[PATCH 3/3] ARM: Fix exception table setup in MMU-less mode
Andrey Smirnov
andrew.smirnov at gmail.com
Sun Jan 10 16:58:12 PST 2016
Add code necessary for correct initialization of exception vector
table when MMU is disabled.
Note: Only ARMv7 support is implemented
Signed-off-by: Andrey Smirnov <andrew.smirnov at gmail.com>
---
Changes since v1 (http://lists.infradead.org/pipermail/barebox/2015-December/025685.html):
- Check CPU architecture at runtime
- Remove untested code for ARMv5
---
arch/arm/cpu/Makefile | 6 +++++
arch/arm/cpu/no-mmu.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 69 insertions(+)
create mode 100644 arch/arm/cpu/no-mmu.c
diff --git a/arch/arm/cpu/Makefile b/arch/arm/cpu/Makefile
index 418bcab..f708e8f 100644
--- a/arch/arm/cpu/Makefile
+++ b/arch/arm/cpu/Makefile
@@ -11,6 +11,12 @@ obj-$(CONFIG_CMD_ARM_MMUINFO) += mmuinfo.o
obj-$(CONFIG_OFDEVICE) += dtb.o
obj-$(CONFIG_MMU) += mmu.o cache.o mmu-early.o
pbl-$(CONFIG_MMU) += mmu-early.o
+
+ifeq ($(CONFIG_MMU),)
+obj-y += no-mmu.o
+pbl-y += no-mmu.o
+endif
+
obj-$(CONFIG_CPU_32v4T) += cache-armv4.o
pbl-$(CONFIG_CPU_32v4T) += cache-armv4.o
obj-$(CONFIG_CPU_32v5) += cache-armv5.o
diff --git a/arch/arm/cpu/no-mmu.c b/arch/arm/cpu/no-mmu.c
new file mode 100644
index 0000000..4da053f
--- /dev/null
+++ b/arch/arm/cpu/no-mmu.c
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2015 Zodiac Inflight Innovation
+ * Author: Andrey Smirnov <andrew.smirnov at gmail.com>
+ *
+ * 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.
+ *
+ */
+
+#define pr_fmt(fmt) "nommu: " fmt
+
+#include <common.h>
+#include <dma-dir.h>
+#include <init.h>
+#include <mmu.h>
+#include <errno.h>
+#include <linux/sizes.h>
+#include <asm/memory.h>
+#include <asm/barebox-arm.h>
+#include <asm/system.h>
+#include <asm/cache.h>
+#include <memory.h>
+#include <asm/system_info.h>
+#include <debug_ll.h>
+
+
+#define __exceptions_size (__exceptions_stop - __exceptions_start)
+
+static int nommu_v7_vectors_init(void)
+{
+ if (cpu_architecture() < CPU_ARCH_ARMv7)
+ return 0;
+
+
+ void *vectors;
+ u32 cr;
+
+
+ /*
+ * High vectors cannot be re-mapped, so we have to use normal
+ * vectors
+ */
+ cr = get_cr();
+ cr &= ~CR_V;
+ set_cr(cr);
+
+ arm_fixup_vectors();
+
+ vectors = xmemalign(PAGE_SIZE, PAGE_SIZE);
+ memset(vectors, 0, PAGE_SIZE);
+ memcpy(vectors, __exceptions_start, __exceptions_size);
+
+ set_vbar((unsigned int)vectors);
+
+ return 0;
+}
+mmu_initcall(nommu_v7_vectors_init);
--
2.5.0
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