[U-Boot] [PATCH v2 6/9] x86: Support relocation of FDT on start-up

[Simon Glass]

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 at chromium.org>
---
Changes in v2:
- Use arch-specific data for new fdt pointer

 arch/x86/include/asm/global_data.h  |  1 +
 arch/x86/include/asm/init_helpers.h |  2 ++
 arch/x86/include/asm/relocate.h     |  1 +
 arch/x86/lib/board.c                |  3 +++
 arch/x86/lib/init_helpers.c         | 23 +++++++++++++++++++++--
 arch/x86/lib/init_wrappers.c        |  1 +
 arch/x86/lib/relocate.c             | 17 +++++++++++++++++
 7 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/global_data.h b/arch/x86/include/asm/global_data.h
index 2f84abd..4fdb080 100644
--- a/arch/x86/include/asm/global_data.h
+++ b/arch/x86/include/asm/global_data.h
@@ -32,6 +32,7 @@ struct arch_global_data {
 	uint64_t tsc_base;		/* Initial value returned by rdtsc() */
 	uint32_t tsc_base_kclocks;	/* Initial tsc as a kclocks value */
 	uint32_t tsc_prev;		/* For show_boot_progress() */
+	void *new_fdt;			/* Relocated FDT */
 };
 
 #endif
diff --git a/arch/x86/include/asm/init_helpers.h b/arch/x86/include/asm/init_helpers.h
index 2f437e0..d018b29 100644
--- a/arch/x86/include/asm/init_helpers.h
+++ b/arch/x86/include/asm/init_helpers.h
@@ -38,5 +38,7 @@ int flash_init_r(void);
 int status_led_set_r(void);
 int set_load_addr_r(void);
 int init_func_spi(void);
+int find_fdt(void);
+int prepare_fdt(void);
 
 #endif	/* !_INIT_HELPERS_H_ */
diff --git a/arch/x86/include/asm/relocate.h b/arch/x86/include/asm/relocate.h
index 33129ef..d371c9d 100644
--- a/arch/x86/include/asm/relocate.h
+++ b/arch/x86/include/asm/relocate.h
@@ -27,6 +27,7 @@
 #include <common.h>
 
 int copy_uboot_to_ram(void);
+int copy_fdt_to_ram(void);
 int clear_bss(void);
 int do_elf_reloc_fixups(void);
 
diff --git a/arch/x86/lib/board.c b/arch/x86/lib/board.c
index 22bc26d..2441a66 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 ff2d21f..414fdcc 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 cca018f..19af875 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 23edca9..3a38e52 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;
-- 
1.8.1.3