From 5d5e4e065f4e593c9e396a52b8e599cdc62c9e7d Mon Sep 17 00:00:00 2001
From: Robert Morris
Date: Thu, 25 Jul 2019 05:35:03 -0400
Subject: comments for timer setup

---
 kernel/kernelvec.S | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'kernel/kernelvec.S')

diff --git a/kernel/kernelvec.S b/kernel/kernelvec.S
index 0efde8b..9aabe96 100644
--- a/kernel/kernelvec.S
+++ b/kernel/kernelvec.S
@@ -86,6 +86,11 @@ kernelvec:
 .globl machinevec
 .align 4
 machinevec:
+        # start.c has set up the memory that mscratch points to:
+        # scratch[0,8,16] : register save area.
+        # scratch[32] : address of CLINT's MTIMECMP register.
+        # scratch[40] : desired interval between interrupts.
+        
         csrrw a0, mscratch, a0
         sd a1, 0(a0)
         sd a2, 8(a0)
-- 
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