[U-Boot] [linux-sunxi] [PATCH v4 00/26] sunxi: Allwinner A64: SPL support
jonsmirl at gmail.com
jonsmirl at gmail.com
Tue Jan 3 03:38:44 CET 2017
I recently ran into a probably with the UARTs on the A64. Many
Bluetooth modules (like Ampak) use the UART. The data rate of EDR BT
is 3Mb/s with about 2.1Mb/s though put. To handle this most systems
set the speed of the BT UART to 3Mb/s.
By default the Allwinner UART clock input is OSC24. When using OSC24
the maximum speed the UART can be set to is 1.5Mb/s. The clock input
(apb2) can be changed over to PERIPH0x2 (1.2ghz) via the device tree
and 3Mb/s is then supported.
But... there's a problem, UART0 (the console) is using the same master
clock source. So when you change the clock input over to PERIPH0x2 the
console stops working. There is no mechanism in Linux to handle this
clock source change and adjust the dividers on active uarts. So it
would be best if this master clock was set very early in u-boot and
then the console is adjusted to use it.
Are there any downsides to making this change in u-boot?
On Mon, Jan 2, 2017 at 6:48 AM, Andre Przywara <andre.przywara at arm.com> wrote:
> Hi,
>
> hopefully the final version of the SPL support series for the Allwinner A64
> SoC. Actually no real code changes this time, just rebased on top of recent
> master, adding some comments in patches 16/26 and 19/26 following Maxime's
> suggestions and adding Acked-by:s and Reviewed-by:s.
> I left the final patch 26/26 in for the sake of completeness, but don't expect
> it to be merged. We need a clever solution to unify 32-bit and 64-bit board
> configurations, but that shouldn't hold back this series for now.
> Merging everything until and including patch 21/26 (sunxi: A64: enable SPL)
> would be great, the other patches until 25/26 can go in as well, I think.
>
> -------------
> As the previous versions this one includes support for both AArch64 and
> AArch32 SPL builds. The FIT support is still missing, which means the
> functionality is limited. Due to the missing ARM Trusted Firmware (ATF)
> in this firmware chain we lose Ethernet and SMP, among other minor things.
> A full 64-bit build can be written to an SD card as expected and will
> boot the U-Boot proper prompt. However Linux will crash on boot, as
> PSCI is missing.
> Building the 32-bit version of the SPL and combining this with an ATF
> build and the 64-bit U-Boot proper allows to use FEL booting now:
> # sunxi-fel spl sunxi-spl.bin write 0x4a000000 u-boot-dtb.bin \
> write 0x44000 bl31.bin reset64 0x44000
> This way of booting the board gives full functionality.
>
> The first patch is a rather simple fix (with no changes to v2).
> Patches 2-8 prepare the SPL code to be compiled for 64-bit in general and
> AArch64 in particular.
> Patches 9-11 refactor the existing boot0 header functionality to be used
> by patch 12, which introduces the 64-bit switch in the first SPL
> instructions.
> Patches 13-20 then introduce the actual core of the SPL support: the DRAM
> initialization, courtesy of Jens. This piggy backs on the existing
> H3 DRAM code, deviating where needed. This has been reworked compared to
> v2: I added a patch from Philipp to replace the rather uninspired
> register writes in the MBUS priority setup function with some meaningful
> code, explaining the various bits. Also the actual A64 DRAM code is no
> longer #ifdef'ed into the H3 driver, but uses parameters to (static)
> functions. The compiler detects this and removes the dead code from
> the other variant, resulting in the same binary size for the H3.
>
> Patch 21 finally enables the 64-bit SPL support. So now building the
> existing pine64_plus_defconfig will generate a sunxi-spl.bin, which
> can be prepended to the U-Boot proper image (not .bin) to boot from
> an SD card. Due to the missing ATF support this is of limited usability
> at the moment, though. Also FEL support requires more love - to switch
> back to AArch32 before returning to FEL (without crashing, that is ;-),
> so this is disabled.
> On my setup this results in a 26KB SPL binary, which is close to the
> 28K limit mksunxiboot imposes at the moment. Adding anything (like
> FIT support or DEBUG) will exceed this, and although I have patches
> to let mksunxiboot get close to 32KB, this is the ulimate frontier.
>
> So patches 22-25 then teach the SPL how to detect an U-Boot image file
> of a different bitness and do the RMR switch from AArch32 to AArch64,
> if needed.
> This is used by the final patch 26, which creates another _defconfig
> to let the SPL compile for AArch32 using the Thumb2 encoding. This
> results in a binary of less than 17KB in my case, so has plenty of
> room for extensions.
>
> Cheers,
> Andre.
