Merge patch series "Update linker scripts to ensure appended device tree is correctly aligned"

Tom Rini <trini@konsulko.com> says:

This series builds on top of what Beleswar Padhi did in [1]. While
there's still discussion about the mkimage related parts, the linker
portion appears to the reliable path forward. An alternative that I had
mentioned before, and was part of previous discussions on this topic[2]
is in the end I believe not reliable enough. While we can take an output
file and pad it to where we think it needs to be, ultimately the linker
needs to place the symbol where we want it and if that isn't where we
pad to, we have a different problem. So what this series does (but each
commit message elaborates on the arch-specific linker scripts being
inconsistent) is make sure the linker script will place the required
symbol at 8-byte alignment, and then also use an ASSERT to fail the
build if this would not be true due to some unforseen event.

[1]: https://lore.kernel.org/u-boot/20260112101102.1417970-1-b-padhi@ti.com/
[2]: https://source.denx.de/u-boot/u-boot/-/issues/30

Link: https://lore.kernel.org/r/20260115222828.3931345-1-trini@konsulko.com

Makefile

@@ -1583,7 +1583,7 @@ binary_size_check: u-boot-nodtb.bin FORCE
 	map_size=$(shell cat u-boot.map | \
 		awk ' \
 			/_image_copy_start/ { start = $$1 } \
-			/_image_binary_end/ { end = $$1 } \
+			/_image_binary_end/ { end = $$1;exit } \
 			END { \
 				if (start != "" && end != "") \
 					print end " " start; \

arch/arm/cpu/arm1136/u-boot-spl.lds

@@ -30,8 +30,10 @@ SECTIONS
 	.rodata : { *(SORT_BY_ALIGNMENT(.rodata*)) } >.sram
 
 	. = ALIGN(4);
-	.data : { *(SORT_BY_ALIGNMENT(.data*)) } >.sram
-	. = ALIGN(4);
+	.data : {
+		*(SORT_BY_ALIGNMENT(.data*))
+		. = ALIGN(8);
+	} >.sram
 	__image_copy_end = .;
 	_end = .;
 
@@ -44,3 +46,5 @@ SECTIONS
 		__bss_end = .;
 	} >.sdram
 }
+
+ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");

arch/arm/cpu/arm926ejs/mxs/u-boot-spl.lds

@@ -45,7 +45,7 @@ SECTIONS
 		. = ALIGN(4);
 		__bss_start = .;
 		*(.bss*)
-		. = ALIGN(4);
+		. = ALIGN(8);
 		__bss_end = .;
 	}
 
@@ -62,3 +62,6 @@ SECTIONS
 	.gnu : { *(.gnu*) }
 	.ARM.exidx : { *(.ARM.exidx*) }
 }
+
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");

arch/arm/cpu/arm926ejs/sunxi/u-boot-spl.lds

@@ -31,9 +31,9 @@ SECTIONS
 	. = ALIGN(4);
 	__u_boot_list : {
 		KEEP(*(SORT(__u_boot_list*)));
+		. = ALIGN(8);
 	} > .sram
 
-	. = ALIGN(4);
 	__image_copy_end = .;
 	_end = .;
 	_image_binary_end = .;
@@ -47,3 +47,6 @@ SECTIONS
 		__bss_end = .;
 	} > .sdram
 }
+
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");

arch/arm/cpu/armv7/sunxi/u-boot-spl.lds

@@ -40,9 +40,9 @@ SECTIONS
 	. = ALIGN(4);
 	__u_boot_list : {
 		KEEP(*(SORT(__u_boot_list*)));
+		. = ALIGN(8);
 	} > .sram
 
-	. = ALIGN(4);
 	__image_copy_end = .;
 	_end = .;
 	_image_binary_end = .;
@@ -56,3 +56,6 @@ SECTIONS
 		__bss_end = .;
 	} > .sdram
 }
+
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");

arch/arm/cpu/armv8/u-boot-spl.lds

@@ -52,9 +52,9 @@ SECTIONS
 	__u_boot_list : {
 		. = ALIGN(8);
 		KEEP(*(SORT(__u_boot_list*)));
+		. = ALIGN(8);
 	} >.sram
 
