, caches, MMUs, architected timers, coherency and system registers apply to all CPUs. All CPUs must enter the kernel in the same exception level. |