[U-Boot] Help: CONFIG_ENV_IS_IN_SPI_FLASH on AllWinner H5?

[g4 at novadsp.com]

Greetings. Please let me know if there is a better place to ask this
question.

Any clues here? I've got an AllWinner H5 with Winbond SPI flash attached on
SPI0. The flash is programmed using the sunxi FEL tools and boots perfectly.
Now I'd like to save the environment there too. 

Loading Environment from SPI Flash... 
Invalid bus 0 (err=-19)
*** Warning - spi_flash_probe_bus_cs() failed, using default environment

TAIA

Jerry.
-------------------------------------------------------
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_CMD_SF=y
CONFIG_CMD_SF_TEST=y
CONFIG_DEFAULT_DEVICE_TREE="anemos-sc5"
CONFIG_ENV_IS_IN_SPI_FLASH=y
CONFIG_NET_RANDOM_ETHADDR=y
CONFIG_MTD=y
CONFIG_MTD_DEVICE=y
CONFIG_DM_SPI_FLASH=y
CONFIG_SUN8I_EMAC=y
CONFIG_SPI=y
CONFIG_DM_SPI=y
CONFIG_SUN4I_SPI=y
CONFIG_SOFT_SPI=y
CONFIG_USB_EHCI_HCD=y
CONFIG_SYS_USB_EVENT_POLL_VIA_INT_QUEUE=y
CONFIG_USB_HOST_ETHER=y
...

------------------------------------------------
Device tree looks sane but I am no judge.

-------------------------------------------------------
=> fdt list /soc/spi at 1c68000
spi at 1c68000 {
        compatible = "allwinner,sun8i-h3-spi";
        reg = <0x01c68000 0x00001000>;
        interrupts = <0x00000000 0x00000041 0x00000004>;
        clocks = <0x00000003 0x0000001e 0x00000003 0x00000052>;
        clock-names = "ahb", "mod";
        dmas = <0x00000014 0x00000017 0x00000014 0x00000017>;
        dma-names = "rx", "tx";
        pinctrl-names = "default";
        pinctrl-0 = <0x00000015>;
        resets = <0x00000003 0x0000000f>;
        status = "okay";
        #address-cells = <0x00000001>;
        #size-cells = <0x00000000>;
        spi_flash at 0 {
        };

-------------------------------------------------------
=> fdt list /soc/spi at 1c68000/spi_flash at 0
spi_flash at 0 {
        compatible = "spi-flash";
        reg = <0x00000000>;
        spi-max-frequency = <0x02faf080>;
        u-boot,dm-pre-reloc;
};