+# SPDX-License-Identifier: GPL-2.0+
#
# Copyright (C) 2015 Google. Inc
# Written by Simon Glass <sjg@chromium.org>
-#
-# SPDX-License-Identifier: GPL-2.0+
-#
U-Boot on Rockchip
==================
=>
The rockchip bootrom can load and boot an initial spl, then continue to
-load a second-level bootloader(ie. U-BOOT) as soon as it returns to bootrom.
-Therefore RK3288 has another loading sequence like RK3036. The option of
-U-Boot is controlled with this setting in U-Boot:
+load a second-stage bootloader (ie. U-Boot) as soon as the control is returned
+to the bootrom. Both the RK3288 and the RK3036 use this special boot sequence.
+The configuration option enabling this is:
- #define CONFIG_SPL_ROCKCHIP_BACK_TO_BROM
+ CONFIG_SPL_ROCKCHIP_BACK_TO_BROM=y
You can create the image via the following operations:
The bootrom of rk3188 expects to find a small 1kb loader which returns
control to the bootrom, after which it will load the real loader, which
-can then be up to 29kb in size and does the regular ddr init.
+can then be up to 29kb in size and does the regular ddr init. This is
+handled by a single image (built as the SPL stage) that tests whether
+it is handled for the first or second time via code executed from the
+boot0-hook.
Additionally the rk3188 requires everything the bootrom loads to be
rc4-encrypted. Except for the very first stage the bootrom always reads
and decodes 2kb pages, so files should be sized accordingly.
# copy tpl, pad to 1020 bytes and append spl
-cat tpl/u-boot-tpl.bin > tplspl.bin
-truncate -s 1020 tplspl.bin
-cat spl/u-boot-spl.bin >> tplspl.bin
-tools/mkimage -n rk3188 -T rksd -d tplspl.bin out
+tools/mkimage -n rk3188 -T rksd -d spl/u-boot-spl.bin out
# truncate, encode and append u-boot.bin
truncate -s %2048 u-boot.bin