Support separate DTB files with the UEFI app

The UEFI app is an actual executable with things like section headers,
so just gluing the DTB onto the end of it won't work. Add an additional
section to contain this and allocate some space, and then during build
copy the DTB into that section.

Signed-off-by: Matthew Garrett <mgarrett@aurora.tech>
Reviewed-by: Simon Glass <sjg@chromium.org>

Makefile

@@ -1067,6 +1067,10 @@ quiet_cmd_objcopy = OBJCOPY $@
 cmd_objcopy = $(OBJCOPY) --gap-fill=0xff $(OBJCOPYFLAGS) \
 	$(OBJCOPYFLAGS_$(@F)) $< $@
 
+# Inject the DTB into u-boot
+quiet_cmd_embeddtb = OBJCOPY $@
+cmd_embeddtb = $(OBJCOPY) --update-section .embedded_dtb=dts/dt.dtb --set-section-flags .embedded_dtb=contents,alloc,load,data $<
+
 # Provide a version which does not do this, for use by EFI
 quiet_cmd_zobjcopy = OBJCOPY $@
 cmd_zobjcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
@@ -1673,7 +1677,8 @@ u-boot-x86-reset16.bin: u-boot FORCE
 endif # CONFIG_X86
 
 OBJCOPYFLAGS_u-boot-app.efi := $(OBJCOPYFLAGS_EFI)
-u-boot-app.efi: u-boot FORCE
+u-boot-app.efi: u-boot dts/dt.dtb FORCE
+	$(call if_changed,embeddtb)
 	$(call if_changed,zobjcopy)
 
 u-boot.bin.o: u-boot.bin FORCE

arch/x86/config.mk

@@ -45,7 +45,7 @@ LDFLAGS_EFI_PAYLOAD := -Bsymbolic -Bsymbolic-functions -shared --no-undefined \
 		       -s -zexecstack
 
 OBJCOPYFLAGS_EFI := -j .text -j .sdata -j .data -j .dynamic -j .dynsym \
-	-j .rel -j .rela -j .reloc --strip-all
+	-j .rel -j .rela -j .reloc -j .embedded_dtb --strip-all
 
 # Compiler flags to be added when building UEFI applications
 CFLAGS_EFI := -fpic -fshort-wchar

arch/x86/lib/elf_x86_64_efi.lds

@@ -79,5 +79,9 @@ SECTIONS
 		*(.note.GNU-stack)
 	}
 
+	.embedded_dtb : {
+		*(.embedded_dtb)
+	}
+
 	.comment 0 : { *(.comment) }
 }

include/asm-generic/sections.h

@@ -70,6 +70,7 @@ extern char __image_copy_start[], __image_copy_end[];
 extern char __bss_end[];
 extern char __rel_dyn_start[], __rel_dyn_end[];
 extern char _image_binary_end[];
+extern char _dtb[];
 
 /*
  * This is the U-Boot entry point - prior to relocation it should be same

lib/efi/Makefile

@@ -2,7 +2,7 @@
 #
 # (C) Copyright 2015 Google, Inc
 
-obj-$(CONFIG_EFI_APP) += efi_app.o efi.o efi_app_init.o efi_vars.o
+obj-$(CONFIG_EFI_APP) += efi_app.o efi.o efi_app_init.o efi_vars.o efi_dtb.o
 obj-$(CONFIG_EFI_STUB) += efi_info.o
 
 CFLAGS_REMOVE_efi_stub.o := -mregparm=3 \

lib/efi/efi_dtb.S

@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifdef CONFIG_OF_SEPARATE
+.section .embedded_dtb, "a"
+.globl __dtb
+__dtb: .fill 1024*1024
+#endif

lib/fdtdec.c

@@ -1236,6 +1236,9 @@ static void *fdt_find_separate(void)
 		fdt_blob = (ulong *)_image_binary_end;
 	else
 		fdt_blob = (ulong *)__bss_end;
+#elif defined CONFIG_EFI_APP
+	/* FDT is in a separate section */
+	fdt_blob = (ulong *)__dtb;
 #else
 	/* FDT is at end of image */
 	fdt_blob = (ulong *)_end;