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.goldschmidt@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