From: "Richard W.M. Jones" <rjones@redhat.com>

Date: Tue, 19 Aug 2014 18:56:28 +0100

Subject: [PATCH] loader: Add load_image_gzipped function.

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As the name suggests this lets you load a ROM/disk image that is

gzipped.  It is uncompressed before storing it in guest memory.

Signed-off-by: Richard W.M. Jones <rjones@redhat.com>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

Message-id: 1407831259-2115-2-git-send-email-rjones@redhat.com

[PMM: removed stray space before ')']

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

(cherry picked from commit 235e74afcb85285a8e35e75f0cb6e6811267bb75)

---

 hw/core/loader.c    | 48 ++++++++++++++++++++++++++++++++++++++++++++++++

 include/hw/loader.h |  1 +

 2 files changed, 49 insertions(+)

diff --git a/hw/core/loader.c b/hw/core/loader.c

index 2bf6b8f..0fde699 100644

--- a/hw/core/loader.c

+++ b/hw/core/loader.c

@@ -577,6 +577,54 @@ int load_ramdisk(const char *filename, hwaddr addr, uint64_t max_sz)

     return load_uboot_image(filename, NULL, &addr, NULL, IH_TYPE_RAMDISK);

 }

+/* This simply prevents g_malloc in the function below from allocating

+ * a huge amount of memory, by placing a limit on the maximum

+ * uncompressed image size that load_image_gzipped will read.

+ */

+#define LOAD_IMAGE_MAX_GUNZIP_BYTES (256 << 20)

+

+/* Load a gzip-compressed kernel. */

+int load_image_gzipped(const char *filename, hwaddr addr, uint64_t max_sz)

+{

+    uint8_t *compressed_data = NULL;

+    uint8_t *data = NULL;

+    gsize len;

+    ssize_t bytes;

+    int ret = -1;

+

+    if (!g_file_get_contents(filename, (char **) &compressed_data, &len,

+                             NULL)) {

+        goto out;

+    }

+

+    /* Is it a gzip-compressed file? */

+    if (len < 2 ||

+        compressed_data[0] != 0x1f ||

+        compressed_data[1] != 0x8b) {

+        goto out;

+    }

+

+    if (max_sz > LOAD_IMAGE_MAX_GUNZIP_BYTES) {

+        max_sz = LOAD_IMAGE_MAX_GUNZIP_BYTES;

+    }

+

+    data = g_malloc(max_sz);

+    bytes = gunzip(data, max_sz, compressed_data, len);

+    if (bytes < 0) {

+        fprintf(stderr, "%s: unable to decompress gzipped kernel file\n",

+                filename);

+        goto out;

+    }

+

+    rom_add_blob_fixed(filename, data, bytes, addr);

+    ret = bytes;

+

+ out:

+    g_free(compressed_data);

+    g_free(data);

+    return ret;

+}

+

 /*

  * Functions for reboot-persistent memory regions.

  *  - used for vga bios and option roms.

diff --git a/include/hw/loader.h b/include/hw/loader.h

index 796cbf9..00c9117 100644

--- a/include/hw/loader.h

+++ b/include/hw/loader.h

@@ -15,6 +15,7 @@ int get_image_size(const char *filename);

 int load_image(const char *filename, uint8_t *addr); /* deprecated */

 int load_image_targphys(const char *filename, hwaddr,

                         uint64_t max_sz);

+int load_image_gzipped(const char *filename, hwaddr addr, uint64_t max_sz);

 #define ELF_LOAD_FAILED       -1

 #define ELF_LOAD_NOT_ELF      -2