[U-Boot] [PATCH] 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 valentin.longchamp@keymile.com Signed-off-by: Holger Brunck holger.brunck@keymile.com ---
include/configs/km/km-powerpc.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/configs/km/km-powerpc.h b/include/configs/km/km-powerpc.h index 763c5ba..eb85a74 100644 --- a/include/configs/km/km-powerpc.h +++ b/include/configs/km/km-powerpc.h @@ -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 */
Dear Valentin,
In message 1405599840-11984-1-git-send-email-valentin.longchamp@keymile.com you wrote:
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
Hello Wolfgang,
On 07/17/2014 02:47 PM, Wolfgang Denk wrote:
Dear Valentin,
In message 1405599840-11984-1-git-send-email-valentin.longchamp@keymile.com you wrote:
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.
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
On 07/18/2014 02:10 AM, Valentin Longchamp wrote:
Hello Wolfgang,
On 07/17/2014 02:47 PM, Wolfgang Denk wrote:
Dear Valentin,
In message 1405599840-11984-1-git-send-email-valentin.longchamp@keymile.com you wrote:
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.
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,
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
Hi York,
On 08/12/2014 08:03 PM, York Sun wrote:
On 07/18/2014 02:10 AM, Valentin Longchamp wrote:
Hello Wolfgang,
On 07/17/2014 02:47 PM, Wolfgang Denk wrote:
Dear Valentin,
In message 1405599840-11984-1-git-send-email-valentin.longchamp@keymile.com you wrote:
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.
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,
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
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 valentin.longchamp@keymile.com Signed-off-by: Holger Brunck holger.brunck@keymile.com
---
Changes in v2: - simplify the commit message for more clarity.
include/configs/km/km-powerpc.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/configs/km/km-powerpc.h b/include/configs/km/km-powerpc.h index 763c5ba..eb85a74 100644 --- a/include/configs/km/km-powerpc.h +++ b/include/configs/km/km-powerpc.h @@ -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 */
On 08/13/2014 01:24 AM, Valentin Longchamp wrote:
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 valentin.longchamp@keymile.com Signed-off-by: Holger Brunck holger.brunck@keymile.com
Changes in v2:
- simplify the commit message for more clarity.
Applied to u-boot-mpc85xx master branch, awaiting for upstream.
York
participants (3)
-
Valentin Longchamp -
Wolfgang Denk -
York Sun