-	. = ALIGN(8);
 	__image_copy_end = .;
 	_end = .;
 	_image_binary_end = .;
@@ -89,5 +89,7 @@ SECTIONS
 #endif
 }
 
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");
 ASSERT(ADDR(.bss) % 8 == 0, \
        ".bss must be 8-byte aligned");

arch/arm/cpu/armv8/u-boot.lds

@@ -146,6 +146,7 @@ SECTIONS
 		__rel_dyn_start = .;
 		*(.rela*)
 		__rel_dyn_end = .;
+		. = ALIGN(8);
 	}
 
 	_end = .;
@@ -175,3 +176,5 @@ SECTIONS
 #include "linux-kernel-image-header-vars.h"
 #endif
 }
+
+ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");

arch/arm/cpu/u-boot-spl.lds

@@ -51,9 +51,9 @@ SECTIONS
 		__rel_dyn_start = .;
 		*(.rel*)
 		__rel_dyn_end = .;
+		. = ALIGN(8);
 	}
 
-	. = ALIGN(8);
 	_image_binary_end = .;
 	_end = .;
 
@@ -80,6 +80,9 @@ ASSERT(__image_copy_end - __image_copy_start <= (IMAGE_MAX_SIZE), \
 	"SPL image too big");
 #endif
 
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");
+
 #if defined(CONFIG_SPL_BSS_MAX_SIZE)
 ASSERT(__bss_end - __bss_start <= (CONFIG_SPL_BSS_MAX_SIZE), \
 	"SPL image BSS too big");

arch/arm/cpu/u-boot.lds

@@ -164,6 +164,7 @@ SECTIONS
 		__rel_dyn_start = .;
 		*(.rel*)
 		__rel_dyn_end = .;
+		. = ALIGN(8);
 	}
 
 	_end = .;
@@ -192,3 +193,6 @@ SECTIONS
 	/DISCARD/ : { *(.ARM.exidx*) }
 	/DISCARD/ : { *(.gnu.linkonce.armexidx.*) }
 }
+
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");

arch/arm/mach-aspeed/ast2600/u-boot-spl.lds

@@ -59,6 +59,7 @@ SECTIONS
 		__rel_dyn_start = .;
 		*(.rel*)
 		__rel_dyn_end = .;
+		. = ALIGN(8);
 	} > .nor
 
 	_end = .;
@@ -79,6 +80,9 @@ ASSERT(__image_copy_end - __image_copy_start <= (IMAGE_MAX_SIZE), \
 	"SPL image too big");
 #endif
 
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");
+
 #if defined(CONFIG_SPL_BSS_MAX_SIZE)
 ASSERT(__bss_end - __bss_start <= (CONFIG_SPL_BSS_MAX_SIZE), \
 	"SPL image BSS too big");

arch/arm/mach-at91/arm926ejs/u-boot-spl.lds

@@ -29,9 +29,11 @@ SECTIONS
 	.data : { *(SORT_BY_ALIGNMENT(.data*)) } >.sram
 
 	. = ALIGN(4);
-	__u_boot_list : { KEEP(*(SORT(__u_boot_list*))) } > .sram
+	__u_boot_list : {
+		KEEP(*(SORT(__u_boot_list*)))
+		. = ALIGN(8);
+	} > .sram
 
-	. = ALIGN(4);
 	__image_copy_end = .;
 	_end = .;
 	_image_binary_end = .;
@@ -51,6 +53,9 @@ ASSERT(__image_copy_end - __start <= (IMAGE_MAX_SIZE), \
 	"SPL image too big");
 #endif
 
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");
+
 #if defined(CONFIG_SPL_BSS_MAX_SIZE)
 ASSERT(__bss_end - __bss_start <= (CONFIG_SPL_BSS_MAX_SIZE), \
 	"SPL image BSS too big");

arch/arm/mach-at91/armv7/u-boot-spl.lds

@@ -36,9 +36,11 @@ SECTIONS
 	.data : { *(SORT_BY_ALIGNMENT(.data*)) } >.sram
 
 	. = ALIGN(4);
-	__u_boot_list : { KEEP(*(SORT(__u_boot_list*))) } > .sram
+	__u_boot_list : {
+		KEEP(*(SORT(__u_boot_list*)))
+		. = ALIGN(8);
+	} > .sram
 
