x86: Support relocation of FDT on start-up

With CONFIG_OF_CONTROL we may have an FDT in the BSS region. Relocate
it up with the rest of U-Boot to keep the rest of memory free.

Signed-off-by: Simon Glass <sjg@chromium.org>

4 files changed, 42 insertions, 2 deletions

diff --git a/arch/x86/lib/board.c b/arch/x86/lib/board.c
index 22bc26dde9..2441a66ae2 100644
--- a/arch/x86/lib/board.c
+++ b/arch/x86/lib/board.c
@@ -32,6 +32,7 @@
  */
 
 #include <common.h>
+#include <fdtdec.h>
 #include <watchdog.h>
 #include <stdio_dev.h>
 #include <asm/u-boot-x86.h>
@@ -131,6 +132,7 @@ init_fnc_t *init_sequence_f[] = {
 init_fnc_t *init_sequence_f_r[] = {
 	init_cache_f_r,
 	copy_uboot_to_ram,
+	copy_fdt_to_ram,
 	clear_bss,
 	do_elf_reloc_fixups,
 
@@ -217,6 +219,7 @@ static void do_init_loop(init_fnc_t **init_fnc_ptr)
 
 void board_init_f(ulong boot_flags)
 {
+	gd->fdt_blob = gd->arch.new_fdt = NULL;
 	gd->flags = boot_flags;
 
 	do_init_loop(init_sequence_f);
diff --git a/arch/x86/lib/init_helpers.c b/arch/x86/lib/init_helpers.c
index ff2d21f4c5..414fdcc4c9 100644
--- a/arch/x86/lib/init_helpers.c
+++ b/arch/x86/lib/init_helpers.c
@@ -22,6 +22,7 @@
  */
 #include <common.h>
 #include <command.h>
+#include <fdtdec.h>
 #include <stdio_dev.h>
 #include <version.h>
 #include <malloc.h>
@@ -85,17 +86,35 @@ int calculate_relocation_address(void)
 			(uintptr_t)&__text_start;
 	ulong total_size;
 	ulong dest_addr;
+	ulong fdt_size = 0;
 
+#if defined(CONFIG_OF_SEPARATE) && defined(CONFIG_OF_CONTROL)
+	if (gd->fdt_blob)
+		fdt_size = ALIGN(fdt_totalsize(gd->fdt_blob) + 0x1000, 32);
+#endif
 	total_size = ALIGN(uboot_size, 1 << 12) + CONFIG_SYS_MALLOC_LEN +
-		CONFIG_SYS_STACK_SIZE;
+		CONFIG_SYS_STACK_SIZE + fdt_size;
 
+	dest_addr = board_get_usable_ram_top(total_size);
 	/*
 	 * NOTE: All destination address are rounded down to 16-byte
 	 *       boundary to satisfy various worst-case alignment
 	 *       requirements
 	 */
-	dest_addr = board_get_usable_ram_top(total_size);
+	dest_addr &= ~15;
 
+#if defined(CONFIG_OF_SEPARATE) && defined(CONFIG_OF_CONTROL)
+	/*
+	 * If the device tree is sitting immediate above our image then we
+	 * must relocate it. If it is embedded in the data section, then it
+	 * will be relocated with other data.
+	 */
+	if (gd->fdt_blob) {
+		dest_addr -= fdt_size;
+		gd->arch.new_fdt = (void *)dest_addr;
+		dest_addr &= ~15;
+	}
+#endif
 	/* U-Boot is below the FDT */
 	dest_addr -= uboot_size;
 	dest_addr &= ~((1 << 12) - 1);
diff --git a/arch/x86/lib/init_wrappers.c b/arch/x86/lib/init_wrappers.c
index cca018fa9b..19af875c0e 100644
--- a/arch/x86/lib/init_wrappers.c
+++ b/arch/x86/lib/init_wrappers.c
@@ -22,6 +22,7 @@
  */
 #include <common.h>
 #include <environment.h>
+#include <fdtdec.h>
 #include <serial.h>
 #include <kgdb.h>
 #include <scsi.h>
diff --git a/arch/x86/lib/relocate.c b/arch/x86/lib/relocate.c
index 23edca9526..3a38e52ac9 100644
--- a/arch/x86/lib/relocate.c
+++ b/arch/x86/lib/relocate.c
@@ -32,6 +32,7 @@
  */
 
 #include <common.h>
+#include <libfdt.h>
 #include <malloc.h>
 #include <asm/u-boot-x86.h>
 #include <asm/relocate.h>
@@ -46,6 +47,22 @@ int copy_uboot_to_ram(void)
 	return 0;
 }
 
+int copy_fdt_to_ram(void)
+{
+	if (gd->arch.new_fdt) {
+		ulong fdt_size;
+
+		fdt_size = ALIGN(fdt_totalsize(gd->fdt_blob) + 0x1000, 32);
+
+		memcpy(gd->arch.new_fdt, gd->fdt_blob, fdt_size);
+		debug("Relocated fdt from %p to %p, size %lx\n",
+		       gd->fdt_blob, gd->arch.new_fdt, fdt_size);
+		gd->fdt_blob = gd->arch.new_fdt;
+	}
+
+	return 0;
+}
+
 int clear_bss(void)
 {
 	ulong dst_addr = (ulong)&__bss_start + gd->reloc_off;