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Diffstat (limited to 'Documentation/arm64/booting.rst')
| -rw-r--r-- | Documentation/arm64/booting.rst | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/arm64/booting.rst b/Documentation/arm64/booting.rst index a9192e7a231b..5822d6da9fa6 100644 --- a/Documentation/arm64/booting.rst +++ b/Documentation/arm64/booting.rst @@ -311,6 +311,28 @@ Before jumping into the kernel, the following conditions must be met: - ZCR_EL2.LEN must be initialised to the same value for all CPUs the kernel will execute on. + For CPUs with the Scalable Matrix Extension (FEAT_SME): + + - If EL3 is present: + + - CPTR_EL3.ESM (bit 12) must be initialised to 0b1. + + - SCR_EL3.EnTP2 (bit 41) must be initialised to 0b1. + + - SMCR_EL3.LEN must be initialised to the same value for all CPUs the + kernel will execute on. + + - If the kernel is entered at EL1 and EL2 is present: + + - CPTR_EL2.TSM (bit 12) must be initialised to 0b0. + + - CPTR_EL2.SMEN (bits 25:24) must be initialised to 0b11. + + - SCTLR_EL2.EnTP2 (bit 60) must be initialised to 0b1. + + - SMCR_EL2.LEN must be initialised to the same value for all CPUs the + kernel will execute on. + 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. Where the values documented |