[U-Boot] [PATCH 3/4] powerpc/85xx:Update NOR code base to support debugger

[U-Boot] [PATCH 3/4] powerpc/85xx:Update NOR code base to support debugger

[Prabhakar Kushwaha]

Update the NOR code base to support NOR-boot debugging.
It ovecome e500 and e500v2's second limitation i.e. IVPR + IVOR15 should be
valid fetchable OP code address.

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.

Signed-off-by: Radu Lazarescu <radu.lazarescu@freescale.com>
Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
---
 Applies on http://git.denx.de/u-boot.git branch master

 arch/powerpc/cpu/mpc85xx/cpu_init_early.c |   32 +++++++++++++++++++++-
 arch/powerpc/cpu/mpc85xx/start.S          |   42 +++++++++++++++++++++++++++++
 arch/powerpc/include/asm/config_mpc85xx.h |    3 +-
 3 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/cpu/mpc85xx/cpu_init_early.c b/arch/powerpc/cpu/mpc85xx/cpu_init_early.c
index 091af7c..753f739 100644
--- a/arch/powerpc/cpu/mpc85xx/cpu_init_early.c
+++ b/arch/powerpc/cpu/mpc85xx/cpu_init_early.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2009-2011 Freescale Semiconductor, Inc
+ * Copyright 2009-2012 Freescale Semiconductor, Inc
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -53,6 +53,36 @@ void setup_ifc(void)
 
 	asm volatile("isync;msync;tlbwe;isync");
 
+#if defined(CONFIG_E500_V1_V2)
+/*
+ * TLB for debuggging in AS1
+ * Create temporary TLB in AS0 to handle debug exception
+ * As on debug exception MSR is cleared i.e. Address space is changed
+ * to 0. A TLB (in AS0) is required to handle debug exception generated
+ * in AS1.
+ *
+ * TLB is created for IVPR + IVOR15 to map on valid OP code address
+ * bacause flash's physical address is going to change as
+ * CONFIG_SYS_FLASH_BASE_PHYS.
+ */
+	_mas0 = MAS0_TLBSEL(1) |
+			MAS0_ESEL(CONFIG_DEBUGGER_TEMP_TLB);
+	_mas1 = MAS1_VALID | MAS1_TID(0) | MAS1_IPROT |
+			MAS1_TSIZE(BOOKE_PAGESZ_4M);
+	_mas2 = FSL_BOOKE_MAS2(CONFIG_SYS_TEXT_BASE, MAS2_I|MAS2_G);
+	_mas3 = FSL_BOOKE_MAS3(flash_phys, 0, MAS3_SW|MAS3_SR|MAS3_SX);
+	_mas7 = FSL_BOOKE_MAS7(flash_phys);
+
+	mtspr(MAS0, _mas0);
+	mtspr(MAS1, _mas1);
+	mtspr(MAS2, _mas2);
+	mtspr(MAS3, _mas3);
+	mtspr(MAS7, _mas7);
+
+	asm volatile("isync;msync;tlbwe;isync");
+#endif
+
+	/* Change flash's physical address */
 	out_be32(&(ifc_regs->cspr_cs[0].cspr), CONFIG_SYS_CSPR0);
 	out_be32(&(ifc_regs->csor_cs[0].csor), CONFIG_SYS_CSOR0);
 	out_be32(&(ifc_regs->amask_cs[0].amask), CONFIG_SYS_AMASK0);
diff --git a/arch/powerpc/cpu/mpc85xx/start.S b/arch/powerpc/cpu/mpc85xx/start.S
index 09111e6..26c32df 100644
--- a/arch/powerpc/cpu/mpc85xx/start.S
+++ b/arch/powerpc/cpu/mpc85xx/start.S
@@ -184,6 +184,48 @@ l2_disabled:
 	andi.	r1,r3,L1CSR0_DCE at l
 	beq	2b
 
