sunxi: Normalise FEL support

[karo-tx-uboot.git] / board / sunxi / Kconfig

diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig
index 4a2158988fc9bce0d1991d51e72586e7c2af5615..3eab81fd12b17fc530595258cbecd2b91d926816 100644 (file)
--- a/board/sunxi/Kconfig
+++ b/board/sunxi/Kconfig
@@ -149,6 +149,16 @@ config SPL_FEL
        bool "SPL/FEL mode support"
        depends on SPL
        default n
+       help
+         This enables support for Fast Early Loader (FEL) mode. This
+         allows U-Boot to be loaded to the board over USB by the on-chip
+         boot rom. U-Boot should be sent in two parts: SPL first, with
+         'fel write 0x2000 u-boot-spl.bin; fel exe 0x2000' then U-Boot with
+         'fel write 0x4a000000 u-boot.bin; fel exe 0x4a000000'. This option
+         shrinks the amount of SRAM available to SPL, so only enable it if
+         you need FEL. Note that enabling this option only allows FEL to be
+         used; it is still possible to boot U-Boot from boot media. U-Boot
+         SPL detects when it is being loaded using FEL.
 
 config UART0_PORT_F
        bool "UART0 on MicroSD breakout board"