From 715336adfee1c3c99f26be1b34b6e3d3af9d51ca Mon Sep 17 00:00:00 2001 From: Yonggang Luo Date: Tue, 21 Oct 2025 15:53:14 +0800 Subject: [PATCH] aarch64: document the CNTFRQ_EL0 Signed-off-by: Yonggang Luo --- libcpu/aarch64/common/cpu_gcc.S | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/libcpu/aarch64/common/cpu_gcc.S b/libcpu/aarch64/common/cpu_gcc.S index ab15f4c241a..840668a78b6 100644 --- a/libcpu/aarch64/common/cpu_gcc.S +++ b/libcpu/aarch64/common/cpu_gcc.S @@ -119,7 +119,10 @@ rt_hw_get_cntpct_val: ret /* - *get gtimer frq value + * get gtimer frq value + * According to the document `Arm A-profile Architecture Registers: + * CNTFRQ_EL0, Counter-timer Frequency Register` + * Bits [63:32] are reserved, so only the lower 32 bits take effect. */ .globl rt_hw_get_gtimer_frq rt_hw_get_gtimer_frq: