From 410d31bae4b863eabd70adb22a0c9976bfe4fee3 Mon Sep 17 00:00:00 2001 From: Tom Rini Date: Thu, 15 Jan 2026 16:19:40 -0600 Subject: x86: Update linker scripts to ensure appended device tree is aligned With commit 0535e46d55d7 ("scripts/dtc: Update to upstream version v1.7.2-35-g52f07dcca47c") it is now a fatal error to U-Boot if our device tree is not 8-byte aligned. In commit 85f586035d75 ("ARM: OMAP2+: Pad SPL binary to 8-byte alignment before DTB") Beleswar Padhi explains that we must have ALIGN(x) statements inside of a section to ensure that padding is included and not simply that the linker address counter is incremented. To that end, this patch: - Rewrite the '.rel.dyn' (u-boot.lds) to follow modern practices, and include the 8-byte alignment at the end of the section. - Expands the '.dynamic' section (u-boot-64.lds) to be more readable when adding a second statement to the section. - Aligns the final section before _end (for U-Boot) or _image_binary_end or __bss_end (for xPL phases) by 8-bytes by adding '. = ALIGN(8);' to the final section before the symbol or changing an existing ALIGN(4) statement. - Ensure that we do have alignment by adding an ASSERT so that when not aligned we fail to link (and explain why). Signed-off-by: Tom Rini --- arch/x86/cpu/u-boot-64.lds | 6 ++++-- arch/x86/cpu/u-boot-spl.lds | 10 +++++++++- arch/x86/cpu/u-boot.lds | 11 ++++++----- 3 files changed, 19 insertions(+), 8 deletions(-) diff --git a/arch/x86/cpu/u-boot-64.lds b/arch/x86/cpu/u-boot-64.lds index 00a6d869121..0c353c5d740 100644 --- a/arch/x86/cpu/u-boot-64.lds +++ b/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) : { diff --git a/arch/x86/cpu/u-boot-spl.lds b/arch/x86/cpu/u-boot-spl.lds index 50b4b160855..57cdce6d751 100644 --- a/arch/x86/cpu/u-boot-spl.lds +++ b/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 diff --git a/arch/x86/cpu/u-boot.lds b/arch/x86/cpu/u-boot.lds index c418ff44aa0..ea070acd6a1 100644 --- a/arch/x86/cpu/u-boot.lds +++ b/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"); -- cgit v1.3.1