From 2b80b92f028aa3726c6488eaaefddbdec43c5b54 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Tue, 12 Dec 2023 15:19:11 +0530 Subject: [PATCH] lib: sbi: Do not enter OpenSBI with mseccfg.MML == 1 On platforms with Smepmp, the previous booting stage must enter OpenSBI with mseccfg.MML == 0. This allows OpenSBI to configure it's own M-mode only regions without depending on the previous booting stage. Signed-off-by: Anup Patel --- lib/sbi/sbi_hart.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c index 46cd55d0..e2b93e6b 100644 --- a/lib/sbi/sbi_hart.c +++ b/lib/sbi/sbi_hart.c @@ -914,6 +914,16 @@ __pmp_skip: /* Mark hart feature detection done */ hfeatures->detected = true; + /* + * On platforms with Smepmp, the previous booting stage must + * enter OpenSBI with mseccfg.MML == 0. This allows OpenSBI + * to configure it's own M-mode only regions without depending + * on the previous booting stage. + */ + if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SMEPMP) && + (csr_read(CSR_MSECCFG) & MSECCFG_MML)) + return SBI_EILL; + return 0; }