[U-Boot-Users] SYNC definition problem

[Yang Ronda]

Hi,
 
I was trying to turn on I-Cache while u-boot is executing out of Flash
on MPC5121 ADS board, and just found the board refused to boot. After
debug and tried many different ways, we finally found that the root of
the problem is the SYNC macro definition in u-boot include/ppc_asm.tmpl
file. The SYNC was defined as
 
#define SYNC \
 sync; \
 isync

By turning on I-cache on powerpc e300 core, ICE bit of HID0 needs to be
set. Before setting ICE, an isync operation need to be issued. In the
cpu/mpc512x/start.S file, this is done by using a 'SYNC' statement. But
we found we need to add one more sync operation to guarantee isync is
complete. 
 
I think it is more safe to change the SYNC definition in ppc_asm.tmpl to
the following,
 
#define SYNC \
 sync; \
 isync; \
 sync

Just a suggestion. 
 
 
Best Regards,
Ronda

 
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