diff mbox

[U-Boot,PATCHv2] omap3evm: Pass 'mem' argument to linux kernel

Message ID 1317135653-13435-1-git-send-email-premi@ti.com
State Changes Requested
Headers show

Commit Message

Sanjeev Premi Sept. 27, 2011, 3 p.m. UTC
In absence of this argument, Linux kernel doesn't boot.

Even though many newer boards support 256M, default
value has been set to 128M to ensure that default
build can boot older EVM variants.

Signed-off-by: Sanjeev Premi <premi@ti.com>
---
 Changes since v1:
  Removed the string terminators "\0" from
  definition of mmcargs and nandargs.

 include/configs/omap3_evm.h |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

Comments

Tom Rini Sept. 27, 2011, 3:58 p.m. UTC | #1
On Tue, Sep 27, 2011 at 8:00 AM, Sanjeev Premi <premi@ti.com> wrote:
> In absence of this argument, Linux kernel doesn't boot.
>
> Even though many newer boards support 256M, default
> value has been set to 128M to ensure that default
> build can boot older EVM variants.
>
> Signed-off-by: Sanjeev Premi <premi@ti.com>

But you aren't addressing the fact you just limited everyone to 128M,
which is not right.  Please make this set the value to what u-boot
detects the board to have at runtime at least.
Sanjeev Premi Sept. 27, 2011, 4:43 p.m. UTC | #2
> -----Original Message-----
> From: Tom Rini [mailto:tom.rini@gmail.com] 
> Sent: Tuesday, September 27, 2011 9:29 PM
> To: Premi, Sanjeev
> Cc: u-boot@lists.denx.de
> Subject: Re: [U-Boot] [PATCHv2] omap3evm: Pass 'mem' argument 
> to linux kernel
> 
> On Tue, Sep 27, 2011 at 8:00 AM, Sanjeev Premi <premi@ti.com> wrote:
> > In absence of this argument, Linux kernel doesn't boot.
> >
> > Even though many newer boards support 256M, default
> > value has been set to 128M to ensure that default
> > build can boot older EVM variants.
> >
> > Signed-off-by: Sanjeev Premi <premi@ti.com>
> 
> But you aren't addressing the fact you just limited everyone to 128M,
> which is not right.  Please make this set the value to what u-boot
> detects the board to have at runtime at least.

This patch changes the static environment string compiled
on the host.

These is the default value that gets the board booting up.
The environment variable memsize can be overwritten to 256M
by the boards that have more memory. So, there is no hard
limit.

...which I believe is better than kernel failing to load on old
boards; leaving some users clueless about failure.

Detecting the actual memory size and then changing the environment
variable can be a feature, but it isn't fool proof, because many
applications esp on DM3730, use memory hole and would like their
bootargs to be different.

~sanjeev

> 
> -- 
> Tom
>
Tom Rini Sept. 27, 2011, 7:29 p.m. UTC | #3
On Tue, Sep 27, 2011 at 9:43 AM, Premi, Sanjeev <premi@ti.com> wrote:
>> -----Original Message-----
>> From: Tom Rini [mailto:tom.rini@gmail.com]
>> Sent: Tuesday, September 27, 2011 9:29 PM
>> To: Premi, Sanjeev
>> Cc: u-boot@lists.denx.de
>> Subject: Re: [U-Boot] [PATCHv2] omap3evm: Pass 'mem' argument
>> to linux kernel
>>
>> On Tue, Sep 27, 2011 at 8:00 AM, Sanjeev Premi <premi@ti.com> wrote:
>> > In absence of this argument, Linux kernel doesn't boot.
>> >
>> > Even though many newer boards support 256M, default
>> > value has been set to 128M to ensure that default
>> > build can boot older EVM variants.
>> >
>> > Signed-off-by: Sanjeev Premi <premi@ti.com>
>>
>> But you aren't addressing the fact you just limited everyone to 128M,
>> which is not right.  Please make this set the value to what u-boot
>> detects the board to have at runtime at least.
>
> This patch changes the static environment string compiled
> on the host.
>
> These is the default value that gets the board booting up.
> The environment variable memsize can be overwritten to 256M
> by the boards that have more memory. So, there is no hard
> limit.
>
> ...which I believe is better than kernel failing to load on old
> boards; leaving some users clueless about failure.
>
> Detecting the actual memory size and then changing the environment
> variable can be a feature, but it isn't fool proof, because many
> applications esp on DM3730, use memory hole and would like their
> bootargs to be different.