>
> Changelog v3 .. v4:
> - rebased on top of latest HEAD
> - add various Reviewed-by: and Acked-by: tags
> - add comments about register bit meanings in non-ODT-setting fix
> - clarify meaning of delay values in single bit delay support patch
> - removing stray semicolons from boot0.h header
>
> Changelog v2 .. v3:
> - add various Reviewed-by: and Acked-by: tags
> - split tiny-printf fix to handle "-" separately
> - add various comments and extend commit messages
> - add assembly file to re-create the embedded RMR switch code
> - add patch 14/26 to explain the MBUS priority setup
> - move DRAM r/w delay values into #defines to simplify re-usablity
> - replace #ifdef'ed addition of A64 support to the H3 DRAM driver with an
> approach using static parameters
>
> Changelog v1 .. v2:
> - drop SPI build fix (already merged)
> - confine A31 register init change to H3 and A64
> - use IS_ENABLED() instead of #idef to guard MBUS2 clock init
> - fix tiny-printf (proper sign extension for 32-bit integers)
> - add "size" output in commit msg to document tiny-printf size impact
> - fix sdelay(): use only one register, add "cc" clobber
> - update RMR switch code to provide easy access to RVBAR register address
> - drop redundant DRAM frequency setting from Pine64 defconfig
> - minor changes as requested by reviewers
>
> Andre Przywara (21):
> sun6i: Restrict some register initialization to Allwinner A31 SoC
> armv8: prevent using THUMB
> armv8: add lowlevel_init.S
> SPL: tiny-printf: add "l" modifier
> SPL: tiny-printf: ignore "-" modifier
> move UL() macro from armv8/mmu.h into common.h
> SPL: make struct spl_image 64-bit safe
> armv8: add simple sdelay implementation
> armv8: move reset branch into boot hook
> ARM: boot0 hook: remove macro, include whole header file
> sunxi: introduce extra config option for boot0 header
> sunxi: A64: do an RMR switch if started in AArch32 mode
> sunxi: provide default DRAM config for sun50i in Kconfig
> sunxi: H3/A64: fix non-ODT setting
> sunxi: DRAM: fix H3 DRAM size display on aarch64
> sunxi: A64: enable SPL
> SPL: read and store arch property from U-Boot image
> Makefile: use "arm64" architecture for U-Boot image files
> ARM: SPL/FIT: differentiate between arm and arm64 arch properties
> sunxi: introduce RMR switch to enter payloads in 64-bit mode
> sunxi: A64: add 32-bit SPL support
>
> Jens Kuske (3):
> sunxi: H3: add and rename some DRAM contoller registers
> sunxi: H3: add DRAM controller single bit delay support
> sunxi: A64: use H3 DRAM initialization code for A64 as well
>
> Philipp Tomsich (2):
> sunxi: H3: Rework MBUS priority setup
> sunxi: clocks: Use the correct pattern register for PLL11
>
> Makefile | 9 +-
> arch/arm/cpu/armv8/Makefile | 1 +
> arch/arm/cpu/armv8/cpu.c | 14 +
> arch/arm/cpu/armv8/lowlevel_init.S | 44 +++
> arch/arm/cpu/armv8/start.S | 5 +-
> arch/arm/include/asm/arch-bcm235xx/boot0.h | 8 +-
> arch/arm/include/asm/arch-bcm281xx/boot0.h | 8 +-
> arch/arm/include/asm/arch-sunxi/boot0.h | 37 ++-
> arch/arm/include/asm/arch-sunxi/clock_sun6i.h | 1 +
> arch/arm/include/asm/arch-sunxi/cpu.h | 3 +
> arch/arm/include/asm/arch-sunxi/dram.h | 2 +-
> arch/arm/include/asm/arch-sunxi/dram_sun8i_h3.h | 53 ++--
> arch/arm/include/asm/armv8/mmu.h | 8 -
> arch/arm/lib/Makefile | 2 +
> arch/arm/lib/spl.c | 15 +
> arch/arm/lib/vectors.S | 1 -
> arch/arm/mach-omap2/boot-common.c | 2 +-
> arch/arm/mach-sunxi/Makefile | 2 +
> arch/arm/mach-sunxi/board.c | 2 +-
> arch/arm/mach-sunxi/clock_sun6i.c | 10 +-
> arch/arm/mach-sunxi/dram_sun8i_h3.c | 400 +++++++++++++++++-------
> arch/arm/mach-sunxi/rmr_switch.S | 41 +++
> arch/arm/mach-sunxi/spl_switch.c | 81 +++++
> arch/arm/mach-tegra/spl.c | 2 +-
> board/sunxi/Kconfig | 41 ++-
> common/spl/spl.c | 9 +-
> common/spl/spl_fit.c | 8 +
> common/spl/spl_mmc.c | 2 +-
> configs/pine64_plus_defconfig | 7 +-
> configs/sun50i_spl32_defconfig | 10 +
> include/common.h | 13 +-
> include/configs/sunxi-common.h | 4 +-
> include/spl.h | 19 +-
> lib/tiny-printf.c | 50 ++-
> 34 files changed, 713 insertions(+), 201 deletions(-)
> create mode 100644 arch/arm/cpu/armv8/lowlevel_init.S
> create mode 100644 arch/arm/mach-sunxi/rmr_switch.S
> create mode 100644 arch/arm/mach-sunxi/spl_switch.c
> create mode 100644 configs/sun50i_spl32_defconfig
>
> --
> 2.8.2
>
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--
Jon Smirl
jonsmirl at gmail.com
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