[U-Boot-Users] start.S code snippet doubt

[Yuli Barcohen]

>>>>> Nishant Galange writes:

    Nishant> Hi all, What does the following code achieve: (Code snippet
    Nishant> from start.S) boot_cold:
    Nishant> #if defined(CONFIG_MPC8260ADS)
    Nishant> 	lis r3, CFG_DEFAULT_IMMR at h
    Nishant> 	nop
    Nishant> 	lwz r4, 0(r3)
    Nishant> 	nop
    Nishant> 	rlwinm r4, r4, 0, 8, 5
    Nishant> 	nop
    Nishant> 	oris r4, r4, 0x0200
    Nishant> 	nop
    Nishant>	stw r4,	0(r3)
    Nishant>	nop
    Nishant> #endif /* CONFIG_MPC8260ADS */

    Nishant> Can anyone please tell me the importance/significance of
    Nishant> this code?

This code fixes incorrect BADDR configuration caused by wrong HRCW
supplied by BCSR (FPGA) on some MPC8260ADS boards. It's configured as if
there was L2 cache so that lower address lines are not functional
(64-bit data bus). Without this code, such a board can't start from
32-bit flash SIMM. This code is for MPC8260ADS only so there should not
be any problem.

-- 
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 Yuli Barcohen       | Phone +972-9-765-1788 |  Software Project Leader
 yuli at arabellasw.com | Fax   +972-9-765-7494 | Arabella Software, Israel
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