[U-Boot] QSPI XIP boot on am437x

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

Hello Vignesh,

On Fri, 13 Nov 2015 11:22:19 +0530, Vignesh R <vigneshr@ti.com> wrote:
> Hi,
> 
> On 11/11/2015 02:33 PM, Albert ARIBAUD wrote:
> 
> [...]
> 
> > Alternatively, you could test the patch at
> > 
> > 	http://patchwork.ozlabs.org/patch/542558/
> > 
> > Let us know if this solves your issue. If it does, then it will confirm
> > the issue is with arch_setup_gd not being able to set up your GD for
> > some reason.
> > 
> > IMPORTANT: patch 542558 is *not* a final patch (there will be at least
> > a v3), and may even never land in u-boot/master; but some equivalent will
> > eventually do. Right now, patch 542558 is only a way to test if your
> > issue is a GD one.
> > 
> 
> The above patch affects the code that executes after s_init(), therefore
> I don't think above patch matters (_main is run after s_init()).

See (1) below.

> As you said in your first reply "If s_init() runs before
> board_init_f_mem(), then you must move it to
> run after board_init_f_mem().", this is the problem with my case.
> s_init() is running *before* setting up of global_data in
> arch/arm/lib/crt0.S (in _main), hence IMO, calling serial_init() in
> s_init() is wrong. This has to be moved to board_init_f() (in
> arch/arm/cpu/armv7/am33xx/board.c).
> The comment in arch/arm/cpu/armv7/lowlevel_init.S that calls s_init()
> also says *not* to access global_data and not to try to start console.
> Therefore, I intend to do something like this:
> 
> diff --git a/arch/arm/cpu/armv7/am33xx/board.c
> b/arch/arm/cpu/armv7/am33xx/board.c
> index bd14326cf479..351fc37b0483 100644
> --- a/arch/arm/cpu/armv7/am33xx/board.c
> +++ b/arch/arm/cpu/armv7/am33xx/board.c
> @@ -256,6 +256,11 @@ void board_init_f(ulong dummy)
>  {
>         board_early_init_f();
>         sdram_init();
> +#if defined(CONFIG_NOR_BOOT) || defined(CONFIG_QSPI_BOOT)
> +       gd->baudrate = CONFIG_BAUDRATE;
> +       serial_init();
> +       gd->have_console = 1;
> +#endif
>  }
>  #endif /* end  CONFIG_SPL_BUILD */
> 
> @@ -273,12 +278,6 @@ void s_init(void)
>         set_uart_mux_conf();
>         setup_clocks_for_console();
>         uart_soft_reset();
> -#if defined(CONFIG_NOR_BOOT) || defined(CONFIG_QSPI_BOOT)
> -       /* TODO: This does not work, gd is not available yet */
> -       gd->baudrate = CONFIG_BAUDRATE;
> -       serial_init();
> -       gd->have_console = 1;
> -#endif
>  #if defined(CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC)
>         /* Enable RTC32K clock */
>         rtc32k_enable();
> 
> Do you see any issues with above change?

(1) So your s_init runs even before board_init_f_mem(), right?

Your working fix seems to imply that as long as s_init() is run after
board_init_f_mem (and any time before board_init_f) it will work. If
so, then another, fix, preferable to the above, would be that the call
to s_init be moved between those to board_init_f_mem and board_init_f.
Can you test that?

Amicalement,
-- 
Albert.