Hi,
On 25/09/19 4:37 PM, Simon Goldschmidt wrote:
> On Tue, Sep 24, 2019 at 2:08 PM Simon Goldschmidt
> <simon.k.r.goldschm...@gmail.com> wrote:
>>
[...]
>>>
>>> But, do you have access to n25q variants? And does that support 4 Byte
>>> addressing opcode? What does its JEDEC ID read?
>>
>> No, at the moment I don't. I'll see if I can get hold of one.
>
> Ok, so I found a board with an n25q256a and tested that as well as the
> Altera/Intel EPCQ256N (on socfpga_socrateds) and both read the same ID and
> SFDP:
>
> JEDEC id bytes: 20, ba, 19, 10, 00, 00
> bfpt.dwords[0] = fffb20e5
> bfpt.dwords[1] = 0fffffff
> bfpt.dwords[2] = 6b27eb29
> bfpt.dwords[3] = bb273b08
> bfpt.dwords[4] = ffffffff
> bfpt.dwords[5] = bb27ffff
> bfpt.dwords[6] = eb29ffff
> bfpt.dwords[7] = d810200c
> bfpt.dwords[8] = 00000000
> bfpt.dwords[9] = 00000000
> bfpt.dwords[10] = 00000000
> bfpt.dwords[11] = 00000000
> bfpt.dwords[12] = 00000000
> bfpt.dwords[13] = 00000000
> bfpt.dwords[14] = 00000000
> bfpt.dwords[15] = 00000000
> SF: Detected n25q256a with page size 256 Bytes, erase size 64 KiB, total 32
> MiB
>
Thanks for the logs!
> I don't know whether one of these supports 4 byte opcodes, but I guess it's
> safe to say the 5th byte 0x44 is an mt25 which supports 4 byte opcodes.
>
There is a way to test if flash supports 4 byte addressing opcodes:
With plain U-Boot master (without any of my patches) that has SPI_NOR_4B_OPCODES
set for n25q256a try following:
sf erase 0x0 0x10000 /* erase one sector at 0x0 */
sf erase 0x1000000 0x1000 /* erase one sector at 16M */
sf write <address of random data> 0x1000000 0x100 /* write a page of
data at 16M */
sf read addr1 0x1000000 0x100 /* read back */
md.b addr1
In case flash does not understand 4 byte addressing opcode, its possible
that data written to flash may wrap and be written to 0x0-0x10000.
So readback and see if 0x0 is still all 0xffs:
sf read addr1 0x0 0x100
md.b addr1
So if first md.b shows valid data and second md.b shows all 0xffs then flash
supports 4 byte addressing opcode
Regards
Vignesh
> Do you plan to port this series to Linux, too?
>
> Regards,
> Simon
>
>>
>> Regards,
>> Simon
>>
>>>
>>>> I also wasn't really aware of the differences between those two, sorry.
>>>>
>>>> Regards,
>>>> Simon
>>>>
>>>>>
>>>>> Cheers,
>>>>> ta
>>>>>
--
Regards
Vignesh
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
https://lists.denx.de/listinfo/u-boot
