[U-Boot] [U-Boot, v5, 5/8] omap-common: SYS_BOOT-based fallback boot device selection for peripheral boot
Paul Kocialkowski
contact at paulk.fr
Tue Aug 25 16:44:20 CEST 2015
> > If I got everything right, the bootrom is passing BOOT_DEVICE_UART as
> > boot device, but you haven't selected CONFIG_SPL_YMODEM_SUPPORT. Thus,
> > it falls back to asking omap_sys_boot_device, which is not implemented.
> I don't think, there is everything right. Have a closer look to the #ifdef.
>
> #if (defined(BOOT_DEVICE_UART) && !defined(CONFIG_SPL_YMODEM_SUPPORT)) || \
> (defined(BOOT_DEVICE_USB) && !defined(CONFIG_SPL_USB_SUPPORT)) || \
> (defined(BOOT_DEVICE_USBETH) && !defined(CONFIG_SPL_USBETH_SUPPORT))
>
> I have enabled CONFIG_SPL_YMODEM_SUPPORT, look at bur_am335x_common.h.
>
> > The real problem here is that you have not enabled support for loading
> > the main U-Boot binary via UART, with CONFIG_SPL_YMODEM_SUPPORT.
> >
> > UART booting is unrelated to CONFIG_SPL_USBETH_SUPPORT.
> No, due to the fact that defined(BOOT_DEVICE_USBETH) is allways true
> (spl.h) and i don't have
> CONFIG_SPL_USBETH_SUPPORT enabled, the #ifdef above:
>
> defined(BOOT_DEVICE_USBETH) && !defined(CONFIG_SPL_USBETH_SUPPORT)
>
> becomes true and the followed switch/case does the rest.
Oh you're right, I hadn't thought this through.
I'll think about how to solve this in the cleanest way (I wouldn't want
to duplicate the ifdef logic too much). Thanks for bringing this up.
> >> further i think that this construct isn't complete yet, because it
> >> wants to handle all peripheral booting on AM335x or OMAP in general.
> >>
> >> following peripherals are currently handled:
> >>
> >> BOOT_DEVICE_UART
> >> BOOT_DEVICE_USB
> >> BOOT_DEVICE_USBETH
> >>
> >> but there is also
> >> BOOT_DEVICE_CPGMAC
> >>
> >> Summary i think this changeset isn't complete.
> > Can the bootrom indicate that it booted from BOOT_DEVICE_CPGMAC?
> > I haven't seen that and don't really know what it corresponds to. But if
> > you think it is concerned by this fallback mechanism, you could add
> > support for it. I only made this for the omap devices I have (and I
> > don't have any am33xx board) and I didn't want to blindly implement too
> > much for am33xx.
> Yes, thats possible von AM335x.
> I will have a close look if it is necessary to implement here some fallback.
> But probably not, because the most likely case is that "full" U-Boot
> supports Ethernet and the SPL doesn't and not otherwise :-)
Alright then, that's fine with me. It's okay if the fallback mechanism
doesn't handle all use cases, too.
--
Paul Kocialkowski, Replicant developer
Replicant is a fully free Android distribution running on several
devices, a free software mobile operating system putting the emphasis on
freedom and privacy/security.
Website: http://www.replicant.us/
Blog: http://blog.replicant.us/
Wiki/tracker/forums: http://redmine.replicant.us/
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