+#if defined(CONFIG_E500_V1_V2) && !defined(CONFIG_SYS_RAMBOOT)
+/*
+ * TLB for debuggging in AS1
+ * Create temporary TLB in AS0 to handle debug exception
+ * As on debug exception MSR is cleared i.e. Address space is changed
+ * to 0. A TLB (in AS0) is required to handle debug exception generated
+ * in AS1.
+ *
+ * TLB is created for IVPR + IVOR15 to map on valid OP code address
+ * bacause flash's virtual address maps to 0xff800000 - 0xffffffff.
+ * and this window is outside of 4K boot window.
+ */
+
+	lis     r6,FSL_BOOKE_MAS0(1,
+			CONFIG_DEBUGGER_TEMP_TLB, 0)@h
+	ori     r6,r6,FSL_BOOKE_MAS0(1,
+			CONFIG_DEBUGGER_TEMP_TLB, 0)@l
+	lis     r7,FSL_BOOKE_MAS1(1, 1, 0, 0, BOOKE_PAGESZ_4M)@h
+	ori     r7,r7,FSL_BOOKE_MAS1(1, 1, 0, 0, BOOKE_PAGESZ_4M)@l
+
+	lis     r8,FSL_BOOKE_MAS2(CONFIG_SYS_MONITOR_BASE & 0xffc00000,
+							(MAS2_I|MAS2_G))@h
+	ori     r8,r8,FSL_BOOKE_MAS2(CONFIG_SYS_MONITOR_BASE & 0xffc00000,
+							(MAS2_I|MAS2_G))@l
+
+	/* The 85xx has the default boot window 0xff800000 - 0xffffffff */
+	lis     r9,FSL_BOOKE_MAS3(0xffc00000, 0, (MAS3_SX|MAS3_SW|MAS3_SR))@h
+	ori     r9,r9,FSL_BOOKE_MAS3(0xffc00000, 0, (MAS3_SX|MAS3_SW|MAS3_SR))@l
+
+	lis     r10,0xffc00000 at h
+	ori     r10,r10,0xffc00000 at l
+
+	mtspr   MAS0,r6
+	mtspr   MAS1,r7
+	mtspr   MAS2,r8
+	mtspr   MAS3,r9
+	mtspr   MAS7,r10
+	isync
+	msync
+	tlbwe
+#endif
+
 /*
  * Ne need to setup interrupt vector for NAND SPL
  * because NAND SPL never compiles it.
diff --git a/arch/powerpc/include/asm/config_mpc85xx.h b/arch/powerpc/include/asm/config_mpc85xx.h
index 8654625..cf97844 100644
--- a/arch/powerpc/include/asm/config_mpc85xx.h
+++ b/arch/powerpc/include/asm/config_mpc85xx.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2011 Freescale Semiconductor, Inc.
+ * Copyright 2011-2012 Freescale Semiconductor, Inc.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -107,6 +107,7 @@
 #define CONFIG_MAX_CPUS			1
 #define CONFIG_FSL_SDHC_V2_3
 #define CONFIG_SYS_FSL_NUM_LAWS		12
+#define CONFIG_DEBUGGER_TEMP_TLB	3
 #define CONFIG_TSECV2
 #define CONFIG_SYS_FSL_SEC_COMPAT	4
 #define CONFIG_FSL_SATA_V2
-- 
1.7.5.4

[U-Boot] [PATCH 3/4] powerpc/85xx:Update NOR code base to support debugger

[Wolfgang Denk]

Dear Prabhakar Kushwaha,

In message <1329296055-28541-1-git-send-email-prabhakar@freescale.com> you wrote:
> Update the NOR code base to support NOR-boot debugging.
> It ovecome e500 and e500v2's second limitation i.e. IVPR + IVOR15 should be
> valid fetchable OP code address.
> 
> 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.
> 
> Signed-off-by: Radu Lazarescu <radu.lazarescu@freescale.com>
> Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
...
> +	_mas0 = MAS0_TLBSEL(1) |
> +			MAS0_ESEL(CONFIG_DEBUGGER_TEMP_TLB);

You are using an undocumented CONFIG_ option here.

> +++ b/arch/powerpc/cpu/mpc85xx/start.S
> @@ -184,6 +184,48 @@ l2_disabled:
>  	andi.	r1,r3,L1CSR0_DCE at l
>  	beq	2b
>  
> +#if defined(CONFIG_E500_V1_V2) && !defined(CONFIG_SYS_RAMBOOT)

What if no such debug support is needed, and code size hurts?


> @@ -107,6 +107,7 @@
>  #define CONFIG_MAX_CPUS			1
>  #define CONFIG_FSL_SDHC_V2_3
>  #define CONFIG_SYS_FSL_NUM_LAWS		12
> +#define CONFIG_DEBUGGER_TEMP_TLB	3

Undocumented!

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: wd at denx.de
If at first you don't succeed, you are running about average.

