[U-Boot-Users] U-Boot and MPC857T?

Steven Scholz
2003-07-02T11:36:07Z

Hi Gunnar,

> ...
> I also thought to that, but it is not so easy, because of at least the
> following Macros showed below.
>
> We have our board with a MPC855T 50 MHz and two prototypes with a MPC857T 100
> MHz. The CPU-Clock cannot be detected automatically. We need at
> least the following differences:
>
> #elif defined(CONFIG_100MHz) /* for 100 MHz = "50 MHz" |= SCCR_EBDF01 */
> #define CFG_SCCR (SCCR_TBS | SCCR_EBDF01 | \
> SCCR_COM00 | SCCR_DFSYNC00 | SCCR_DFBRG00 | \
> SCCR_DFNL000 | SCCR_DFNH000 | SCCR_DFLCD000 | \
> SCCR_RTSEL | SCCR_DFALCD00)
> #define CFG_PLPRCR ( (4-1)<<PLPRCR_MF_SHIFT | PLPRCR_TEXPS | PLPRCR_TMIST )
> #define CONFIG_8xx_GCLK_FREQ 100000000
> #else /* up to 50 MHz we use a 1:1 clock (CLKOUT=GCLK2) */
> #define CFG_SCCR (SCCR_TBS | \
> SCCR_COM00 | SCCR_DFSYNC00 | SCCR_DFBRG00 | \
> SCCR_DFNL000 | SCCR_DFNH000 | SCCR_DFLCD000 | \
> SCCR_RTSEL | SCCR_DFALCD00)
> #define CFG_PLPRCR ( (2-1)<<PLPRCR_MF_SHIFT | PLPRCR_TEXPS | PLPRCR_TMIST )
> #define CONFIG_8xx_GCLK_FREQ 50000000
> #endif /* CONFIG_...MHz */

Ehm... I don't understand. The code above only depends on
CONFIG_100MHz and not some CONFIG_MPC855T!
Of course you have to compile for a specific clock frequency. But it
shouldn't matter if it's a 855T or a 857T!

That's why I thought the FW (compiled for one specific clock) should
be able to detect the processor typ...

Steven