[U-Boot] [PATCH v2] Add support for KMC KZM-ARM11-01 board
Atsuo Igarashi
atsuo_igarashi at tripeaks.co.jp
Thu Sep 18 08:06:27 CEST 2008
Dear Wolfgang Denk,
>>> +/*
>>> + * The MX31ADS board seems to have a hardware "peculiarity"
>>> confirmed under
>>> + * U-Boot, RedBoot and Linux: the ethernet Rx signal is reaching the
>>> CS8900A
>>> + * controller inverted. The controller is capable of detecting and
>>> correcting
>>> + * this, but it needs 4 network packets for that. Which means, at
>>> startup, you
>>> + * will not receive answers to the first 4 packest, unless there
>>> have been some
>>> + * broadcasts on the network, or your board is on a hub. Reducing
>>> the ARP
>>> + * timeout from default 5 seconds to 200ms we speed up the initial TFTP
>>> + * transfer, should the user wish one, significantly.
>>> + */
>>> +#define CONFIG_ARP_TIMEOUT 200UL
>>
>>
>> Is this really needed on your hardware, too? I doubt it.
>>
>
> Probably, this is not needed.
> I'll remove this.
>
In our board which has SMC9118 controller, it seems that it needs a few hundred
milliseconds wait after the initialization. So this is needed.
I'll modify only these comment.
>>> +/* Address and size of Redundant Environment Sector */
>>> +#define CFG_ENV_OFFSET_REDUND (CFG_ENV_OFFSET + CFG_ENV_SIZE)
>>> +#define CFG_ENV_SIZE_REDUND CFG_ENV_SIZE
>>> +
>>> +/* S29WS256N NOR flash has 4 32KiB small sectors at the beginning
>>> and at the end.
>>> + * The rest of 32MiB is in 128KiB big sectors. U-Boot occupies the
>>> low 4 sectors,
>>> + * if we put environment next to it, we will have to occupy 128KiB
>>> for it.
>>> + * Putting it at the top of flash we use only 32KiB. */
>>> +#define CFG_ENV_ADDR (CFG_MONITOR_BASE + CFG_ENV_SECT_SIZE)
>>
>> This is a very ugly set up, because you split the U-Boot related
>> informatiomn, and you block both ends of your flash memory. Why don;t
>> you locate the environment for example in the third and fourts
>> sectors, i. e. use such a setup (called "embedded environment"):
>>
>> sector 1: 32 KiB - U-Boot code
>> sector 2: 32 KiB - more U-Boot code
>> sector 3: 32 KiB - environment, first copy
>> sector 4: 32 KiB - environment, second (redundant) copy
>> sector 5: 128 KiB - more U-Boot code
>> ...
>>
>> ?
>
> Indeed. I think so too.
> I'll rework.
>
In our board which has S29GL512N NOR flash, it has 512 128KiB big sector only.
So I leave this, and I'll modify only these comment.
sector 1: 128 KiB - U-Boot code
sector 2: 128 KiB - environment, first copy
sector 3: 128 KiB - environment, second (redundant) copy
sector 4: 128 KiB - more U-Boot code
Regards,
Atsuo Igarashi
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