-	. = ALIGN(4);
 	__image_copy_end = .;
 	_end = .;
 	_image_binary_end = .;
@@ -52,3 +54,6 @@ SECTIONS
 		__bss_end = .;
 	} >.sdram
 }
+
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");

arch/arm/mach-omap2/u-boot-spl.lds

@@ -55,3 +55,6 @@ SECTIONS
 		__bss_end = .;
 	} >.sdram
 }
+
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");

arch/arm/mach-rockchip/u-boot-tpl-v8.lds

@@ -42,9 +42,9 @@ SECTIONS
 	__u_boot_list : {
 		. = ALIGN(8);
 		KEEP(*(SORT(__u_boot_list*)));
+		. = ALIGN(8);
 	}
 
-	. = ALIGN(8);
 	__image_copy_end = .;
 	_end = .;
 	_image_binary_end = .;
@@ -69,6 +69,9 @@ ASSERT(__image_copy_end - __image_copy_start < (CONFIG_TPL_MAX_SIZE), \
 	"TPL image too big");
 #endif
 
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");
+
 #if defined(CONFIG_TPL_BSS_MAX_SIZE)
 ASSERT(__bss_end - __bss_start < (CONFIG_TPL_BSS_MAX_SIZE), \
 	"TPL image BSS too big");

arch/arm/mach-zynq/u-boot-spl.lds

@@ -39,10 +39,9 @@ SECTIONS
 	. = ALIGN(4);
 	__u_boot_list : {
 		KEEP(*(SORT(__u_boot_list*)));
+		. = ALIGN(8);
 	} > .sram
 
-	. = ALIGN(4);
-
 	_image_binary_end = .;
 
 	_end = .;
@@ -62,3 +61,6 @@ SECTIONS
 	/DISCARD/ : { *(.interp*) }
 	/DISCARD/ : { *(.gnu*) }
 }
+
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");

arch/arm/mach-zynq/u-boot.lds

@@ -66,6 +66,7 @@ SECTIONS
 		__rel_dyn_start = .;
 		*(.rel*)
 		__rel_dyn_end = .;
+		. = ALIGN(8);
 	}
 
 	_end = .;
@@ -98,3 +99,5 @@ SECTIONS
 	/DISCARD/ : { *(.ARM.exidx*) }
 	/DISCARD/ : { *(.gnu.linkonce.armexidx.*) }
 }
+
+ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");

arch/m68k/cpu/u-boot.lds

@@ -69,28 +69,27 @@ SECTIONS
 	__ex_table : { *(__ex_table) }
 	__stop___ex_table = .;
 
-	. = ALIGN(8);
+	. = ALIGN(4);
 	__init_begin = .;
 	.text.init : { *(.text.init) }
 	.data.init : { *(.data.init) }
-	. = ALIGN(8);
+	. = ALIGN(4);
 	__init_end = .;
 
-	. = ALIGN(8);
+	. = ALIGN(4);
 	__rel_dyn_start = .;
 	.rela.dyn : {
 		*(.rela.dyn)
 	}
 	__rel_dyn_end = .;
 
-	. = ALIGN(8);
-	__dyn_sym_start = .;
-	.dynsym : {
+	.dynsym ALIGN(4) : {
+		__dyn_sym_start = .;
 		*(.dynsym)
+		__dyn_sym_end = .;
+		. = ALIGN(8);
 	}
-	__dyn_sym_end = .;
 
-	. = ALIGN(8);
 	_end = .;
 
 	__bss_start = .;
@@ -100,9 +99,11 @@ SECTIONS
 		*(.bss*)
 		*(.sbss*)
 		*(COMMON)
-		. = ALIGN(8);
+		. = ALIGN(4);
 		_ebss = .;
 	}
 	__bss_end = . ;
 	PROVIDE (end = .);
 }
+
+ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");

arch/microblaze/cpu/u-boot-spl.lds

@@ -50,7 +50,7 @@ SECTIONS
 		*(.bss)
 		*(.bss.*)
 		*(COMMON)
-		. = ALIGN(4);
+		. = ALIGN(8);
 		__bss_end = .;
 	}
 	_end = . ;
@@ -61,3 +61,6 @@ SECTIONS
 ASSERT(_end - _start <= (CONFIG_SPL_MAX_FOOTPRINT), \
         "SPL image plus BSS too big");
 #endif
+
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");