Thanks for explaining.  Given that someone else objected to this on
the same grounds against v1 please try and add that type of info to
the email in the future.
Sanjeev Premi Sept. 27, 2011, 8:15 p.m. UTC | #4
>From: Tom Rini [tom.rini@gmail.com]
>Sent: Wednesday, September 28, 2011 12:59 AM
>To: Premi, Sanjeev
>Cc: u-boot@lists.denx.de
>Subject: Re: [U-Boot] [PATCHv2] omap3evm: Pass 'mem' argument to linux kernel
>
>On Tue, Sep 27, 2011 at 9:43 AM, Premi, Sanjeev <premi@ti.com> wrote:
>>> -----Original Message-----
>>> From: Tom Rini [mailto:tom.rini@gmail.com]
>>> Sent: Tuesday, September 27, 2011 9:29 PM
>>> To: Premi, Sanjeev
>>> Cc: u-boot@lists.denx.de
>>> Subject: Re: [U-Boot] [PATCHv2] omap3evm: Pass 'mem' argument
>>> to linux kernel
>>>
>>> On Tue, Sep 27, 2011 at 8:00 AM, Sanjeev Premi <premi@ti.com> wrote:
>>> > In absence of this argument, Linux kernel doesn't boot.
>>> >
>>> > Even though many newer boards support 256M, default
>>> > value has been set to 128M to ensure that default
>>> > build can boot older EVM variants.
>>> >
>>> > Signed-off-by: Sanjeev Premi <premi@ti.com>
>>>
>>> But you aren't addressing the fact you just limited everyone to 128M,
>>> which is not right.  Please make this set the value to what u-boot
>>> detects the board to have at runtime at least.
>>
>> This patch changes the static environment string compiled
>> on the host.
>>
>> These is the default value that gets the board booting up.
>> The environment variable memsize can be overwritten to 256M
>> by the boards that have more memory. So, there is no hard
>> limit.
>>
>> ...which I believe is better than kernel failing to load on old
>> boards; leaving some users clueless about failure.
>>
>> Detecting the actual memory size and then changing the environment
>> variable can be a feature, but it isn't fool proof, because many
>> applications esp on DM3730, use memory hole and would like their
>> bootargs to be different.
>
>Thanks for explaining.  Given that someone else objected to this on
>the same grounds against v1 please try and add that type of info to
>the email in the future.

I did miss the mail from Igor, and responded to him later. The patch
describes the reason for choosing 128M - which i considered sufficient.
It didn't occur to me that changes to CONFIG_BOOTARGS could/ would be
considered as hard limit - else I would have described.

~sanjeev

>
>--
>Tom
>
Wolfgang Denk Sept. 28, 2011, 6:57 p.m. UTC | #5
Dear Sanjeev Premi,

In message <1317135653-13435-1-git-send-email-premi@ti.com> you wrote:
> In absence of this argument, Linux kernel doesn't boot.
> 
> Even though many newer boards support 256M, default
> value has been set to 128M to ensure that default
> build can boot older EVM variants.
> 
> Signed-off-by: Sanjeev Premi <premi@ti.com>
> ---
>  Changes since v1:
>   Removed the string terminators "\0" from
>   definition of mmcargs and nandargs.
> 
>  include/configs/omap3_evm.h |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)

My questions remain:  why cannot we simple remove these mem+ settings
which cause only harm?

Best regards,

Wolfgang Denk
Wolfgang Denk Sept. 28, 2011, 6:59 p.m. UTC | #6
Dear "Premi, Sanjeev",

In message <B85A65D85D7EB246BE421B3FB0FBB59302577A8A4D@dbde02.ent.ti.com> you wrote:
>
> These is the default value that gets the board booting up.
> The environment variable memsize can be overwritten to 256M
> by the boards that have more memory. So, there is no hard
> limit.

Why the hell would you ever want to do that?  U-Boot is capable of
auto-detecting the actual RAM sioze and passing correct information to
Linux, so why do you meddle with this?

Best regards,

Wolfgang Denk
diff mbox

Patch

diff --git a/include/configs/omap3_evm.h b/include/configs/omap3_evm.h
index 7af30c2..c399515 100644
--- a/include/configs/omap3_evm.h
+++ b/include/configs/omap3_evm.h
@@ -200,11 +200,14 @@ 
 	"loadaddr=0x82000000\0" \
 	"usbtty=cdc_acm\0" \
 	"mmcdev=0\0" \
+	"memsize=128M\0" \
 	"console=ttyO0,115200n8\0" \
 	"mmcargs=setenv bootargs console=${console} " \
+		"mem=${memsize} " \
 		"root=/dev/mmcblk0p2 rw " \
 		"rootfstype=ext3 rootwait\0" \
 	"nandargs=setenv bootargs console=${console} " \
+		"mem=${memsize} " \
 		"root=/dev/mtdblock4 rw " \
 		"rootfstype=jffs2\0" \
 	"loadbootscript=fatload mmc ${mmcdev} ${loadaddr} boot.scr\0" \