Hello J. Where are you? You promised to have a look. I can't remove the "disclaimer". Sorry for this.
Regards Amit Kumar -----Original Message----- From: Jean-Christophe PLAGNIOL-VILLARD [mailto:[EMAIL PROTECTED] Sent: Friday, May 16, 2008 2:41 PM To: Amit Kumar Cc: u-boot-users@lists.sourceforge.net; Yadvinder Singh Mann Subject: Re: [U-Boot-Users] PXA255 code in start.S On 12:14 Fri 16 May , Amit Kumar wrote: > > > Hello, > > Kindly refer code at path UBOOT / u-boot / cpu / pxa / > start.S > > > > Code: > > .macro irq_save_user_regs > > sub sp, sp, #S_FRAME_SIZE > > stmia sp, {r0 - r12} /* Calling r0-r12 */ > > add r8, sp, #S_PC > > stmdb r8, {sp, lr}^ /* Calling SP, LR */ > > str lr, [r8, #0] /* Save calling PC */ > > mrs r6, spsr > > str r6, [r8, #4] /* Save CPSR */ > > str r0, [r8, #8] /* Save OLD_R0 */ > > mov r0, sp > > .endm > > > > Why there is need to save R0? If we refer ARM architecture (section what > all happens when interrupt comes) there is no need to save R0. > > > > Moreover, there is no need of writing such big piece of code it can be > replaced with below given four liner code: > > > > Sub lr, lr, #4 > > Stmfd sp! , {r0-r12, lr} > > MRS r1, spsr > > Stmfd sp! , {r1} > > > > Similarly we can write small code for restore of stack > > .macro irq_restore_user_regs > > Ldmfd sp! , {r1} > > MSR cpsr_c , R1 > ldmfd sp!, {r0-r12, pc}^ > > .endm > > > > Can anybody clarify? I'll take a look, I'm currently cleaning the board init Please do NOT post as HTML > > > > Regards > > Amit Kumar > Please remove this to Best Regards, J. **************** CAUTION - Disclaimer ***************** This e-mail contains PRIVILEGED AND CONFIDENTIAL INFORMATION intended solely for the use of the addressee(s). If you are not the intended recipient, please notify the sender by e-mail and delete the original message. Further, you are not to copy, disclose, or distribute this e-mail or its contents to any other person and any such actions are unlawful. This e-mail may contain viruses. Infosys has taken every reasonable precaution to minimize this risk, but is not liable for any damage you may sustain as a result of any virus in this e-mail. You should carry out your own virus checks before opening the e-mail or attachment. Infosys reserves the right to monitor and review the content of all messages sent to or from this e-mail address. Messages sent to or from this e-mail address may be stored on the Infosys e-mail system. ***INFOSYS******** End of Disclaimer ********INFOSYS*** ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ U-Boot-Users mailing list U-Boot-Users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/u-boot-users