AM625: Linux SDK : SPL and u-boot questions

Koichiro Tashiro

Part Number: AM625

Tool/software:

Hi,

My customer has below questions for Linux SDK v.10.01.10.04.
QSPI-NAND flash booting is considered.

Q1) Which SPL(Secondary Program Loader) is used?
Q2) SPL source codes are available?
Q3) Does SPL use MTD(Memory Technology Device) to access NAND Flash?
If not, the customer wants to know how SPL accesses to NAND.
Q4) Does u-boot use MTD(Memory Technology Device) to access NAND Flash?
If not, the customer wants to know how u-boot accesses to NAND.

Thanks and regards,
Koichiro Tashiro

7 months ago

0 Mukul Bhatnagar 7 months ago

TI__Guru* 84375 points

I am assigning this thread Andreas, but please note he is out of office this week. responses will be delayed.

0 Vaibhav Kumar 7 months ago

TI__Mastermind 47426 points

Hi,

Thanks for your query.

I am going to share with you few references which might help you move forward.

Reference 1: https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/10_01_10_04/exports/docs/linux/Foundational_Components/Kernel/Kernel_Drivers/Storage/NAND.html

Reference 2: https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/10_01_10_04/exports/docs/linux/Foundational_Components/U-Boot/UG-QSPI.html

Reference 3: https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/10_01_10_04/exports/docs/linux/Foundational_Components/Kernel/Kernel_Drivers/QSPI.html

Let me know if this helps the customer.

Looking forward to your response.

Regards,

Vaibhav

0 Koichiro Tashiro 7 months ago in reply to Vaibhav Kumar

TI__Mastermind 22945 points

Hi Mukul, Vaibhav,

I looked these references, but I could not find answers to these questions.
It seems most of the information is Linux kernel driver. The customer is asking before Linux kernel start-up.
I will wait for answers from Andreas.

Thanks and regards,
Koichiro Tashiro

0 Andreas Dannenberg 7 months ago in reply to Koichiro Tashiro

TI__Guru 69867 points

Tashiro-san,

Koichiro Tashiro said:
I will wait for answers from Andreas.

this just got assigned to me. I'm on PTO this week, but will look into this next week when I'm back in the office.,

Regards, Andreas

0 Koichiro Tashiro 6 months ago in reply to Andreas Dannenberg

TI__Mastermind 22945 points

Hi Andreas,

Do you have any updates to this item?

Thanks and regards,
Koichiro Tashiro

0 Andreas Dannenberg 6 months ago

TI__Guru 69867 points

Hi Tashiro-san,

Koichiro Tashiro said:
Q1) Which SPL(Secondary Program Loader) is used?

U-Boot SPL is the default SPL of our Linux SDK. Component version is per SDK Release notes here: https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/10_01_10_04/exports/docs/devices/AM62X/linux/Release_Specific_Release_Notes.html#u-boot

Koichiro Tashiro said:
Q2) SPL source codes are available?

See above, the release notes describe how to obtain/access that exact version. Here's the direct link to the specific source snapshot: https://git.ti.com/cgit/ti-u-boot/ti-u-boot/log/?h=10.01.10

Koichiro Tashiro said:
Q3) Does SPL use MTD(Memory Technology Device) to access NAND Flash?
If not, the customer wants to know how SPL accesses to NAND.

Yes it does use MTD drivers/technology, if enabled via appropriate CONFIG_SPL_* config options. Note that our default U-Boot SPL defconfig file configs/am62x_evm_r5_defconfig for the AM62x Linux SDK does not enable NAND or MTD support, as the associated development board comes with an OSPI NOR flash, not a NAND flash. However one can look at a defconfig file from a device that is associated with a board that has an OSPI NAND flash on it, like configs/am62ax_evm_r5_defconfig, and model/integrate NAND support accordingly over to AM62x. Having a quick look, the following config options will be relevant:

[for U-Boot SPL]

> CONFIG_SPL_MTD_LOAD=y
> CONFIG_SPL_MTD=y
> CONFIG_SPL_NAND_SPI_SUPPORT=y

[for U-Boot]

> CONFIG_DM_MTD=y
> CONFIG_MTD_SPI_NAND=y

Koichiro Tashiro said:
Q4) Does u-boot use MTD(Memory Technology Device) to access NAND Flash?

Yes, same as U-Boot SPL. And in U-Boot there is also a command available (called `mtd`) that can be used to read/write the NAND Flash, see https://software-dl.ti.com/processor-sdk-linux/esd/AM62AX/10_01_00/exports/docs/linux/Foundational_Components/U-Boot/UG-QSPI.html#ospi-qspi-nor-nand

Regards, Andreas

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AM625: Linux SDK : SPL and u-boot questions