[U-Boot] [PATCH v2 0/3] sunxi: support FEL-provided environment vars and "fel" boot target

[Bernhard Nortmann]

This patch series builds upon
http://lists.denx.de/pipermail/u-boot/2015-September/226515.html
http://lists.denx.de/pipermail/u-boot/2015-September/226688.html

v2 combines the previous submissions, and adds some suggested
fixes/changes.

The sunxi-tool side of things is discussed here:
https://www.mail-archive.com/linux-sunxi@googlegroups.com/msg13071.html

* Hans de Goede already pointed out that it might be preferable to
make use of the spl_boot_device() function even from the main
(non-SPL) U-Boot binary (e.g. for the "NAND" case). Currently this
function is only available with CONFIG_SPL_BUILD set, and
implemented in arch/arm/cpu/armv7/sunxi/board.c
Would it be safe to enable it for non-SPL builds and use something
like "(spl_boot_device == BOOT_DEVICE_BOARD)" for misc_init_r()?

* Side note: the sunxi spl_boot_device() will probably require
some future refinement anyway, to account for the 'oddball' A80.
That SoC requires the SPL at a different address (0x10000 instead
of 0x0).

* The test for FEL boot mode ("eGON.BT0") in spl_boot_device()
explicitly uses the "io" function readl() to access the signature.
Is there a specific reason for this? Marex pointed out (on IRC)
that the SRAM might as well be read directly. For now, I have
followed the existing code, and used readl() and readb() to work
with the SPL header information.

* The check_signature() function somewhat duplicates very similar
code from arch/arm/include/asm/io.h. That particular piece of code
depends on the presence of a "__mem_pci" symbol. However, it seems
'generic' enough - so it may be worth to factor out and reuse it?

Regards, B. Nortmann

Changes in v2:
- Rename field to fel_script_address, discard fel_data_size
- Clearing header fields is no longer needed, as mksunxiboot.c zeroes entire image first
- renamed fel_data_addr to fel_script_addr, discarded fel_data_size
- make sure that FEL-related environment vars are always cleared first
- support minimum and maximum SPL (header) version, more verbose error messages
- renamed fel_data_addr to fel_scriptaddr
- combined both tests into one as suggested by Hans de Goede

Bernhard Nortmann (3):
  sunxi: (mksunxiboot) signature to indicate "sunxi" SPL variant
  sunxi: retrieve FEL-provided values to environment variables
  sunxi: add "fel" boot target

 board/sunxi/board.c            | 56 ++++++++++++++++++++++++++++++++++++++++++
 include/configs/sunxi-common.h | 11 +++++++++
 tools/mksunxiboot.c            | 23 ++++++++++++++++-
 3 files changed, 89 insertions(+), 1 deletion(-)

-- 
2.4.6