In past SPL_ZYNQMP_TWO_SDHCI symbol was introduced to handle boards with
two sdhci controllers. The problem was that U-Boot is registering
controllers based on aliases in DT but bootmode targets specific controller
ID. That's why on boards with one "second" sdhci controller bootmode was
pointing to second controller(MMC2) but alias was setup to mmc0 (the first
controller). And SPL requires to point to mmc0 in this case.
Long time ago commit
f101e4bd3703
("spl: add support for alternative boot device") added support for handling
multiple bootmodes in SPL. Use this functionality and setup second sdhci
controller as backup boot device.
Below is table with behavior:
HW/bootmode bootorder
sd0/sd0 mmc0/mmc1 (mmc1 never called)
sd1/sd1 mmc1/mmc0 (mmc0 fails and mmc1 is called)
sd0+sd1/sd0 mmc0/mmc1 (mmc1 never called)
sd0+sd1/sd1 mmc1/mmc0 (mmc0 never called)
All other bootmodes are not affected but order can be extended to cover
advance boot flows.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>