Re: [U-Boot-Users] u-boot hangs in ./cpu/mpc8xx/cpu_init.c when changing br0

You did read http://www.denx.de/wiki/view/DULG/DebuggingTricks , didn't

you?

I did, but those compiler flags were in by board directory, I moved them to the makefile in the top directory, and this simplifies watching the code.

But back to the problem.

./cpu/mpc8xx/cpu_init.c

In "C": 118 reg = memctl->memc_br0; 119 reg &= BR_PS_MSK; /* Clear everything except Port Size bits */ 120 reg |= BR_V; /* then add just the "Bank Valid" bit */ 121 memctl->memc_br0 = reg;

In Assembly, this compiles to: Ln 118 0xff007ce4 <cpu_init_f+172>: lwz r0,0(r28) Ln 119 0xff007ce8 <cpu_init_f+176>: rlwinm r0,r0,0,20,21 Ln 120 0xff007cec <cpu_init_f+180>: ori r0,r0,1 Ln 121 0xff007cf0 <cpu_init_f+184>: stw r0,0(r28)

r28 holds the value 0xfa200100 (the location of br0) At line 118, br0 is loaded into r0. r0 then holds 0xfc000001. At line 119, r0 becomes 0x00000000. <<-- This is the problem, I think At line 120, r0 becomes 0x00000001 At line 121, r0 is saved to br0 (the address pointed to by r28). (br0 becomes 0x00000001)

in ./include/mpc8xx.h: #define BR_PS_MSK 0x00000C00 Is this right?

The program fails at ln 180 with: "Program received signal SIGABRT, aborted." But by this time, br0 was reloaded with CFG_BR0_PRELIM from line 176.

Any more ideas? Thanks, JM

-----Original Message----- From: wd@denx.de [mailto:wd@denx.de] Sent: Tuesday, June 20, 2006 5:53 PM To: Jeff Mann Cc: u-boot-users@lists.sourceforge.net Subject: Re: [U-Boot-Users] u-boot hangs in ./cpu/mpc8xx/cpu_init.c when changing br0

In message 1628E43D99629C46988BE46087A3FBB95C57DD@ep-01.EmbeddedPlanet.local you wrote:

reg does not get the value of br0 at line 118, like it should. In fact, DDD acts like the variable does not even exist. So at line 121, br0 is

...

Any suggestions?

You did read http://www.denx.de/wiki/view/DULG/DebuggingTricks , didn't you?

Best regards,

Wolfgang Denk

-- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de The light at the end of the tunnel is usually a "No Exit" sign.