[RFC PATCH 2/4] mt7622: add lowlevel_init from 2014-04

Frank Wunderlich linux at fw-web.de
Mon Aug 10 16:26:50 CEST 2020


From: Frank Wunderlich <frank-w at public-files.de>

add low level initialisation to gain access to jumparch64 target in
mt7622 ATF from 32bit uboot.

jumparch64 allows switching from 32bit to 64bit to
load 64bit kernel from 32bit uboot

Signed-off-by: Frank Wunderlich <frank-w at public-files.de>
---
 arch/arm/mach-mediatek/mt7622/Makefile        |  4 +++
 arch/arm/mach-mediatek/mt7622/lowlevel_init.S | 33 +++++++++++++++++++
 2 files changed, 37 insertions(+)
 create mode 100755 arch/arm/mach-mediatek/mt7622/lowlevel_init.S

diff --git a/arch/arm/mach-mediatek/mt7622/Makefile b/arch/arm/mach-mediatek/mt7622/Makefile
index 886ab7e4eb..5fe4505ddf 100644
--- a/arch/arm/mach-mediatek/mt7622/Makefile
+++ b/arch/arm/mach-mediatek/mt7622/Makefile
@@ -1,3 +1,7 @@
 # SPDX-License-Identifier:	GPL-2.0
 
 obj-y += init.o
+
+ifeq ($(CONFIG_ARCH_MEDIATEK_32),y)
+	obj-y += lowlevel_init.o
+endif
diff --git a/arch/arm/mach-mediatek/mt7622/lowlevel_init.S b/arch/arm/mach-mediatek/mt7622/lowlevel_init.S
new file mode 100755
index 0000000000..bf20cbd1e7
--- /dev/null
+++ b/arch/arm/mach-mediatek/mt7622/lowlevel_init.S
@@ -0,0 +1,33 @@
+/*
+ * (C) Copyright 2012 Stephen Warren
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+.globl lowlevel_init
+lowlevel_init:
+    /*Enable SMP bit*/
+	mrc	p15, 0, r0, c1, c0, 1
+	orr	r0, r0, #0x40
+	mcr	p15, 0, r0, c1, c0, 1
+	mov	pc, lr
+
+.global jumparch64_smc
+jumparch64_smc:
+	mov r3, r2
+	mov r2, r1
+	mov r1, r0
+	ldr r0, =0x82000200  /*please check MTK_SIP_KERNEL_TMP_AARCH32 in  vendor/arm/atf/include/bl31/services/sip_svc.h*/
+#	smc #0
+	.word   0xe1600070  @ SMC #0 to enter monitor - hand assembled
+	b   .
-- 
2.25.1



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