[U-Boot] [PATCH u-boot-marvell v3 09/10] board: turris_mox: Support 1 GB version of Turris Mox

[Marek Behún]

Hi Stefan,

get_ram_size does not work correctly on Mox. On a 512 MiB board it
detects 1024 MiB of RAM, because on the 512 MiB RAM chip the topmost
address bit is simply ignored and the RAM wraps - on
0x20000000-0x40000000 CPU sees the same data as on 0x0-0x20000000.

ATF does not run RAM size determining code either, it just gets RAM
size from a register, this register is written before ATF by BootROM
and we have done it so that there is always 1 GB so that we could use
same secure firmware image for all Moxes. I tried to change this
register in secure firmware, but this lead to Synchornous Abort events
in U-Boot.

Maybe we could move the dram_init funcitons from arm64-common.c to
specific board files, or maybe we could declare them __weak in
arm64-common.c and turris_mox can then redefine them.

Would that be OK with you?

Marek

On Thu, 29 Nov 2018 14:07:59 +0100
Stefan Roese <sr at denx.de> wrote:

> On 20.11.18 13:04, Marek Behún wrote:
> > Depending on the data in the OTP memory, differentiate between the
> > 512 MiB and 1 GiB versions of Turris Mox and report these RAM sizes
> > in dram_init and dram_init_banksize.
> > 
> > Signed-off-by: Marek Behún <marek.behun at nic.cz>
> > ---
> >   arch/arm/mach-mvebu/arm64-common.c   |  7 ++++++-
> >   board/CZ.NIC/turris_mox/turris_mox.c | 27
> > +++++++++++++++++++++++++++ 2 files changed, 33 insertions(+), 1
> > deletion(-)
> > 
> > diff --git a/arch/arm/mach-mvebu/arm64-common.c
> > b/arch/arm/mach-mvebu/arm64-common.c index f47273fde9..5e6ac9fc4a
> > 100644 --- a/arch/arm/mach-mvebu/arm64-common.c
> > +++ b/arch/arm/mach-mvebu/arm64-common.c
> > @@ -43,8 +43,12 @@ const struct mbus_dram_target_info
> > *mvebu_mbus_dram_info(void) return NULL;
> >   }
> >   
> > -/* DRAM init code ... */
> > +/*
> > + * DRAM init code ...
> > + * Turris Mox defines this itself, depending on data in burned
> > eFuses
> > + */
> >   
> > +#ifndef CONFIG_TARGET_TURRIS_MOX
> >   int dram_init_banksize(void)
> >   {
> >   	fdtdec_setup_memory_banksize();
> > @@ -59,6 +63,7 @@ int dram_init(void)
> >   
> >   	return 0;
> >   }
> > +#endif /* !CONFIG_TARGET_TURRIS_MOX */  
> 
> 2 Problems with this:
> 
> a)
> This does not apply any more with the latest changes in mainline.
> 
> b)
> I really don't like #ifdef's here in this common code. Can you not
> get rid of this somehow? Isn't the turris_mox also using ATF and
> will read the RAM size from there?
> 
> U-Boot still has the good old get_ram_size() function, which can
> easily auto-detect 512MiB vs 1GiB when run with 1GiB as parameter.
> 
> Thanks,
> Stefan
> 
> >   
> >   int arch_cpu_init(void)
> >   {
> > diff --git a/board/CZ.NIC/turris_mox/turris_mox.c
> > b/board/CZ.NIC/turris_mox/turris_mox.c index 89b3cd2ce0..9aa2fc004d
> > 100644 --- a/board/CZ.NIC/turris_mox/turris_mox.c
> > +++ b/board/CZ.NIC/turris_mox/turris_mox.c
> > @@ -14,6 +14,7 @@
> >   #include <linux/string.h>
> >   #include <linux/libfdt.h>
> >   #include <fdt_support.h>
> > +#include <environment.h>
> >   
> >   #ifdef CONFIG_WDT_ARMADA_37XX
> >   #include <wdt.h>
> > @@ -40,6 +41,32 @@
> >   
> >   DECLARE_GLOBAL_DATA_PTR;
> >   
> > +int dram_init(void)
> > +{
> > +	int ret, ram_size;
> > +
> > +	gd->ram_base = 0;
> > +	gd->ram_size = (phys_size_t)0x20000000;
> > +
> > +	ret = mbox_sp_get_board_info(NULL, NULL, NULL, NULL,
> > &ram_size);
> > +	if (ret < 0) {
> > +		puts("Cannot read RAM size from OTP, defaulting to
> > 512 MiB");
> > +	} else {
> > +		if (ram_size == 1024)
> > +			gd->ram_size = (phys_size_t)0x40000000;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +int dram_init_banksize(void)
> > +{
> > +	gd->bd->bi_dram[0].start = (phys_addr_t)0;
> > +	gd->bd->bi_dram[0].size = gd->ram_size;
> > +
> > +	return 0;
> > +}
> > +
> >   #if defined(CONFIG_OF_BOARD_FIXUP)
> >   int board_fix_fdt(void *blob)
> >   {
> >   
> 
> Viele Grüße,
> Stefan
>