arch/microblaze/cpu/u-boot.lds

@@ -67,8 +67,10 @@ SECTIONS
 		*(.scommon)
 		*(.bss*)
 		*(COMMON)
-		. = ALIGN(4);
+		. = ALIGN(8);
 		__bss_end = .;
 	}
 	_end = . ;
 }
+
+ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");

arch/mips/cpu/u-boot-spl.lds

@@ -27,16 +27,17 @@ SECTIONS
 	.data : {
 		*(SORT_BY_ALIGNMENT(.data*))
 		*(SORT_BY_ALIGNMENT(.sdata*))
+		. = ALIGN(8);
 	} > .spl_mem
 
 #if defined(CONFIG_SPL_DM) || defined(CONFIG_SPL_LOADER_SUPPORT)
 	. = ALIGN(4);
 	__u_boot_list : {
 		KEEP(*(SORT(__u_boot_list*)));
+		. = ALIGN(8);
 	} > .spl_mem
 #endif
 
-	. = ALIGN(4);
 	__image_copy_end = .;
 	__image_copy_len = __image_copy_end - __text_start;
 
@@ -123,3 +124,6 @@ SECTIONS
 		*(.eh_frame)
 	}
 }
+
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");

arch/mips/cpu/u-boot.lds

@@ -54,9 +54,9 @@ SECTIONS
 		LONG(0xFFFFFFFF);
 		FILL(0);
 		. += CONFIG_MIPS_RELOCATION_TABLE_SIZE - 4;
+		. = ALIGN(8);
 	}
 
-	. = ALIGN(8);
 	_end = .;
 
 	.bss __rel_start (OVERLAY) : {
@@ -140,3 +140,5 @@ SECTIONS
 		*(.eh_frame)
 	}
 }
+
+ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");

arch/nios2/cpu/u-boot.lds

@@ -60,8 +60,8 @@ SECTIONS
 	  *(.sdata)
 	  *(.sdata.*)
 	  *(.gnu.linkonce.s.*)
+	  . = ALIGN(8);
 	}
-	. = ALIGN(4);
 
 	_edata = .;
 	PROVIDE (edata = .);
@@ -124,3 +124,5 @@ SECTIONS
 	.debug_typenames 0 : { *(.debug_typenames) }
 	.debug_varnames	 0 : { *(.debug_varnames) }
 }
+
+ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");

arch/powerpc/cpu/mpc83xx/u-boot.lds

@@ -56,6 +56,7 @@ SECTIONS
    * _end - This is end of u-boot.bin image.
    * dtb will be appended here to make u-boot-dtb.bin
    */
+  . = ALIGN(8);
   _end = .;
 
   . = ALIGN(4096);
@@ -77,3 +78,5 @@ SECTIONS
   PROVIDE (end = .);
 }
 ENTRY(_start)
+
+ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");

arch/powerpc/cpu/mpc85xx/u-boot.lds

@@ -78,7 +78,7 @@ SECTIONS
   __init_begin = .;
   .text.init : { *(.text.init) }
   .data.init : { *(.data.init) }
-  . = ALIGN(4);
+  . = ALIGN(8);
   __init_end = .;
   _end = .;
 
@@ -119,3 +119,5 @@ SECTIONS
   __bss_end = . ;
   PROVIDE (end = .);
 }
+
+ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");

arch/riscv/cpu/u-boot-spl.lds

@@ -43,6 +43,7 @@ SECTIONS
 		__binman_sym_start = .;
 		KEEP(*(SORT(.binman_sym*)));
 		__binman_sym_end = .;
+		. = ALIGN(8);
 	} > .spl_mem
 
 	_end = .;
@@ -56,3 +57,6 @@ SECTIONS
 		__bss_end = .;
 	} > .bss_mem
 }
+
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");

arch/riscv/cpu/u-boot.lds

@@ -73,10 +73,9 @@ SECTIONS
 		__dyn_sym_start = .;
 		*(.dynsym)
 		__dyn_sym_end = .;
+		. = ALIGN(8);
 	}
 
-	. = ALIGN(8);
-
 	_end = .;
 
