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Command "dcache on" for MPC850 isn't valid

U-Boot-Users gshan 2 participants 4 messages Apr 11, 2007 – Apr 12, 2007

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gshan

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#0 lore raw

Hi All,

I got a problem recently and have to send this mail for resolution. The configuration I'm using:

CPU: MPC8xx
U-boot: 1.1.4
Linux : 2.6.15
ELDK : 4.0

As everyone knew, uboot for MPC850 didn't turn on data cache, but instruction cache is on. In order to test data cache, I added CFG_CMD_CACHE for CONFIG_COMMANDS. However, the CPU is spinning once I issue command "dcache on".

Any ideas on this?

Thanks,
Gavin

#1 lore raw
Quoted 2 lines · In message <[email protected]> you wrote:

As everyone knew, uboot for MPC850 didn't turn on data cache, but

Yes, and for a very good reason, which is explained in detail in the README.

Quoted 5 lines

instruction cache is on. In order to test data cache, I added CFG_CMD_CACHE for CONFIG_COMMANDS. However, the CPU is spinning once I issue command "dcache on".

Any ideas on this?

Read the README.

Best regards,

Wolfgang Denk

Signature · 6 lines
DENX Software Engineering GmbH, HRB 165235 Munich, CEO: Wolfgang Denk
Office:  Kirchenstr. 5,       D-82194 Groebenzell,            Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"If you'll excuse me a minute, I'm going to have a cup of coffee."
- broadcast from Apollo 11's LEM, "Eagle", to Johnson  Space  Center,
Houston July 20, 1969, 7:27 P.M.
author
#2 lore raw

Denk,

Thanks for your quick response. But linux kernel need to turn on data cache at head_8xx.S::initial_mmu.

Thanks,
Gavin

Quoted 23 lines · Wolfgang Denk
Quoted 2 lines · In message <[email protected]> you wrote:

As everyone knew, uboot for MPC850 didn't turn on data cache, but

Yes, and for a very good reason, which is explained in detail in the README.

Quoted 6 lines

instruction cache is on. In order to test data cache, I added CFG_CMD_CACHE for CONFIG_COMMANDS. However, the CPU is spinning once I issue command "dcache on".

Any ideas on this?

Read the README.

Best regards,

Wolfgang Denk

#3 lore raw
Quoted 3 lines · In message <[email protected]> you wrote:

Thanks for your quick response. But linux kernel need to turn on data cache at head_8xx.S::initial_mmu.

Yes. So what?

PLease don't top post / full quote. Read
http://www.netmeister.org/news/learn2quote.html

Best regards,

Wolfgang Denk

Signature · 5 lines
DENX Software Engineering GmbH, HRB 165235 Munich, CEO: Wolfgang Denk
Office:  Kirchenstr. 5,       D-82194 Groebenzell,            Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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