km-powerpc: define CONFIG_PRAM to protect PHRAM and PNVRAM

PATCH New Valentin Longchamp 3 participants 7 messages Jul 17, 2014 – Aug 20, 2014

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Valentin Longchamp

author

2014-07-17 12:24 UTC #0 lore raw

PATCH 1/1 km-powerpc: define CONFIG_PRAM to protect PHRAM and PNVRAM

When u-boot initializes the RAM (early in boot) it looks for the "pram" env variable to know which is area it cannot use.

At this early boot stage, the "pram" env variable is not avaible yet since it gets computed in set_km_env that gets called AFTER the RAM initialization. If the "pram" env variable is not found, the default CONFIG_PRAM value is used.

This value used to 0 (no protection at all). This patch sets it to a value that covers PHRAM and PNVRAM that must be protected in our case.

Signed-off-by Valentin Longchamp <[email protected]>

Signed-off-by Holger Brunck <[email protected]>

---

 include/configs/km/km-powerpc.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

include/configs/km/km-powerpc.h +3 -2

index 763c5ba..eb85a74 100644
@@ -59,8 +59,9 @@
 #define CONFIG_KM_PHRAM		0x100000
 /* resereved pram area at the end of memroy [hex] */
 #define CONFIG_KM_RESERVED_PRAM	0x0
-/* enable protected RAM */
-#define CONFIG_PRAM		0
+/* set the default PRAM value to at least PNVRAM + PHRAM when pram env variable
+ * is not valid yet, which is the case for when u-boot copies itself to RAM */
+#define CONFIG_PRAM		((CONFIG_KM_PNVRAM + CONFIG_KM_PHRAM)>>10)
 
 #define CONFIG_KM_CRAMFS_ADDR	0x800000
 #define CONFIG_KM_KERNEL_ADDR	0x400000	/* 3968Kbytes */

Signature · 1 line

1.8.0.1

Wolfgang Denk

2014-07-17 12:47 UTC #1 lore raw

PATCH 1/1 km-powerpc: define CONFIG_PRAM to protect PHRAM and PNVRAM

Dear Valentin,

Quoted 7 lines · In message <[email protected]>…

When u-boot initializes the RAM (early in boot) it looks for the "pram" env variable to know which is area it cannot use.
At this early boot stage, the "pram" env variable is not avaible yet since it gets computed in set_km_env that gets called AFTER the RAM initialization. If the "pram" env variable is not found, the default CONFIG_PRAM value is used.

Note that I am not objecting against this patch, but I highly recommend to fix your board - RAM initialization is actually pretty late in the init sequence, and you should have a valid envionment long before.

Best regards,

Wolfgang Denk

Signature · 4 lines

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
God may be subtle, but He isn't plain mean.         - Albert Einstein

Valentin Longchamp

author

2014-07-18 09:10 UTC #2 lore raw

PATCH 1/1 km-powerpc: define CONFIG_PRAM to protect PHRAM and PNVRAM

Hello Wolfgang,

Quoted 11 lines · Wolfgang Denk

Dear Valentin,
Quoted 7 lines · In message <[email protected]>…
When u-boot initializes the RAM (early in boot) it looks for the "pram" env variable to know which is area it cannot use.
At this early boot stage, the "pram" env variable is not avaible yet since it gets computed in set_km_env that gets called AFTER the RAM initialization. If the "pram" env variable is not found, the default CONFIG_PRAM value is used.

Quoted 5 lines

Note that I am not objecting against this patch, but I highly recommend to fix your board - RAM initialization is actually pretty late in the init sequence, and you should have a valid envionment long before.

Maybe my commit message is unclear about this. You are right, at the RAM initialization time, there is a valid environment, and that's the case on our board too.

However, at the very first boot on a board, the environment is empty (or unvalid) and the default one is used where this "pram" env variable is not defined. That's why the CONFIG_PRAM is used in this case and it should be defined. This is not going to be the case at any later boot if a valid environment (with pram defined) is found and used.

Best regards,

Valentin

York Sun

2014-08-12 18:03 UTC #3 lore raw

PATCH 1/1 km-powerpc: define CONFIG_PRAM to protect PHRAM and PNVRAM

Quoted 24 lines · Valentin Longchamp

Hello Wolfgang,
Quoted 11 lines · Wolfgang Denk
Dear Valentin,
Quoted 7 lines · In message <[email protected]>…
When u-boot initializes the RAM (early in boot) it looks for the "pram" env variable to know which is area it cannot use.
At this early boot stage, the "pram" env variable is not avaible yet since it gets computed in set_km_env that gets called AFTER the RAM initialization. If the "pram" env variable is not found, the default CONFIG_PRAM value is used.
Quoted 5 lines
Note that I am not objecting against this patch, but I highly recommend to fix your board - RAM initialization is actually pretty late in the init sequence, and you should have a valid envionment long before.
Maybe my commit message is unclear about this. You are right, at the RAM initialization time, there is a valid environment, and that's the case on our board too.

