Re: [U-Boot] [PATCH 1/4] doc: Add documentation for mpc85xx debugger support
Hi Scott, On Thursday 15 March 2012 01:00 AM, Scott Wood wrote: On 03/14/2012 04:35 AM, Prabhakar Kushwaha wrote: Hi Wolfgang, On Tuesday 13 March 2012 12:44 PM, Prabhakar Kushwaha wrote: Hi Wolfgang, On Wednesday 07 March 2012 06:00 PM, Wolfgang Denk wrote: Dear Prabhakar Kushwaha, In message<4f572159.9020...@freescale.com> you wrote: Also, what's the "V1_V2" ? Are there also other systems (say, e500 v3 cores), and are this not affected? We already have CONFIG_E500 and CONFIG_E500MC so CONFIG_E500_V1_V2 appears to belong to this group, but if I understand your intentions it does something completely unrelated. V1_V2 is used because it applied to e500v1 and e500v2 not e500mc processor. So CONFIG_E500MC cant be used. Also I cant use CONFIG_E500 as it refer the entire e500 family which includes e500mc. Hm... I am not sure if CONFIG_E500 was supposed to include CONFIG_E500MC; it's nowhere documented. Let's assume it is. What happens if you enable this code on a E500MC system? Debug restrictions are not valid for e500mc system. At first sight it should not hurt e500mc execution (other than some seemingly unnecessary steps). However i will check this point. We tried by enabling CONFIG_E500_V2_V2 for E500MC with u-boot patches. It boots fine and debugging can be done. Be sure to mention in comments that the hack is only really needed for v1/v2. I will clearly mention in doc So, we can use CONFIG_E500 #define instead of CONFIG_E500_V2_V2 i.e. debugging will always be enabled. One have to define CONFIG_DEBUGGER_TEMP_TLB for debugging in AS1 ( Part of patch "powerpc/85xx:Update NOR code base to support debugger" ) CONFIG_SYS_PPC_E500_DEBUG_TLB OK CONFIG_DEBUGGER_TEMP_TLB can also be used for placing code which can only be required during debugging (specially code of temporary TLB creation) Is there something specific you had in mind, other than the use that is already present in this patchset? There is no specific use case in my mind other than the patch-set. Actually, Wolfgang is having concern about code size increase because of "temporary TLB creation" in start.S for debugging. That's why i am planning to use this #define for "temporary TLB creation" --Prabhakar ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [PATCH 1/4] doc: Add documentation for mpc85xx debugger support
On 03/14/2012 04:35 AM, Prabhakar Kushwaha wrote: > Hi Wolfgang, > > On Tuesday 13 March 2012 12:44 PM, Prabhakar Kushwaha wrote: >> Hi Wolfgang, >> >> On Wednesday 07 March 2012 06:00 PM, Wolfgang Denk wrote: >>> Dear Prabhakar Kushwaha, >>> >>> In message<4f572159.9020...@freescale.com> you wrote: > Also, what's the "V1_V2" ? Are there also other systems (say, e500 v3 > cores), and are this not affected? We already have CONFIG_E500 and > CONFIG_E500MC so CONFIG_E500_V1_V2 appears to belong to this group, > but if I understand your intentions it does something completely > unrelated. V1_V2 is used because it applied to e500v1 and e500v2 not e500mc processor. So CONFIG_E500MC cant be used. Also I cant use CONFIG_E500 as it refer the entire e500 family which includes e500mc. >>> Hm... I am not sure if CONFIG_E500 was supposed to include >>> CONFIG_E500MC; it's nowhere documented. Let's assume it is. >>> >>> What happens if you enable this code on a E500MC system? >>> >> >> Debug restrictions are not valid for e500mc system. >> >> At first sight it should not hurt e500mc execution (other than some >> seemingly unnecessary steps). However i will check this point. >> > We tried by enabling CONFIG_E500_V2_V2 for E500MC with u-boot patches. > It boots fine and debugging can be done. Be sure to mention in comments that the hack is only really needed for v1/v2. > So, we can use CONFIG_E500 #define instead of CONFIG_E500_V2_V2 i.e. > debugging will always be enabled. One have to define > CONFIG_DEBUGGER_TEMP_TLB for debugging in AS1 ( Part of patch > "powerpc/85xx:Update NOR code base to support debugger" ) CONFIG_SYS_PPC_E500_DEBUG_TLB > CONFIG_DEBUGGER_TEMP_TLB can also be used for placing code which can > only be required during debugging (specially code of temporary TLB > creation) Is there something specific you had in mind, other than the use that is already present in this patchset? -Scott ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [PATCH 1/4] doc: Add documentation for mpc85xx debugger support
