From: Gabe Black <gabebl...@chromium.org>
The default implementation of this function is just memset, but other
implementations will be needed when physical memory isn't accessible by
U-Boot using normal addressing mechanisms.
Signed-off-by: Gabe Black <gabebl...@chromium.org>
Signed-off-by: Che-Liang Chiou <clch...@chromium.org>
Signed-off-by: Simon Glass <s...@chromium.org>
---
Changes in v2:
- Update README and add to Makefile
README | 8 ++++++++
include/physmem.h | 21 +++++++++++++++++++++
lib/Makefile | 1 +
lib/physmem.c | 24 ++++++++++++++++++++++++
4 files changed, 54 insertions(+), 0 deletions(-)
create mode 100644 include/physmem.h
create mode 100644 lib/physmem.c
diff --git a/README b/README
index ed7d270..c7aab18 100644
--- a/README
+++ b/README
@@ -2200,6 +2200,14 @@ CBFS (Coreboot Filesystem) support
HERMES, IP860, RPXlite, LWMON,
FLAGADM, TQM8260
+- Access to physical memory region (> 4GB)
+ Some basic support is provided for operations on memory not
+ normally accessible to U-Boot - e.g. some architectures
+ support access to more than 4GB of memory on 32-bit
+ machines using physical address extension or similar.
+ Define CONFIG_PHYSMEM to access this basic support, which
+ currently only supports clearing the memory.
+
- Error Recovery:
CONFIG_PANIC_HANG
diff --git a/include/physmem.h b/include/physmem.h
new file mode 100644
index 0000000..03d3a78
--- /dev/null
+++ b/include/physmem.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ */
+
+/*
+ * These functions work like memset but operate on physical memory which may
+ * not be accessible directly.
+ *
+ * @param s The physical address to start setting memory at.
+ * @param c The character to set each byte of the region to.
+ * @param n The number of bytes to set.
+ *
+ * @return The physical address of the memory which was set.
+ */
+phys_addr_t arch_phys_memset(phys_addr_t s, int c, phys_size_t n);
diff --git a/lib/Makefile b/lib/Makefile
index e44e045..f83f6e8 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -48,6 +48,7 @@ COBJS-$(CONFIG_LMB) += lmb.o
COBJS-y += ldiv.o
COBJS-$(CONFIG_MD5) += md5.o
COBJS-y += net_utils.o
+COBJS-$(CONFIG_PHYSMEM) += physmem.o
COBJS-y += qsort.o
COBJS-$(CONFIG_SHA1) += sha1.o
COBJS-$(CONFIG_SHA256) += sha256.o
diff --git a/lib/physmem.c b/lib/physmem.c
new file mode 100644
index 0000000..0f035ed
--- /dev/null
+++ b/lib/physmem.c
@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ */
+
+#include <common.h>
+#include <physmem.h>
+
+static phys_addr_t __arch_phys_memset(phys_addr_t s, int c, phys_size_t n)
+{
+ void *s_ptr = (void *)(uintptr_t)s;
+
+ assert(((phys_addr_t)(uintptr_t)s) == s);
+ assert(((phys_addr_t)(uintptr_t)(s + n)) == s + n);
+ return (phys_addr_t)(uintptr_t)memset(s_ptr, c, n);
+}
+
+phys_addr_t arch_phys_memset(phys_addr_t s, int c, phys_size_t n)
+ __attribute__((weak, alias("__arch_phys_memset")));
--
1.7.7.3
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