Booting from SPI-NAND

[Thomas Marangoni]

Hello,
I have an Allwinner suniv f1c100s and trying to boot the device from SPI-NAND. Booting from SD-Cards works without problems.

I'm using "sunxi-next" branch from "sunxi U-Boot Custodian Tree". The SPI-NAND device is detected with "mtd list", but when flashing u-boot with spl to the SPI-NAND, the device doesn't boot. Not even the SPL Boot Message is showing up.
I attached the output of "mtd list" and the config at the end of this message. Can someone give me a hint?

List of MTD devices:
* spi-nand0
  - device: w25n512 at 0
  - parent: spi at 1c05000
  - driver: spi_nand
  - path: /soc/spi at 1c05000/w25n512 at 0
  - type: NAND flash
  - block size: 0x20000 bytes
  - min I/O: 0x800 bytes
  - OOB size: 64 bytes
  - OOB available: 24 bytes
  - 0x000000000000-0x000008000000 : "spi-nand0"
          - 0x000000000000-0x000000080000 : "u-boot"
          - 0x000000080000-0x000004000000 : "linux"

config:
CONFIG_ARM=y
CONFIG_SKIP_LOWLEVEL_INIT_ONLY=y
CONFIG_SPL_SKIP_LOWLEVEL_INIT_ONLY=y
CONFIG_SYS_DCACHE_OFF=y
CONFIG_ARCH_SUNXI=y
CONFIG_ENV_SIZE=0x8000
CONFIG_ENV_OFFSET=0xf8000
CONFIG_ENV_SECT_SIZE=0x800
CONFIG_DEFAULT_DEVICE_TREE="suniv-f1c100s-mc4l"
CONFIG_SPL=y
CONFIG_MACH_SUNIV=y
CONFIG_DRAM_CLK=156
CONFIG_DRAM_ZQ=0
# CONFIG_VIDEO_SUNXI is not set
CONFIG_SPL_SPI_SUNXI=y
CONFIG_SD_BOOT=y
CONFIG_SPI_BOOT=y
CONFIG_LOG=y
CONFIG_LOG_MAX_LEVEL=7
CONFIG_SPL_SHOW_ERRORS=y
CONFIG_SHOW_ERRORS=y
CONFIG_SPL_MTD_SUPPORT=y
# CONFIG_BOOTM_NETBSD is not set
# CONFIG_BOOTM_PLAN9 is not set
# CONFIG_BOOTM_RTEMS is not set
# CONFIG_BOOTM_VXWORKS is not set
CONFIG_CMD_CLK=y
CONFIG_CMD_MTD=y
# CONFIG_CMD_SF is not set
CONFIG_CMD_SPI=y
CONFIG_CMD_MTDPARTS=y
CONFIG_CMD_UBI=y
# CONFIG_NET is not set
CONFIG_DM=y
CONFIG_MTD=y
CONFIG_DM_MTD=y
CONFIG_MTD_SPI_NAND=y
CONFIG_SPI_FLASH_BAR=y
CONFIG_SPI_FLASH_WINBOND=y
CONFIG_SPI_FLASH_MTD=y
CONFIG_SPI=y