Hi Wolfgang, On Tuesday 13 March 2012 12:44 PM, Prabhakar Kushwaha wrote: Hi Wolfgang, On Wednesday 07 March 2012 06:00 PM, Wolfgang Denk wrote: Dear Prabhakar Kushwaha, In message<4f572159.9020...@freescale.com> you wrote: Also, what's the "V1_V2" ? Are there also other systems (say, e500 v3 cores), and are this not affected? We already have CONFIG_E500 and CONFIG_E500MC so CONFIG_E500_V1_V2 appears to belong to this group, but if I understand your intentions it does something completely unrelated. V1_V2 is used because it applied to e500v1 and e500v2 not e500mc processor. So CONFIG_E500MC cant be used. Also I cant use CONFIG_E500 as it refer the entire e500 family which includes e500mc. Hm... I am not sure if CONFIG_E500 was supposed to include CONFIG_E500MC; it's nowhere documented. Let's assume it is. What happens if you enable this code on a E500MC system? Debug restrictions are not valid for e500mc system. At first sight it should not hurt e500mc execution (other than some seemingly unnecessary steps). However i will check this point. We tried by enabling CONFIG_E500_V2_V2 for E500MC with u-boot patches. It boots fine and debugging can be done. So, we can use CONFIG_E500 #define instead of CONFIG_E500_V2_V2 i.e. debugging will always be enabled. One have to define CONFIG_DEBUGGER_TEMP_TLB for debugging in AS1 ( Part of patch "powerpc/85xx:Update NOR code base to support debugger" ) CONFIG_DEBUGGER_TEMP_TLB can also be used for placing code which can only be required during debugging (specially code of temporary TLB creation) Please suggest. Regards, Prabhakar ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [PATCH 1/4] doc: Add documentation for mpc85xx debugger support
Hi Wolfgang, On Wednesday 07 March 2012 06:00 PM, Wolfgang Denk wrote: Dear Prabhakar Kushwaha, In message<4f572159.9020...@freescale.com> you wrote: Also, what's the "V1_V2" ? Are there also other systems (say, e500 v3 cores), and are this not affected? We already have CONFIG_E500 and CONFIG_E500MC so CONFIG_E500_V1_V2 appears to belong to this group, but if I understand your intentions it does something completely unrelated. V1_V2 is used because it applied to e500v1 and e500v2 not e500mc processor. So CONFIG_E500MC cant be used. Also I cant use CONFIG_E500 as it refer the entire e500 family which includes e500mc. Hm... I am not sure if CONFIG_E500 was supposed to include CONFIG_E500MC; it's nowhere documented. Let's assume it is. What happens if you enable this code on a E500MC system? Debug restrictions are not valid for e500mc system. At first sight it should not hurt e500mc execution (other than some seemingly unnecessary steps). However i will check this point. Regards, Prabhakar ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [PATCH 1/4] doc: Add documentation for mpc85xx debugger support
Dear Prabhakar Kushwaha, In message <4f572159.9020...@freescale.com> you wrote: > > > Also, what's the "V1_V2" ? Are there also other systems (say, e500 v3 > > cores), and are this not affected? We already have CONFIG_E500 and > > CONFIG_E500MC so CONFIG_E500_V1_V2 appears to belong to this group, > > but if I understand your intentions it does something completely > > unrelated. > V1_V2 is used because it applied to e500v1 and e500v2 not e500mc > processor. So CONFIG_E500MC cant be used. Also I cant use CONFIG_E500 as > it refer the entire e500 family which includes e500mc. Hm... I am not sure if CONFIG_E500 was supposed to include CONFIG_E500MC; it's nowhere documented. Let's assume it is. What happens if you enable this code on a E500MC system? Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de Software suppliers are trying to make their software packages more ``user-friendly''. . . . Their best approach, so far, has been to take all the old brochures, and stamp the words, ``user-friendly'' on the cover. - Bill Gates ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [PATCH 1/4] doc: Add documentation for mpc85xx debugger support
