Re: [PATCH 02/10] arm: Update linker scripts to ensure appended device tree is aligned

[Phil Sutter <phil@nwl.cc>]

On Wed, Feb 04, 2026 at 03:31:39PM -0600, Tom Rini wrote:
> On Wed, Feb 04, 2026 at 10:27:11PM +0100, Phil Sutter wrote:
> > On Wed, Feb 04, 2026 at 03:20:10PM -0600, Tom Rini wrote:
> > > On Wed, Feb 04, 2026 at 10:16:12PM +0100, Phil Sutter wrote:
> > > > Hi,
> > > > 
> > > > On Thu, Jan 15, 2026 at 04:19:32PM -0600, Tom Rini wrote:
> > > > > 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 f613a6e15ef7 ("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:
> > > > > - Expands some linker sections 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.
> > > > > - Ensure that we do have alignment by adding an ASSERT so that when not
> > > > >   aligned we fail to link (and explain why).
> > > > > - Remove now-spurious  '. = ALIGN(x);' statements that were intended to
> > > > >   provide the above alignments.
> > > > > 
> > > > > Signed-off-by: Tom Rini <trini@konsulko.com>
> > > > 
> > > > For unclear reasons, this seems to break boot via xmodem protocol on my
> > > > Synology DS414. I found this commit via 'git bisect'. The symptom is:
> > > > 
> > > > | kwboot version 2026.04-rc1-00098-g6ad0cf8f83db
> > > > | Detected kwbimage v1 with SPI boot signature
> > > > | Patching image boot signature to UART
> > > > | Aligning image header to Xmodem block size
> > > > | Sending boot message. Please reboot the target...\
> > > > | Sending boot image header (67584 bytes)...
> > > > |   0 % [......................................................................]
> > > > |  13 % [......................................................................]
> > > > |  26 % [......................................................................]
> > > > |  39 % [......................................................................]
> > > > |  53 % [......................................................................]
> > > > |  66 % [......................................................................]
> > > > |  79 % [......................................................................]
> > > > |  92 % [......................................                                ]
> > > > | Done
> > > > | Missing DTB
> > > > | spl_init() failed: -2
> > > > | ### ERROR ### Please RESET the board ###
> > > > | 
> > > > | 
> > > > | xmodem: Connection timed out
> > > > 
> > > > Debug printf()s in fdtdec_prepare_fdt() show that fdt_check_header()
> > > > returns -FDT_ERR_BADMAGIC.
> > > > 
> > > > With HEAD at a8d982e1f1726 ("x86: cpu: Fix crash on FTRACE enabled
> > > > builds"), reverting arch/arm/cpu/u-boot-spl.lds like so:
> > > > 
> > > > | @@ -41,14 +41,21 @@ SECTIONS
> > > > |                 __binman_sym_start = .;
> > > > |                 KEEP(*(SORT(.binman_sym*)));
> > > > |                 __binman_sym_end = .;
> > > > | -               . = ALIGN(8);
> > > > |         }
> > > > |  
> > > > | +       . = ALIGN(4); /* critical! */
> > > > |         __image_copy_end = .;
> > > > | +       .rel.dyn : {
> > > > | +               __rel_dyn_start = .;
> > > > | +               *(.rel*)
> > > > | +               __rel_dyn_end = .;
> > > > | +       }
> > > > | +
> > > > | +       . = ALIGN(8);
> > > > |         _image_binary_end = .;
> > > > |         _end = .;
> > > > |  
> > > > | -       .bss : {
> > > > | +       .bss __rel_dyn_start (OVERLAY) : {
> > > > |                 __bss_start = .;
> > > > |                 *(.bss*)
> > > > |                  . = ALIGN(8);
> > > > 
> > > > The SPL image starts up again and continues loading the real uboot
> > > > image. Note that I have no idea what these changes actually do, so I
> > > > need instructions if I should dig further.
> > > 
> > > Does:
> > > https://patchwork.ozlabs.org/project/uboot/patch/20260130183635.2612933-1-trini@konsulko.com/
> > > fix it?
> > 
> > Sadly not, same result.
> 
> Ugh. What file, specifically, do you send via xmodem? And so that maybe
> I can more easily replicate the failure, are you using the kernel.org
> gcc-14.2.0 toolchain or something else?

I am building with a custom-built arm-openadk-linux-uclibceabi-gcc
version 14.3.0. Basically what I run is:

MYENV='ARCH=arm CROSS_COMPILE=~/git/openadk-ds414/toolchain_synology-ds414_uclibc-ng_softfp_eabi_arm/usr/bin/arm-openadk-linux-uclibceabi-'

make $MYENV clean && \
for f in $(ls u-boot*.kwb 2>/dev/null); do rm $f; done && \
make $MYENV ds414_defconfig && \
make $MYENV -j12 && \
./tools/kwboot -a -t -p -b u-boot-*spl.kwb /dev/ttyUSB0

With current uboot, this should be u-boot-with-spl.kwb image.

With said patch reverted (or the above changes applied), I produce a
working u-boot-with-spl.kwb which loads and boots linux from flash. So
my toolchain is at least not totally broken. ;)

Cheers, Phil