Cannot flash SPI-NOR MX25U6435F on Odroid N2+

[Christian Kohlschütter]

Some more information:

Apparently, some ODROID-N2+ ship with MX25U6435F, some ship with XT25Q64D SPI-NOR chips.

The ones with XT25Q64D have no problems flashing the first time (using the same kernel / userland). For those chips I see the kernel message "spi-nor spi0.0: found spi-nor-generic, expected mx25u6435f"

I've now tried two boards with MX25U6435F, and they both expose this issue.
(Guessing from the MAC addresses of these boards (00:1e:06:42:b3: vs 00:1e:06:42:fa: in my case), Hardkernel must have changed the MX25U6435F for XT25Q64D in later runs...)

Also, notably, calling flash_erase prior to flashcp doesn't make a difference -- flashcp really wants to be called twice for the MX25U6435F chips ...

> On 24. Mar 2025, at 23:52, Christian Kohlschütter <christian at kohlschutter.com> wrote:
> 
> PS: It seems to work when flashing a second time (i.e., calling flashcp with the same arguments once more).
> 
> Is there a timing requirement between erase and write? Is it a bug in mtd-utils that we just don't hit with the custom 4.9 Odroid kernel?
> 
>> On 24. Mar 2025, at 23:09, Christian Kohlschütter <christian at kohlschutter.com> wrote:
>> 
>> Hi all,
>> 
>> I'm trying to flash the MX25U6435F 8MB SPI-ROM integrated in ODROID N2+ boards.
>> 
>> Using Linux 6.14 (or any other recent mainline kernel), I can't seem to get any changes persisted:
>> 
>> sudo flashcp -v u-boot.spi.bin /dev/mtd0
>> Erasing blocks: 289/289 (100%)
>> Writing data: 1155k/1155k (100%)
>> Verifying data: 10k/1155k (0%)File does not seem to match flash data. First mismatch at 0x00000000-0x00002800
>> 
>> Relevant kernel configs:
>> CONFIG_MTD_SPI_NOR=m
>> CONFIG_MTD_SPI_NOR_SWP_DISABLE=y  # does not make a difference
>> 
>> With the same userland tools (mtd-utils 2.2.1-r0 running on Alpine Linux), flashing succeeds when using their custom kernel (based upon 4.9.337; odroidg12-4.9.y branch from https://github.com/hardkernel/linux)
>> 
>> Note that both kernels need a custom DTB to enable SPI (see ic/meson-g12b-odroid-n2.dtsi).
>> 
>> Linux 6.14 needs these additional entries to meson-g12b-odroid-n2-plus.dts (odroid's 4.9.337 needs similar changes)
>> 
>> &spifc {
>>       status = "okay";
>>       pinctrl-0 = <&nor_pins>;                                           
>>       pinctrl-names = "default";                                         
>> 
>>       mx25u64: flash at 0 {                                  
>>               #address-cells = <1>;
>>               #size-cells = <1>;             
>>               compatible = "mxicy,mx25u6435f", "jedec,spi-nor";
>>               reg = <0>;                                       
>>               spi-max-frequency = <104000000>;                 
>>       };
>> };
>> 
>> &sd_emmc_c {
>>       pinctrl-0 = <&emmc_ctrl_pins>, <&emmc_data_4b_pins>, <&emmc_ds_pins>;
>>       bus-width = <4>;
>> };
>> 
>> Any help pointing me in the right direction is greatly appreciated.
>> 
>> Thanks,
>> Christian
>> 
>