Quoted 8 lines

However, at the very first boot on a board, the environment is empty (or unvalid) and the default one is used where this "pram" env variable is not defined. That's why the CONFIG_PRAM is used in this case and it should be defined. This is not going to be the case at any later boot if a valid environment (with pram defined) is found and used.
Best regards,

Valentin,

How about you update the commit message to
explain you are defining the default CONFIG_PRAM for your board in case "pram" variable is not available?

York

Valentin Longchamp

author

2014-08-13 06:13 UTC #4 lore raw

PATCH 1/1 km-powerpc: define CONFIG_PRAM to protect PHRAM and PNVRAM

Hi York,

Quoted 35 lines · York Sun

Quoted 24 lines · Valentin Longchamp
Hello Wolfgang,
Quoted 11 lines · Wolfgang Denk
Dear Valentin,
Quoted 7 lines · In message <[email protected]>…
When u-boot initializes the RAM (early in boot) it looks for the "pram" env variable to know which is area it cannot use.
At this early boot stage, the "pram" env variable is not avaible yet since it gets computed in set_km_env that gets called AFTER the RAM initialization. If the "pram" env variable is not found, the default CONFIG_PRAM value is used.
Quoted 5 lines
Note that I am not objecting against this patch, but I highly recommend to fix your board - RAM initialization is actually pretty late in the init sequence, and you should have a valid envionment long before.
Maybe my commit message is unclear about this. You are right, at the RAM initialization time, there is a valid environment, and that's the case on our board too.
Quoted 8 lines
However, at the very first boot on a board, the environment is empty (or unvalid) and the default one is used where this "pram" env variable is not defined. That's why the CONFIG_PRAM is used in this case and it should be defined. This is not going to be the case at any later boot if a valid environment (with pram defined) is found and used.
Best regards,

Quoted 6 lines

Valentin,
How about you update the commit message to
explain you are defining the default CONFIG_PRAM for your board in case "pram" variable is not available?

OK, I will do ... even though the commit message already does already state that, just with more details when and why (there was just a missing precision here, "when no valid environment was found") the "pram" env variable can be undefined and why it is important for us to have such a value. But maybe that's too much information ?

Valentin

Valentin Longchamp

author

2014-08-13 08:24 UTC #5 lore raw

PATCH v2 1/1 km-powerpc: define CONFIG_PRAM to protect PHRAM and PNVRAM

In reply to Valentin Longchamp

When u-boot initializes the RAM (early in boot) it looks for the "pram" env variable to know which is area it cannot use. If the "pram" env variable is not found, the default CONFIG_PRAM value is used.

This value used to be 0 (no protection at all). This patch sets it to a value that covers PHRAM and PNVRAM that must be protected in our case.

Signed-off-by Valentin Longchamp <[email protected]>

Signed-off-by Holger Brunck <[email protected]>

---

Changes in v2:
- simplify the commit message for more clarity.

 include/configs/km/km-powerpc.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

include/configs/km/km-powerpc.h +3 -2

index 763c5ba..eb85a74 100644
@@ -59,8 +59,9 @@
 #define CONFIG_KM_PHRAM		0x100000
 /* resereved pram area at the end of memroy [hex] */
 #define CONFIG_KM_RESERVED_PRAM	0x0
-/* enable protected RAM */
-#define CONFIG_PRAM		0
+/* set the default PRAM value to at least PNVRAM + PHRAM when pram env variable
+ * is not valid yet, which is the case for when u-boot copies itself to RAM */
+#define CONFIG_PRAM		((CONFIG_KM_PNVRAM + CONFIG_KM_PHRAM)>>10)
 
 #define CONFIG_KM_CRAMFS_ADDR	0x800000
 #define CONFIG_KM_KERNEL_ADDR	0x400000	/* 3968Kbytes */

Signature · 1 line

1.8.0.1

York Sun

2014-08-20 19:38 UTC #6 lore raw

PATCH v2 1/1 km-powerpc: define CONFIG_PRAM to protect PHRAM and PNVRAM

Quoted 7 lines · Valentin Longchamp

When u-boot initializes the RAM (early in boot) it looks for the "pram" env variable to know which is area it cannot use. If the "pram" env variable is not found, the default CONFIG_PRAM value is used.
This value used to be 0 (no protection at all). This patch sets it to a value that covers PHRAM and PNVRAM that must be protected in our case.

Quoted 7 lines

Signed-off-by Valentin Longchamp <[email protected]>
Signed-off-by Holger Brunck <[email protected]>
---
Changes in v2:
- simplify the commit message for more clarity.

Applied to u-boot-mpc85xx master branch, awaiting for upstream.

York