x86: zImage: Pass working device tree data to the kernel

On x86 platforms, U-Boot does not pass Device Tree data to the kernel.
This prevents the kernel from using FDT loaded by U-Boot.

Read the working FDT address from the "fdtaddr" environment variable
and add a copy of the FDT data to the kernel setup_data list.

Signed-off-by: Ivan Gorinov <ivan.gorinov@intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
[bmeng: add #include <linux/libfdt.h> to zimage.c to fix build error]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/include/asm/bootparam.h

@@ -10,8 +10,11 @@
 #include <asm/video/edid.h>
 
 /* setup data types */
-#define SETUP_NONE			0
-#define SETUP_E820_EXT			1
+enum {
+	SETUP_NONE = 0,
+	SETUP_E820_EXT,
+	SETUP_DTB,
+};
 
 /* extensible setup data list node */
 struct setup_data {

arch/x86/lib/zimage.c

@@ -14,6 +14,7 @@
  */
 
 #include <common.h>
+#include <malloc.h>
 #include <asm/acpi_table.h>
 #include <asm/io.h>
 #include <asm/ptrace.h>
@@ -25,6 +26,7 @@
 #include <asm/arch/timestamp.h>
 #endif
 #include <linux/compiler.h>
+#include <linux/libfdt.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -95,6 +97,38 @@ static int get_boot_protocol(struct setup_header *hdr)
 	}
 }
 
+static int setup_device_tree(struct setup_header *hdr, const void *fdt_blob)
+{
+	int bootproto = get_boot_protocol(hdr);
+	struct setup_data *sd;
+	int size;
+
+	if (bootproto < 0x0209)
+		return -ENOTSUPP;
+
+	if (!fdt_blob)
+		return 0;
+
+	size = fdt_totalsize(fdt_blob);
+	if (size < 0)
+		return -EINVAL;
+
+	size += sizeof(struct setup_data);
+	sd = (struct setup_data *)malloc(size);
+	if (!sd) {
+		printf("Not enough memory for DTB setup data\n");
+		return -ENOMEM;
+	}
+
+	sd->next = hdr->setup_data;
+	sd->type = SETUP_DTB;
+	sd->len = fdt_totalsize(fdt_blob);
+	memcpy(sd->data, fdt_blob, sd->len);
+	hdr->setup_data = (unsigned long)sd;
+
+	return 0;
+}
+
 struct boot_params *load_zimage(char *image, unsigned long kernel_size,
 				ulong *load_addressp)
 {
@@ -261,6 +295,7 @@ int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot,
 		hdr->acpi_rsdp_addr = acpi_get_rsdp_addr();
 #endif
 
+	setup_device_tree(hdr, (const void *)env_get_hex("fdtaddr", 0));
 	setup_video(&setup_base->screen_info);
 
 	return 0;