[U-Boot] [PATCH v2 1/3] spl: mmc: support uboot image offset on main partition

[Baruch Siach]

Hi Stefan,

On Mon, Aug 12, 2019 at 03:13:58PM +0200, Stefan Roese wrote:
> On 06.08.19 08:15, Stefan Roese wrote:
> > On 29.07.19 09:12, Baruch Siach wrote:
> > > On Armada 38x platforms the ROM code loads SPL from offset 0 of eMMC
> > > hardware boot partitions. When there are no boot partitions (i.e. SD
> > > card) the ROM skips the first sector that usually contains the (logical)
> > > partition table. Since the generated .kwb image contains the main U-Boot
> > > image in a fixed location (0x140 sectors by default), we end up with the
> > > main U-Boot image in offset of 1 sector. The current workaround is to
> > > manually set CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR to 0x141 to
> > > compensate for that.
> > > 
> > > This patch uses the run-time detected boot partition to determine the
> > > right offset of the main U-Boot partition. The generated .kwb image is
> > > now compatible with both eMMC boot partition, and SD card main data
> > > partition.
> > > 
> > > Signed-off-by: Baruch Siach <baruch at tkos.co.il>
> > > ---
> > > v2: Rebase on top of current master
> > > ---
> > >    common/spl/Kconfig   | 12 ++++++++++++
> > >    common/spl/spl_mmc.c | 15 +++++++++++++--
> > >    2 files changed, 25 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/common/spl/Kconfig b/common/spl/Kconfig
> > > index 5d6da5db89bc..e43eefe046bc 100644
> > > --- a/common/spl/Kconfig
> > > +++ b/common/spl/Kconfig
> > > @@ -293,6 +293,18 @@ config SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR
> > >    	  Address on the MMC to load U-Boot from, when the MMC is being used
> > >    	  in raw mode. Units: MMC sectors (1 sector = 512 bytes).
> > > +config SYS_MMCSD_RAW_MODE_U_BOOT_DATA_PART_OFFSET
> > > +	hex "U-Boot main hardware partition image offset"
> > > +	depends on SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR
> > > +	default 0x0
> > > +	help
> > > +	  On some platforms SPL location depends on hardware partition. The ROM
> > > +	  code skips the MBR sector when loading SPL from main hardware data
> > > +	  partition. This adds offset to the main U-Boot image. Set this symbol
> > > +	  to the number of skipped sectors.
> > > +
> > > +	  If unsure, leave the default.
> > > +
> > >    config SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION
> > >    	bool "MMC Raw mode: by partition"
> > >    	help
> > > diff --git a/common/spl/spl_mmc.c b/common/spl/spl_mmc.c
> > > index b3619889f794..72439c029f4a 100644
> > > --- a/common/spl/spl_mmc.c
> > > +++ b/common/spl/spl_mmc.c
> > > @@ -49,6 +49,16 @@ static ulong h_spl_load_read(struct spl_load_info *load, ulong sector,
> > >    	return blk_dread(mmc_get_blk_desc(mmc), sector, count, buf);
> > >    }
> > > +static __maybe_unused unsigned long spl_mmc_raw_uboot_offset(int part)
> > > +{
> > > +#if IS_ENABLED(CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR)
> > 
> > Use if (IS_ENABLED()) instead ?

CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_DATA_PART_OFFSET is not defined when 
CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR is disabled. Using 'if 
(IS_ENABLED())' would break the build.

> > 
> > > +	if (part == 0)
> > 
> > Why is this restricted to part == 0 ?

As explained in the commit log, the ROM skips the first sector of the main 
data partition (where part == 0). Otherwise (where part != 0), the ROM load 
SPL from sector 0. That is the whole point of this patch set. Detect the SPL 
offset at run-time, instead of hard coding it at build time.

> Any updates on this?

Thanks for the reminder. I somehow missed your previous email.

baruch

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