From a7a617c18486f2946b2188f7cd106ae3542100ce Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=AE=8B=E8=B6=85?= <songchao@rt-thread.com>
Date: Fri, 25 Jun 2021 10:51:36 +0800
Subject: [PATCH] disable mmu after reset for uboot bring up

---
 libcpu/arm/cortex-a/start_gcc.S | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/libcpu/arm/cortex-a/start_gcc.S b/libcpu/arm/cortex-a/start_gcc.S
index 68a8099ea8..703b34a8ae 100644
--- a/libcpu/arm/cortex-a/start_gcc.S
+++ b/libcpu/arm/cortex-a/start_gcc.S
@@ -109,6 +109,19 @@ continue:
     msr cpsr_c, r0
 #endif
 
+    /* invalid tlb before enable mmu */
+    mrc p15, 0, r0, c1, c0, 0
+    bic r0, #1
+    mcr p15, 0, r0, c1, c0, 0
+    dsb
+    isb
+    mov r0, #0
+    mcr p15, 0, r0, c8, c7, 0
+    mcr p15, 0, r0, c7, c5, 0    /* iciallu */
+    mcr p15, 0, r0, c7, c5, 6    /* bpiall */
+    dsb
+    isb
+
 #ifdef RT_USING_USERSPACE
     ldr r5, =PV_OFFSET
 
-- 
Gitee