[U-Boot] [PATCH] am33xx, spl, siemens: enable debug uart output again

Tom Rini trini at konsulko.com
Thu Mar 5 15:50:52 CET 2015


On Thu, Mar 05, 2015 at 09:46:50AM +0100, Heiko Schocher wrote:
> Hello Tom,
> 
> Am 05.03.2015 07:22, schrieb Heiko Schocher:
> >Hello Tom,
> >
> >Am 04.03.2015 17:40, schrieb Tom Rini:
> >>On Wed, Mar 04, 2015 at 08:42:58AM +0100, Heiko Schocher wrote:
> >>>Hello Tom,
> >>>
> >>>Am 02.03.2015 14:59, schrieb Tom Rini:
> >>>>On Mon, Mar 02, 2015 at 07:56:41AM +0100, Heiko Schocher wrote:
> >>>>>Hello Simon,
> >>>>>
> >>>>>Am 24.02.2015 14:31, schrieb Simon Glass:
> >>>>>>Hi Heiko,
> >>>>>>
> >>>>>>On 23 February 2015 at 23:18, Heiko Schocher <hs at denx.de> wrote:
> >>>>>>>a6b541b090: TI ARMv7: Don't use GD before crt0.S has set it
> >>>>>>>
> >>>>>>>moves the init of the debug uart at the very end of SPL code.
> >>>>>>>Enable it for the siemens board earlier, as they print
> >>>>>>>ddr settings ... all debug output before board_init_r()
> >>>>>>>is here currently useless. Maybe we must rework this
> >>>>>>>globally?
> >>>>>>
> >>>>>>Assuming we are talking about U-Boot proper, the DDR init should
> >>>>>>happen in board_init_f(), specifically dram_init(). so I think this
> >>>>>>code should be updated.
> >>>>>>
> >>>>>>If it is SPL, then DDR init should happen in SPL's board_init_f().
> >>>>>
> >>>>>It is in SPL...
> >>>>>
> >>>>>sdram_init() is called from:
> >>>>>
> >>>>>./arch/arm/cpu/armv7/am33xx/board.c from s_init() ...
> >>>>>
> >>>>>>I sent a series a few weeks ago (available at u-boot-dm branch
> >>>>>>spl-working) related to this topic:
> >>>>>>
> >>>>>>http://patchwork.ozlabs.org/patch/438581/
> >>>>>
> >>>>>Ah ... Hmm... so "./arch/arm/cpu/armv7/am33xx/board.c" needs
> >>>>>a rework, right?
> >>>>>
> >>>>>Is a simple rename s_init() -> board_init_f() correct?
> >>>>
> >>>>Right so, no, we can't just rename s_init to board_init_f.  This is what
> >>>>I was talking about in the thread about the function Hans wants to add
> >>>>to enable some bits in CP15 on sunxi, iirc.
> >>>>
> >>>>In short, armv7 has a different set of abstraction hooks than the
> >>>>previous ARM cores (armv8 followed what we have for v7) and I'm not
> >>>>convinced in the end that it really won us anything.  See
> >>>>http://lists.denx.de/pipermail/u-boot/2015-January/202350.html
> >>>>
> >>>>For today you need to rework the Siemens code to print out the DDR
> >>>>values (when desired) in spl_board_init() as we do not, or will not
> >>>>shortly, have gd prior to board_init_f running.
> >>>
> >>>Hmm... first I thought, ok, no problem, move the output from the RAM
> >>>parameters to spl_board_init() ... but thats only the half of the
> >>>story ... They read the RAM parameters from an i2c eeprom, and if
> >>>there are errors, they print this errors ... currently this does
> >>>not work, and thats I think the more important case ... and I could
> >>>not move this error printfs to somewhere, because if RAM is not
> >>>working ... there is no later ...
> >>>
> >>>So I have to enable the console early ... maybe I missed something,
> >>>but this worked fine in the past (and I think we should not break
> >>>this, as this is an essential feature).
> >>
> >>OK, I missed something too.  I think this gets better now once I merge
> >>Simon's SPL series as we do all of this from board_init_f() and the
> >>siemens code should just work again.
> >
> >Yes, just saw your patch ;-)
> >
> >If they are in mainline (or do you have them somewhere in a git repo?),
> >I test it again on the dxr2 board, thanks!
> 
> If I am correct, all needed patches from you are in mainline, just
> tried this on the dxr2 board ... but I still need:
> 
> diff --git a/board/siemens/common/board.c b/board/siemens/common/board.c
> index a39cbd0..8724604 100644
> --- a/board/siemens/common/board.c
> +++ b/board/siemens/common/board.c
> @@ -40,6 +40,11 @@ void set_uart_mux_conf(void)
> 
>  void set_mux_conf_regs(void)
>  {
> +       /* enable early the console */
> +       gd->baudrate = CONFIG_BAUDRATE;
> +       serial_init();
> +       gd->have_console = 1;
> +
>         /* Initalize the board header */
>         enable_i2c0_pin_mux();
>         i2c_set_bus_num(0);
> 
> to see the console output ...

Yes, if you want console prior to spl_board_init() then you need to do
that where you are.

-- 
Tom
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