 	.bss : {
@@ -86,3 +85,5 @@ SECTIONS
 		__bss_end = .;
 	}
 }
+
+ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");

arch/sandbox/cpu/u-boot-spl.lds

@@ -25,9 +25,13 @@ SECTIONS
 		*(_u_boot_sandbox_getopt_start)
 		KEEP(*(_u_boot_sandbox_getopt))
 		*(_u_boot_sandbox_getopt_end)
+		. = ALIGN(8);
 	}
 
 	_image_binary_end = .;
 }
 
 INSERT AFTER .data;
+
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");

arch/x86/cpu/u-boot-64.lds

@@ -86,9 +86,11 @@ SECTIONS
 	__rel_dyn_end = .;
 	. = ALIGN(4);
 
-	.dynamic : { *(.dynamic) }
+	.dynamic : {
+		*(.dynamic)
+		. = ALIGN(8);
+	}
 
-	. = ALIGN(4);
 	_end = .;
 
 	.bss __rel_dyn_start (OVERLAY) : {

arch/x86/cpu/u-boot-spl.lds

@@ -68,7 +68,7 @@ SECTIONS
 		__bss_start = .;
 		*(.bss*)
 		*(COM*)
-		. = ALIGN(4);
+		. = ALIGN(8);
 		__bss_end = .;
 	}
 	__bss_size = __bss_end - __bss_start;
@@ -97,3 +97,11 @@ SECTIONS
 #endif
 
 }
+
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");
+
+#if !CONFIG_IS_ENABLED(SEPARATE_BSS)
+ASSERT(__bss_end % 8 == 0, \
+       "__bss_end must be 8-byte aligned for device tree");
+#endif

arch/x86/cpu/u-boot.lds

@@ -79,13 +79,12 @@ SECTIONS
 	. = ALIGN(4);
 	.dynsym : { *(.dynsym*) }
 
-	. = ALIGN(4);
-	__rel_dyn_start = .;
-	.rel.dyn : {
+	.rel.dyn ALIGN(4) : {
+		__rel_dyn_start = .;
 		*(.rel*)
+		__rel_dyn_end = .;
+		. = ALIGN(8);
 	}
-	__rel_dyn_end = .;
-	. = ALIGN(4);
 	_end = .;
 
 	.bss __rel_dyn_start (OVERLAY) : {
@@ -120,3 +119,5 @@ SECTIONS
 #endif
 
 }
+
+ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");

board/cssi/cmpc885/u-boot.lds

@@ -72,6 +72,7 @@ SECTIONS
 	 * _end - This is end of u-boot.bin image.
 	 * dtb will be appended here to make u-boot-dtb.bin
 	 */
+	. = ALIGN(8);
 	_end = .;
 
 	. = ALIGN(4096);
@@ -93,3 +94,5 @@ SECTIONS
 	PROVIDE (end = .);
 }
 ENTRY(_start)
+
+ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");

board/cssi/mcr3000/u-boot.lds

@@ -72,6 +72,7 @@ SECTIONS
 	 * _end - This is end of u-boot.bin image.
 	 * dtb will be appended here to make u-boot-dtb.bin
 	 */
+	. = ALIGN(8);
 	_end = .;
 
 	. = ALIGN(4096);
@@ -93,3 +94,5 @@ SECTIONS
 	PROVIDE (end = .);
 }
 ENTRY(_start)
+
+ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");

board/davinci/da8xxevm/u-boot-spl-da850evm.lds

@@ -43,6 +43,7 @@ SECTIONS
 		__rel_dyn_start = .;
 		*(.rel*)
 		__rel_dyn_end = .;
+		. = ALIGN(8);
 	} >.sram
 
 	__image_copy_end = .;
@@ -58,3 +59,6 @@ SECTIONS
 		__bss_end = .;
 	} >.sdram
 }
+
+ASSERT(_image_binary_end % 8 == 0, \
+       "_image_binary_end must be 8-byte aligned for device tree");

board/samsung/common/exynos-uboot-spl.lds

@@ -48,7 +48,10 @@ SECTIONS
 		. = ALIGN(4);
 		__bss_start = .;
 		*(.bss*)
-		. = ALIGN(4);
+		. = ALIGN(8);
 		__bss_end = .;
 	} >.sram
 }
+
+ASSERT(__bss_end % 8 == 0, \
+       "__bss_end must be 8-byte aligned for device tree");