[Qemu-devel] [PATCH v3 1/2] hw/loader: Support ramdisk with u-boot header

[Soren Brinkmann <soren.brinkmann@xilinx.com>]

Introduce 'load_ramdisk()' which can load "normal" ramdisks and ramdisks
with a u-boot header.
To enable this and leverage synergies 'load_uimage()' is refactored to
accomodate this additional use case.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
---
v3:
 - remove fallback code from load_ramdisk(). This way the function
   loads a u-boot-wrapped ramdisk or returns an error, the arch specific
   loader code is supposed to handle.
   Changed this way to achieve symmetry with the kernel loading code.

v2:
 - document the new 'load_ramdisk()' function
 - print the image type byte in the error messages for unsupported
   u-boot images
 - load_uimage() and load_ramdisk() both use load_uboot_image() to load
   images. Let the callers pass the expected image type to
   load_uboot_image to allow error checking for wrong image types. E.g.
   passing a ramdisk image to the load_uimage routine.


 hw/core/loader.c    | 84 +++++++++++++++++++++++++++++++++++++----------------
 include/hw/loader.h | 13 +++++++++
 2 files changed, 72 insertions(+), 25 deletions(-)

diff --git a/hw/core/loader.c b/hw/core/loader.c
index 44311ff..c3c28cf 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -434,15 +434,17 @@ static ssize_t gunzip(void *dst, size_t dstlen, uint8_t *src,
 }
 
 /* Load a U-Boot image.  */
-int load_uimage(const char *filename, hwaddr *ep,
-                hwaddr *loadaddr, int *is_linux)
+static int load_uboot_image(const char *filename, hwaddr *ep, hwaddr *loadaddr,
+                            int *is_linux, uint8_t image_type)
 {
     int fd;
     int size;
+    hwaddr address;
     uboot_image_header_t h;
     uboot_image_header_t *hdr = &h;
     uint8_t *data = NULL;
     int ret = -1;
+    int do_uncompress = 0;
 
     fd = open(filename, O_RDONLY | O_BINARY);
     if (fd < 0)
@@ -457,32 +459,55 @@ int load_uimage(const char *filename, hwaddr *ep,
     if (hdr->ih_magic != IH_MAGIC)
         goto out;
 
-    /* TODO: Implement other image types.  */
-    if (hdr->ih_type != IH_TYPE_KERNEL) {
-        fprintf(stderr, "Can only load u-boot image type \"kernel\"\n");
+    if (hdr->ih_type != image_type) {
+        fprintf(stderr, "Wrong image type %d, expected %d\n", hdr->ih_type,
+                image_type);
         goto out;
     }
 
-    switch (hdr->ih_comp) {
-    case IH_COMP_NONE:
-    case IH_COMP_GZIP:
+    /* TODO: Implement other image types.  */
+    switch (hdr->ih_type) {
+    case IH_TYPE_KERNEL:
+        address = hdr->ih_load;
+        if (loadaddr) {
+            *loadaddr = hdr->ih_load;
+        }
+
+        switch (hdr->ih_comp) {
+        case IH_COMP_NONE:
+            break;
+        case IH_COMP_GZIP:
+            do_uncompress = 1;
+            break;
+        default:
+            fprintf(stderr,
+                    "Unable to load u-boot images with compression type %d\n",
+                    hdr->ih_comp);
+            goto out;
+        }
+
+        if (ep) {
+            *ep = hdr->ih_ep;
+        }
+
+        /* TODO: Check CPU type.  */
+        if (is_linux) {
+            if (hdr->ih_os == IH_OS_LINUX) {
+                *is_linux = 1;
+            } else {
+                *is_linux = 0;
+            }
+        }
+
+        break;
+    case IH_TYPE_RAMDISK:
+        address = *loadaddr;
         break;
     default:
-        fprintf(stderr,
-                "Unable to load u-boot images with compression type %d\n",
-                hdr->ih_comp);
+        fprintf(stderr, "Unsupported u-boot image type %d\n", hdr->ih_type);
         goto out;
     }
 
-    /* TODO: Check CPU type.  */
-    if (is_linux) {
-        if (hdr->ih_os == IH_OS_LINUX)
-            *is_linux = 1;
-        else
-            *is_linux = 0;
-    }
-
-    *ep = hdr->ih_ep;
     data = g_malloc(hdr->ih_size);
 
     if (read(fd, data, hdr->ih_size) != hdr->ih_size) {
@@ -490,7 +515,7 @@ int load_uimage(const char *filename, hwaddr *ep,
         goto out;
     }
 
-    if (hdr->ih_comp == IH_COMP_GZIP) {
+    if (do_uncompress) {
         uint8_t *compressed_data;
         size_t max_bytes;
         ssize_t bytes;
@@ -508,10 +533,7 @@ int load_uimage(const char *filename, hwaddr *ep,
         hdr->ih_size = bytes;
     }
 
-    rom_add_blob_fixed(filename, data, hdr->ih_size, hdr->ih_load);
-
-    if (loadaddr)
-        *loadaddr = hdr->ih_load;
+    rom_add_blob_fixed(filename, data, hdr->ih_size, address);
 
     ret = hdr->ih_size;
 
@@ -522,6 +544,18 @@ out:
     return ret;
 }
 
+int load_uimage(const char *filename, hwaddr *ep, hwaddr *loadaddr,
+                int *is_linux)
+{
+    return load_uboot_image(filename, ep, loadaddr, is_linux, IH_TYPE_KERNEL);
+}
+
+/* Load a ramdisk.  */
+int load_ramdisk(const char *filename, hwaddr addr, uint64_t max_sz)
+{
+    return load_uboot_image(filename, NULL, &addr, NULL, IH_TYPE_RAMDISK);
+}
+
 /*
  * 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 15d4cc9..eb9c9a3 100644
--- a/include/hw/loader.h
+++ b/include/hw/loader.h
@@ -17,6 +17,19 @@ int load_aout(const char *filename, hwaddr addr, int max_sz,
 int load_uimage(const char *filename, hwaddr *ep,
                 hwaddr *loadaddr, int *is_linux);
 
+/**
+ * load_ramdisk:
+ * @filename: Path to the ramdisk image
+ * @addr: Memory address to load the ramdisk to
+ * @max_sz: Maximum allowed ramdisk size (for non-u-boot ramdisks)
+ *
+ * Load a ramdisk image with U-Boot header to the specified memory
+ * address.
+ *
+ * Returns the size of the loaded image on success, -1 otherwise.
+ */
+int load_ramdisk(const char *filename, hwaddr addr, uint64_t max_sz);
+
 ssize_t read_targphys(const char *name,
                       int fd, hwaddr dst_addr, size_t nbytes);
 void pstrcpy_targphys(const char *name,
-- 
1.8.3.2