Hi Wolfgang, On Wednesday 07 March 2012 11:54 AM, Wolfgang Denk wrote: In message<071a08f2c6a57e4e94d980eca553f874575...@039-sn1mpn1-005.039d.mgd.msft.net> you wrote: Regarding CONFIG_E500_V1_V2, Its description is also part of this patch or is it not cleared ? First, documentation of CONFIG_ options belongs into the central README, so we have it all in a single place. I will take care in next version. Second, "Enables code taking care of above mentioned rule" is not really helpful to understand what it's actually doing. I will add more description The name of the cvariable suggests that this defiens a E500 core based system, but it does not even contain a slight hint that it has something to do with debugging. Yes i agree. From #define no one can get hint of debugging. It was intended. This #define is created to overcome restriction of e500 v1 and v2 family processor. We can have this #define permanently enabled. That's why i did not create any CONFIG_ having DBG name. Unfortunately this is a restriction for debugging. Also, what's the "V1_V2" ? Are there also other systems (say, e500 v3 cores), and are this not affected? We already have CONFIG_E500 and CONFIG_E500MC so CONFIG_E500_V1_V2 appears to belong to this group, but if I understand your intentions it does something completely unrelated. V1_V2 is used because it applied to e500v1 and e500v2 not e500mc processor. So CONFIG_E500MC cant be used. Also I cant use CONFIG_E500 as it refer the entire e500 family which includes e500mc. Thinking over lot of confusion over #define i should use CONFIG_E500_V1_V2_DBG. Please guide me in having correct #define. Regards, Prabhakar ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [PATCH 1/4] doc: Add documentation for mpc85xx debugger support
Dear Kushwaha Prabhakar-B32579, In message <071a08f2c6a57e4e94d980eca553f874575...@039-sn1mpn1-005.039d.mgd.msft.net> you wrote: > > Regarding CONFIG_E500_V1_V2, Its description is also part of this > patch or is it not cleared ? First, documentation of CONFIG_ options belongs into the central README, so we have it all in a single place. Second, "Enables code taking care of above mentioned rule" is not really helpful to understand what it's actually doing. The name of the cvariable suggests that this defiens a E500 core based system, but it does not even contain a slight hint that it has something to do with debugging. Also, what's the "V1_V2" ? Are there also other systems (say, e500 v3 cores), and are this not affected? We already have CONFIG_E500 and CONFIG_E500MC so CONFIG_E500_V1_V2 appears to belong to this group, but if I understand your intentions it does something completely unrelated. All this is highly confusing. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de If you hear an onion ring, answer it. ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [PATCH 1/4] doc: Add documentation for mpc85xx debugger support
Hi Wolfgang, Thanks for reviewing this patch. Please find my response in-lined On Tuesday 06 March 2012 08:09 PM, Wolfgang Denk wrote: Dear Prabhakar Kushwaha, In message<1329296027-28471-1-git-send-email-prabha...@freescale.com> you wrote: This describes requirement of e500 and e500v2 processor to support any debugger. it also provide an insight of switch used and defined. Signed-off-by: Radu Lazarescu Signed-off-by: Prabhakar Kushwaha --- Applies on http://git.denx.de/u-boot.git branch master doc/README.mpc85xx_debugger | 44 +++ 1 files changed, 44 insertions(+), 0 deletions(-) create mode 100644 doc/README.mpc85xx_debugger This document contains a number of typos and othe rerrors, mixed with inconsitent indentation (some lines use TABs, others use spaces). I suggest you clean it up and have it reviewed by a native speaker before resubmitting. I will take care of your review-comments and will have first review at native level before floating it again. Regarding the split into 4 separate patches: this makes no sense to me. For example, in this patch you reference new (and undocumented config options like CONFIG_E500_V1_V2) without ever using them. Please squash patches. My objective was to have separate patch for every logical piece. That's why I sent a series of patch. I will request you to let them as series for better understanding of others. May be in each patch before use of any #define (related to debugger), I will write a comment. Please suggest. Regarding CONFIG_E500_V1_V2, Its description is also part of this patch or is it not cleared ? --Prabhakar ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [PATCH 1/4] doc: Add documentation for mpc85xx debugger support
