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authorAnup Patel <anup.patel@wdc.com>2020-11-21 08:58:39 +0300
committerAnup Patel <anup@brainfault.org>2020-12-04 15:26:10 +0300
commit8d2edc4fc957588e23d09c8f567a94cd737405d3 (patch)
tree8a3d3600d83002c98eebd8334789e88c624d29f4
parent2677324f906133db8596de4868df87cb1224f113 (diff)
downloadopensbi-8d2edc4fc957588e23d09c8f567a94cd737405d3.tar.xz
lib: sbi: Fix sbi_hart_switch_mode() for u-mode
We should check and access N-extension CSRs in sbi_hart_switch_mode() when next_mode is u-mode because N-extension is optional. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
-rw-r--r--lib/sbi/sbi_hart.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
index 30d8aef..fc86e9f 100644
--- a/lib/sbi/sbi_hart.c
+++ b/lib/sbi/sbi_hart.c
@@ -522,9 +522,11 @@ sbi_hart_switch_mode(unsigned long arg0, unsigned long arg1,
csr_write(CSR_SIE, 0);
csr_write(CSR_SATP, 0);
} else if (next_mode == PRV_U) {
- csr_write(CSR_UTVEC, next_addr);
- csr_write(CSR_USCRATCH, 0);
- csr_write(CSR_UIE, 0);
+ if (misa_extension('N')) {
+ csr_write(CSR_UTVEC, next_addr);
+ csr_write(CSR_USCRATCH, 0);
+ csr_write(CSR_UIE, 0);
+ }
}
register unsigned long a0 asm("a0") = arg0;