image_decompress: add APIs for decompressing images

These APIs are used by platforms that need to decompress images.

image_decompress_init():
  This registers a temporary buffer and a decompressor callback.
  This should be called from platform init code.

image_decompress_prepare():
  This should be called before each compressed image is loaded.  The
  best location to call this will be bl*_plat_handle_pre_image_load().

image_decompress():
  This should be called after each compressed image is loaded.  The
  best location to call this will be bl*_plat_handle_post_image_load().

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

diff --git a/common/image_decompress.c b/common/image_decompress.c
new file mode 100644 (file)
index 0000000..7bd02b1
--- /dev/null
+++ b/common/image_decompress.c
@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch_helpers.h>
+#include <assert.h>
+#include <bl_common.h>
+#include <debug.h>
+#include <image_decompress.h>
+#include <stdint.h>
+
+static uintptr_t decompressor_buf_base;
+static uint32_t decompressor_buf_size;
+static decompressor_t *decompressor;
+static struct image_info saved_image_info;
+
+void image_decompress_init(uintptr_t buf_base, uint32_t buf_size,
+                          decompressor_t *_decompressor)
+{
+       decompressor_buf_base = buf_base;
+       decompressor_buf_size = buf_size;
+       decompressor = _decompressor;
+}
+
+void image_decompress_prepare(struct image_info *info)
+{
+       /*
+        * If the image is compressed, it should be loaded into the temporary
+        * buffer instead of its final destination.  We save image_info, then
+        * override ->image_base and ->image_max_size so that load_image() will
+        * transfer the compressed data to the temporary buffer.
+        */
+       saved_image_info = *info;
+       info->image_base = decompressor_buf_base;
+       info->image_max_size = decompressor_buf_size;
+}
+
+int image_decompress(struct image_info *info)
+{
+       uintptr_t compressed_image_base, image_base, work_base;
+       uint32_t compressed_image_size, work_size;
+       int ret;
+
+       /*
+        * The size of compressed data has been filled by load_image().
+        * Read it out before restoring image_info.
+        */
+       compressed_image_size = info->image_size;
+       compressed_image_base = info->image_base;
+       *info = saved_image_info;
+
+       assert(compressed_image_size <= decompressor_buf_size);
+
+       image_base = info->image_base;
+
+       /*
+        * Use the rest of the temporary buffer as workspace of the
+        * decompressor since the decompressor may need additional memory.
+        */
+       work_base = compressed_image_base + compressed_image_size;
+       work_size = decompressor_buf_size - compressed_image_size;
+
+       ret = decompressor(&compressed_image_base, compressed_image_size,
+                          &image_base, info->image_max_size,
+                          work_base, work_size);
+       if (ret) {
+               ERROR("Failed to decompress image (err=%d)\n", ret);
+               return ret;
+       }
+
+       /* image_base is updated to the final pos when decompressor() exits. */
+       info->image_size = image_base - info->image_base;
+
+       flush_dcache_range(info->image_base, info->image_size);
+
+       return 0;
+}

diff --git a/include/common/image_decompress.h b/include/common/image_decompress.h
new file mode 100644 (file)
index 0000000..aed8df3
--- /dev/null
+++ b/include/common/image_decompress.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __IMAGE_DECOMPRESS_H__
+#define __IMAGE_DECOMPRESS_H__
+
+#include <stddef.h>
+#include <stdint.h>
+
+struct image_info;
+
+typedef int (decompressor_t)(uintptr_t *in_buf, size_t in_len,
+                            uintptr_t *out_buf, size_t out_len,
+                            uintptr_t work_buf, size_t work_len);
+
+void image_decompress_init(uintptr_t buf_base, uint32_t buf_size,
+                          decompressor_t *decompressor);
+void image_decompress_prepare(struct image_info *info);
+int image_decompress(struct image_info *info);
+
+#endif /* __IMAGE_DECOMPRESS_H___ */