Dear Prabhakar Kushwaha, In message <1329296027-28471-1-git-send-email-prabha...@freescale.com> you wrote: > This describes requirement of e500 and e500v2 processor to support any > debugger. it also provide an insight of switch used and defined. > > Signed-off-by: Radu Lazarescu > Signed-off-by: Prabhakar Kushwaha > --- > Applies on http://git.denx.de/u-boot.git branch master > > doc/README.mpc85xx_debugger | 44 > +++ > 1 files changed, 44 insertions(+), 0 deletions(-) > create mode 100644 doc/README.mpc85xx_debugger This document contains a number of typos and othe rerrors, mixed with inconsitent indentation (some lines use TABs, others use spaces). I suggest you clean it up and have it reviewed by a native speaker before resubmitting. Regarding the split into 4 separate patches: this makes no sense to me. For example, in this patch you reference new (and undocumented config options like CONFIG_E500_V1_V2) without ever using them. Please squash patches. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de "The two most common things in the universe are hydrogen and stupi- dity." ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
[U-Boot] [PATCH 1/4] doc: Add documentation for mpc85xx debugger support
This describes requirement of e500 and e500v2 processor to support any debugger. it also provide an insight of switch used and defined. Signed-off-by: Radu Lazarescu Signed-off-by: Prabhakar Kushwaha --- Applies on http://git.denx.de/u-boot.git branch master doc/README.mpc85xx_debugger | 44 +++ 1 files changed, 44 insertions(+), 0 deletions(-) create mode 100644 doc/README.mpc85xx_debugger diff --git a/doc/README.mpc85xx_debugger b/doc/README.mpc85xx_debugger new file mode 100644 index 000..b35d710 --- /dev/null +++ b/doc/README.mpc85xx_debugger @@ -0,0 +1,44 @@ +Overview + +Debugger's ability to debug an application is constrained by the +architecture's debug IP / run-control solution that may impose certain +requirements for the application itself. + +Similarly, when referring to the e500 and e500v2 architecture, there are two +basic rules any application has to respect in order to allow full debugging +support: +1. Keep MSR[DE] bit set +2. Have a valid opcode that can be fetched from the debug exception + vector [IVPR|IVOR15]. +Where: + MSR : Machine State register + IVPR : Interrupt Vector Prefix Register + IVOR : Interrupt Vector Offset Register + +Depending upon above 2 points there various place in powerpc/mpc85xx/ code +which break the rules: + - MSR[DE] is not se +- Changing the context with a rfi instruction, but omitting to preserve + the [DE] bit in SRR1 + - Changing IVPR/IVOR15 to a new location, before that location is + un-accessible +- Changing IVPR/IVOR15 to a location that does not have a valid opcode + at [IVOR|IVOR15] + - While executing in translated space (AS=1), whenever a debug + exception is generated, the MSR[DS/IS] gets cleared and the processor + tries to fetch an instruction from the debug exception vector + (IVPR|IVOR15); since now we are in AS=0, the application needs to + ensure the proper configuration to have IVOR|IVOR15 accessible from + AS=0 also + +Config Switches: + +CONFIG_E500_V1_V2 Enables code taking care of above mentioned rule. +CONFIG_DEBUGGER_TEMP_TLB Define temporary TLB number. + It will be used to create temporary TLB for AS0 + during execution in AS1. The TLB entry will be + created for debug exception vector. + Becuase on debug exception MSR[DS/IS] get + cleared i.e. execution space is shifted back + to AS0 and a TLB is required to have debug + exception vecor accessible. -- 1.7.5.4 ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
