[Qemu-devel] [PATCH v2 1/2] ARM: Allow boards to provide an fdt blob

[John Rigby <john.rigby@linaro.org>]

If no fdt is provided on command line and the new field
get_dtb in struct arm_boot_info is set then call it to
get a device tree blob.

Also allow dumping of device tree by calling qemu_devtree_dumpdtb
near the end of load_dtb.

Signed-off-by: John Rigby <john.rigby@linaro.org>
---
 hw/arm/boot.c        |   31 ++++++++++++++++++++-----------
 include/hw/arm/arm.h |    6 ++++++
 2 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index f451529..de71edf 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -235,19 +235,27 @@ static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo)
     int size, rc;
     uint32_t acells, scells, hival;
 
-    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, binfo->dtb_filename);
-    if (!filename) {
-        fprintf(stderr, "Couldn't open dtb file %s\n", binfo->dtb_filename);
-        return -1;
-    }
+    if (binfo->dtb_filename) {
+        filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, binfo->dtb_filename);
+        if (!filename) {
+            fprintf(stderr, "Couldn't open dtb file %s\n", binfo->dtb_filename);
+            return -1;
+        }
 
-    fdt = load_device_tree(filename, &size);
-    if (!fdt) {
-        fprintf(stderr, "Couldn't open dtb file %s\n", filename);
+        fdt = load_device_tree(filename, &size);
+        if (!fdt) {
+            fprintf(stderr, "Couldn't open dtb file %s\n", filename);
+            g_free(filename);
+            return -1;
+        }
         g_free(filename);
-        return -1;
+    } else if (binfo->get_dtb) {
+        fdt = binfo->get_dtb(addr, binfo, &size);
+        if (!fdt) {
+            fprintf(stderr, "Couldn't get dtb blob from board func\n");
+            return -1;
+        }
     }
-    g_free(filename);
 
     acells = qemu_devtree_getprop_cell(fdt, "/", "#address-cells");
     scells = qemu_devtree_getprop_cell(fdt, "/", "#size-cells");
@@ -304,6 +312,7 @@ static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo)
             fprintf(stderr, "couldn't set /chosen/linux,initrd-end\n");
         }
     }
+    qemu_devtree_dumpdtb(fdt, size);
 
     cpu_physical_memory_write(addr, fdt, size);
 
@@ -440,7 +449,7 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
         /* for device tree boot, we pass the DTB directly in r2. Otherwise
          * we point to the kernel args.
          */
-        if (info->dtb_filename) {
+        if (info->dtb_filename || info->get_dtb) {
             /* Place the DTB after the initrd in memory. Note that some
              * kernels will trash anything in the 4K page the initrd
              * ends in, so make sure the DTB isn't caught up in that.
diff --git a/include/hw/arm/arm.h b/include/hw/arm/arm.h
index 7b2b02d..4c56a1b 100644
--- a/include/hw/arm/arm.h
+++ b/include/hw/arm/arm.h
@@ -31,6 +31,10 @@ struct arm_boot_info {
     const char *kernel_cmdline;
     const char *initrd_filename;
     const char *dtb_filename;
+    /* if a board is able to create a dtb without a dtb file then it
+     * sets get_dtb.  This will only be used if no dtb file is provided.
+     */
+    void *(*get_dtb)(hwaddr addr, const struct arm_boot_info *binfo, int *size);
     hwaddr loader_start;
     /* multicore boards that use the default secondary core boot functions
      * need to put the address of the secondary boot code, the boot reg,
@@ -59,6 +63,8 @@ struct arm_boot_info {
     int is_linux;
     hwaddr initrd_start;
     hwaddr initrd_size;
+    void *dtb_blob;
+    int dtb_blob_size;
     hwaddr entry;
 };
 void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info);
-- 
1.7.9.5