[U-Boot] arm: socfpga: Repair SoCrates board

[Marek Vasut]

On Monday, November 23, 2015 at 03:12:48 PM, Jan Viktorin wrote:
> Hello again,
> 
> I have a couple of short questions bellow...
> 
> On Fri, 20 Nov 2015 17:17:33 +0100
> 
> Marek Vasut <marex at denx.de> wrote:
> > [snip]
> > +/* Booting Linux */
> > +#define CONFIG_BOOTDELAY	3
> > +#define CONFIG_BOOTFILE		"zImage"
> 
> This is quite a general question. Why would one prefer zImage over
> uImage (or vice-versa)? Is there some mainstream idea with this? Or is
> it selected at random?

General rule is to use fitImage if you want the extended features. zImage
was picked by altera some time ago, so it just sticks for no real reason.
uImage is deprecated/legacy for years.

> > +#define CONFIG_BOOTARGS		"console=ttyS0," 
__stringify(CONFIG_BAUDRATE)
> > +#define CONFIG_BOOTCOMMAND	"run mmcload; run mmcboot"
> > [snip]
> > +
> > +#define CONFIG_EXTRA_ENV_SETTINGS \
> > +	"verify=n\0" \
> > +	"loadaddr= " __stringify(CONFIG_SYS_LOAD_ADDR) "\0" \
> > +	"ramboot=setenv bootargs " CONFIG_BOOTARGS ";" \
> > +		"bootm ${loadaddr} - ${fdt_addr}\0" \
> > +	"bootimage=zImage\0" \
> > +	"fdt_addr=100\0" \
> > +	"fdtimage=socfpga.dtb\0" \
> > +		"fsloadcmd=ext2load\0" \
> > +	"bootm ${loadaddr} - ${fdt_addr}\0" \
> > +	"mmcroot=/dev/mmcblk0p2\0" \
> > [snip]
> > +	"mmcload=mmc rescan;" \
> > +		"load mmc 0:1 ${loadaddr} ${bootimage};" \
> > +		"load mmc 0:1 ${fdt_addr} ${fdtimage}\0" \
> 
> The FAT partition is supposed to be the first and the Linux one as the
> second. So the boot partition is to be placed at the end of the SD card.

Not necessarily, the 0xa2 partition can be placed at arbitrary location.

> I find it quite weird as it makes the fdisk call more complex then
> necessary. I have to compute the position of the boot partition based
> on the size of the SD card. If I just create the paritions in the (say)
> natural order a2, b, 83 everything is pretty straight-forward.

That's right.

> So, what is the reason of this? Why anybody likes to use such layout?

That's what the EBV SD card ships with, but this can be changed easily.

Best regards,
Marek Vasut