openrisc: enable passing of flattened device tree pointer

This patch enables passing a fdt pointer to the kernel.

This makes for the kernel parameter API:

void kernel(unsigned int fdt);

which, in accordance with the OpenRISC ABI results in:
r3 = pointer to fdt

Signed-off-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Signed-off-by: Jonas Bonn <jonas@southpole.se>

1 files changed, 9 insertions, 9 deletions

diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
index 1422f747f52b..bf5eba22ce9e 100644
--- a/arch/openrisc/kernel/setup.c
+++ b/arch/openrisc/kernel/setup.c
@@ -207,18 +207,18 @@ void __init setup_cpuinfo(void)
  * Handles the pointer to the device tree that this kernel is to use
  * for establishing the available platform devices.
  *
- * For now, this is limited to using the built-in device tree.  In the future,
- * it is intended that this function will take a pointer to the device tree
- * that is potentially built-in, but potentially also passed in by the
- * bootloader, or discovered by some equally clever means...
+ * Falls back on built-in device tree in case null pointer is passed.
  */
 
-void __init or32_early_setup(void)
+void __init or32_early_setup(unsigned int fdt)
 {
-
-        early_init_devtree(__dtb_start);
-
-        printk(KERN_INFO "Compiled-in FDT at 0x%p\n", __dtb_start);
+        if (fdt) {
+                early_init_devtree((void*) fdt);
+                printk(KERN_INFO "FDT at 0x%08x\n", fdt);
+        } else {
+                early_init_devtree(__dtb_start);
+                printk(KERN_INFO "Compiled-in FDT at %p\n", __dtb_start);
+        }
 }
 
 static int __init openrisc_device_probe(void)