[U-Boot] Sunxi H5 and CONFIG_ENV_IS_IN_MMC problem

[g4 at novadsp.com]

Greetings

Our board has an AllWinner H5 with SPI flash and eMMC. Since SPI flash
support for 'saveenv' is not currently mainline, I thought I'd simply use
one of the eMMC boot blocks to persist the environment. However I keep
running into image size problems [1]

Not being a U-Boot ninja, the defconfig [2] is about as minimal as I believe
I can make it. (Network support is required for TFTP/NFS operations) Does
the panel have any suggestions for getting the desired configuration built?

MTIA.

Jerry.
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[1]
MKSUNXI spl/sunxi-spl.bin
  MKIMAGE u-boot.img
  MKIMAGE u-boot-dtb.img
/home/moi/src/u-boot/denx/"board/sunxi/mksunxi_fit_atf.sh" \
arch/arm/dts/anemos-sc5.dtb > u-boot.its
  MKIMAGE u-boot.itb
u-boot.itb exceeds file size limit:
  limit:  516096 bytes
  actual: 519448 bytes
  excess: 3352 bytes
/home/moi/src/u-boot/denx/Makefile:1204: recipe for target 'u-boot.itb'
failed

----------------------------snip------------------------------------------
[2]
CONFIG_ARM=y
CONFIG_ARCH_SUNXI=y
CONFIG_SPL=y
CONFIG_MACH_SUN50I_H5=y
CONFIG_DRAM_CLK=504
CONFIG_DRAM_ZQ=3881977
CONFIG_DRAM_ODT_EN=y
CONFIG_MACPWR="PD6"
CONFIG_MMC_SUNXI_SLOT_EXTRA=2
CONFIG_SPL_SPI_SUNXI=y
CONFIG_SPL_SPI_FLASH_SUPPORT=y
CONFIG_SPL_SPI_FLASH_TINY=y
CONFIG_DEFAULT_DEVICE_TREE="anemos-sc5"
CONFIG_ENV_IS_IN_MMC=y
CONFIG_NET_RANDOM_ETHADDR=y
CONFIG_MTD=y
CONFIG_MTD_DEVICE=y
CONFIG_SUN8I_EMAC=y
CONFIG_USB_EHCI_HCD=y
CONFIG_SYS_USB_EVENT_POLL_VIA_INT_QUEUE=y