[U-Boot] [PATCH 3/4] powerpc/85xx:Update NOR code base to support debugger

[Prabhakar Kushwaha]

Hi Wolfgang,

On Tuesday 06 March 2012 08:15 PM, Wolfgang Denk wrote:
> Dear Prabhakar Kushwaha,
>
> In message<1329296055-28541-1-git-send-email-prabhakar@freescale.com>  you wrote:
>> Update the NOR code base to support NOR-boot debugging.
>> It ovecome e500 and e500v2's second limitation i.e. IVPR + IVOR15 should be
>> valid fetchable OP code address.
>>
>> 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.
>>
>> Signed-off-by: Radu Lazarescu<radu.lazarescu@freescale.com>
>> Signed-off-by: Prabhakar Kushwaha<prabhakar@freescale.com>
> ...
>> +	_mas0 = MAS0_TLBSEL(1) |
>> +			MAS0_ESEL(CONFIG_DEBUGGER_TEMP_TLB);
> You are using an undocumented CONFIG_ option here.

This CONFIG_ is defined as part of documentation patch sent in this series


>> +++ b/arch/powerpc/cpu/mpc85xx/start.S
>> @@ -184,6 +184,48 @@ l2_disabled:
>>   	andi.	r1,r3,L1CSR0_DCE at l
>>   	beq	2b
>>
>> +#if defined(CONFIG_E500_V1_V2)&&  !defined(CONFIG_SYS_RAMBOOT)
> What if no such debug support is needed, and code size hurts?
>

sure it will. I agree with you.
But this piece of code overcome debug restriction of e500 and e500v2 
cores and  I think fixing restriction is a good way to go.


>> @@ -107,6 +107,7 @@
>>   #define CONFIG_MAX_CPUS			1
>>   #define CONFIG_FSL_SDHC_V2_3
>>   #define CONFIG_SYS_FSL_NUM_LAWS		12
>> +#define CONFIG_DEBUGGER_TEMP_TLB	3
> Undocumented!
>
This CONFIG_ is defined as part of documentation patch sent in this series

--Prabhakar

[U-Boot] [PATCH 3/4] powerpc/85xx:Update NOR code base to support debugger

[Wolfgang Denk]

Dear Prabhakar Kushwaha,

In message <4F56DEB0.6060500@freescale.com> you wrote:
> 
> >> +	_mas0 = MAS0_TLBSEL(1) |
> >> +			MAS0_ESEL(CONFIG_DEBUGGER_TEMP_TLB);
> > You are using an undocumented CONFIG_ option here.
> 
> This CONFIG_ is defined as part of documentation patch sent in this series

CONFIG_ options must be documented in the README.

> >> +#if defined(CONFIG_E500_V1_V2)&&  !defined(CONFIG_SYS_RAMBOOT)
> > What if no such debug support is needed, and code size hurts?
> 
> sure it will. I agree with you.
> But this piece of code overcome debug restriction of e500 and e500v2 
> cores and  I think fixing restriction is a good way to go.

What do we do to disable this code if no debug support is needed, and
the code size is considered critical?

> >> +#define CONFIG_DEBUGGER_TEMP_TLB	3
> > Undocumented!
> >
> This CONFIG_ is defined as part of documentation patch sent in this series

This is not sufficient, see above.

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: wd at denx.de
Virtue is a relative term.
	-- Spock, "Friday's Child", stardate 3499.1

[U-Boot] [PATCH 3/4] powerpc/85xx:Update NOR code base to support debugger

[Prabhakar Kushwaha]

Hi Wolfgang,

On Wednesday 07 March 2012 05:35 PM, Wolfgang Denk wrote:
> Dear Prabhakar Kushwaha,
>
> In message<4F56DEB0.6060500@freescale.com>  you wrote:
>>>> +	_mas0 = MAS0_TLBSEL(1) |
>>>> +			MAS0_ESEL(CONFIG_DEBUGGER_TEMP_TLB);
>>> You are using an undocumented CONFIG_ option here.
>> This CONFIG_ is defined as part of documentation patch sent in this series
> CONFIG_ options must be documented in the README.

Sure

>>>> +#if defined(CONFIG_E500_V1_V2)&&   !defined(CONFIG_SYS_RAMBOOT)
>>> What if no such debug support is needed, and code size hurts?
>> sure it will. I agree with you.
>> But this piece of code overcome debug restriction of e500 and e500v2
>> cores and  I think fixing restriction is a good way to go.
> What do we do to disable this code if no debug support is needed, and
> the code size is considered critical?

i will put this piece of code  under #if defined 
(CONFIG_DEBUGGER_TEMP_TLB).
This piece of code will only be enabled when someone wants debugging 
here. And the requirement is temporary TLB.

>>>> +#define CONFIG_DEBUGGER_TEMP_TLB	3
>>> Undocumented!
>>>
>> This CONFIG_ is defined as part of documentation patch sent in this series
> This is not sufficient, see above.

i will add the description.

Regards,
Prabhakar