[PATCH v2] xyz-modem: Select CRC16

[Tom Rini]

On Mon, Jun 08, 2026 at 03:59:11PM +0200, Quentin Schulz wrote:
> Hi Daniel,
> 
> On 6/8/26 3:06 PM, Daniel Palmer wrote:
> > - CONFIG_LOADB causes the xyzModem code to get built and that code depends
> >    on CONFIG_CRC16. If you don't have something else that selects CONFIG_CRC16
> >    you can unselect it and then the final link will fail:
> > 
> >    LD      u-boot
> > /usr/bin/m68k-linux-gnu-ld.bfd: common/xyzModem.o: in function `xyzModem_get_hdr':
> > u-boot/common/xyzModem.c:388:(.text.xyzModem_get_hdr+0x17a): undefined reference to `crc16_ccitt'
> > 
> > - Add CONFIG_YMODEM_SUPPORT, make that select CONFIG_CRC16 and make
> >    CONFIG_LOADB select CONFIG_YMODEM_SUPPORT.
> > 
> > - SPL/TPL already have Kconfig symbols for ymodem support but the spl
> >    ymodem code has issues building in the TPL phase and doesn't seem to
> >    be used:
> > 
> > /usr/bin/aarch64-linux-gnu-ld.bfd: common/spl/spl_ymodem.o: in function `spl_ymodem_load_image':
> > u-boot/common/spl/spl_ymodem.c:138:(.text.spl_ymodem_load_image+0xdc): undefined reference to `spl_load_simple_fit'
> > u-boot/common/spl/spl_ymodem.c:138:(.text.spl_ymodem_load_image+0xdc): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `spl_load_simple_fit'
> > make[1]: *** [scripts/Makefile.xpl:546: tpl/u-boot-tpl] Error 1
> > 
> > - Remove the ymodem symbol entirely for TPL.
> > 
> > - Select CONFIG_SPL_CRC16 for SPL.
> > 
> > - Finally, since everyone is now using the ymodem support symbols remove
> >    the special rule for loadb in the makefile.
> > 
> 
> When you need to list what you're doing in a commit log, it usually means
> you should be splitting the content into multiple separate patches (in a
> single series is usually fine/recommended).
> 
> What I could identify (slightly reworked, which better match how *I* would
> write the patches):
> 
> - changes made to common/spl/Kconfig.tpl with the justification given above,
> - adding the missing CRC16 dependency to CMD_LOADB,
> - adding missing SPL_CRC16 dependency to SPL_YMODEM_SUPPORT (possibly
> squashed with the CMD_LOADB+CRC16 patch above, I'm undecided on what's best
> here),
> - create new YMODEM_SUPPORT symbol and migrate CMD_LOADB + common/Makefile
> to use that,
> 
> This makes it clearer what the purpose of each individual commit is:
> - remove dead code
> - fix existing support for CMD_LOADB,
> - fix existing support for SPL_YMODEM_SUPPORT,
> - quality of life improvement by migrating the CRC16 dependency from
> CMD_LOADB into a new symbol + making use of that new symbol in
> common/Makefile instead of "hardlinking" CMD_LOADB with building xyzModem.o
> (which is quite honestly confusing, so good to see this fixed!),
> 
> What do you think?
> 
> > Signed-off-by: Daniel Palmer <daniel at thingy.jp>
> > ---
> > 
> > v2: Fix the SPL/TPL stuff as brought up by Tom. This opened a can of
> >      worms when I tested if the TPL builds or not so I decided to just
> >      remove the TPL ymodem stuff. It didn't seem to be used in any
> >      defconfig and there isn't a CONFIG_TPL_CRC16 to enable the needed
> >      crc16 code anyhow so maybe it hasn't been used for a while?
> > 
> >   cmd/Kconfig            |  1 +
> >   common/Kconfig         |  4 ++++
> >   common/Makefile        |  1 -
> >   common/spl/Kconfig     |  1 +
> >   common/spl/Kconfig.tpl | 11 +----------
> >   5 files changed, 7 insertions(+), 11 deletions(-)
> > 
> > diff --git a/cmd/Kconfig b/cmd/Kconfig
> > index c71c6824a196..503fc51f6bb4 100644
> > --- a/cmd/Kconfig
> > +++ b/cmd/Kconfig
> > @@ -1412,6 +1412,7 @@ config CMD_W1
> >   config CMD_LOADB
> >   	bool "loadb"
> >   	default y
> > +	select YMODEM_SUPPORT
> >   	help
> >   	  Load a binary file over serial line.
> > diff --git a/common/Kconfig b/common/Kconfig
> > index 8e8c733aa295..0db74aa580e4 100644
> > --- a/common/Kconfig
> > +++ b/common/Kconfig
> > @@ -1274,3 +1274,7 @@ config IO_TRACE
> >   	  confirm that the driver behaves the same way before and after a code
> >   	  change. To add support for your architecture, add '#include
> >   	  <iotrace.h>' to the bottom of arch/<arch>/include/asm/io.h and test.
> > +
> > +config YMODEM_SUPPORT
> > +	bool
> > +	select CRC16
> 
> Is there any reason we wouldn't want the user to be able to select this
> independently from CMD_LOADB?
> 
> I'm asking because this is both invisible (no prompt) and has no help text.

I think this should stay hidden as it's *not* hidden for xPL as it's the
equivalent of CMD_LOADB but it's the symbol for the library portion. As
a maybe clearer result, maybe the library symbol should be
XYZMODEM_SUPPORT / xPL_XYZMODEM_SUPPORT, to control building
common/xyzModem.o ?

-- 
Tom
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