[U-Boot] [PATCH 01/12] ARM: zynq: Enable the Neon instructions

Michal Simek michal.simek at xilinx.com
Wed Jan 14 10:17:51 CET 2015


From: Siva Durga Prasad Paladugu <siva.durga.paladugu at xilinx.com>

Added the lowlevel_init to enable the Neon instructions.

Initially the u-boot was causing undefined instruction
exception if loaded through tcl, and working fine if loaded
through FSBL. The exception was causing in convertion formula
of given time to ticks. It was because, the Neon instructions
were disabled and hence causing the undefined exception. In
FSBL case, the FSBL was enabling the Neon instructions. Hence,
added the lowlevel_init to enable the Neon instructions.

Signed-off-by: Siva Durga Prasad Paladugu <sivadur at xilinx.com>
Acked-by: Radhey Shyam Pandey <radheys at xilinx.com>
Signed-off-by: Michal Simek <michal.simek at xilinx.com>
---

 arch/arm/cpu/armv7/zynq/Makefile        |  1 +
 arch/arm/cpu/armv7/zynq/cpu.c           |  3 ---
 arch/arm/cpu/armv7/zynq/lowlevel_init.S | 26 ++++++++++++++++++++++++++
 3 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 arch/arm/cpu/armv7/zynq/lowlevel_init.S

diff --git a/arch/arm/cpu/armv7/zynq/Makefile b/arch/arm/cpu/armv7/zynq/Makefile
index 3363a3c71b98..901f2ce4cbb7 100644
--- a/arch/arm/cpu/armv7/zynq/Makefile
+++ b/arch/arm/cpu/armv7/zynq/Makefile
@@ -13,4 +13,5 @@ obj-y	+= cpu.o
 obj-y	+= ddrc.o
 obj-y	+= slcr.o
 obj-y	+= clk.o
+obj-y	+= lowlevel_init.o
 obj-$(CONFIG_SPL_BUILD)	+= spl.o
diff --git a/arch/arm/cpu/armv7/zynq/cpu.c b/arch/arm/cpu/armv7/zynq/cpu.c
index 816d0c5da7a5..d1bfec9f715e 100644
--- a/arch/arm/cpu/armv7/zynq/cpu.c
+++ b/arch/arm/cpu/armv7/zynq/cpu.c
@@ -10,9 +10,6 @@
 #include <asm/arch/sys_proto.h>
 #include <asm/arch/hardware.h>

-void lowlevel_init(void)
-{
-}

 #define ZYNQ_SILICON_VER_MASK	0xF0000000
 #define ZYNQ_SILICON_VER_SHIFT	28
diff --git a/arch/arm/cpu/armv7/zynq/lowlevel_init.S b/arch/arm/cpu/armv7/zynq/lowlevel_init.S
new file mode 100644
index 000000000000..6d714b711cbe
--- /dev/null
+++ b/arch/arm/cpu/armv7/zynq/lowlevel_init.S
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2013 Xilinx, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <asm-offsets.h>
+#include <config.h>
+#include <linux/linkage.h>
+
+ENTRY(lowlevel_init)
+
+	/* Enable the the VFP */
+	mrc	p15, 0, r1, c1, c0, 2
+	orr	r1, r1, #(0x3 << 20)
+	orr	r1, r1, #(0x3 << 20)
+	mcr	p15, 0, r1, c1, c0, 2
+	isb
+	fmrx	r1, FPEXC
+	orr	r1,r1, #(1<<30)
+	fmxr	FPEXC, r1
+
+	/* Move back to caller */
+	mov	pc, lr
+
+ENDPROC(lowlevel_init)
--
1.8.2.3

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