QSPI NOR Flash
The phyCORE-AM57x SOM can incorporate a 16MB NOR Flash, serving either as volatile or non-volatile memory. Opting for an SPI Flash can obviate the necessity of installing NAND Flash or eMMC memory on the SOM. This approach is particularly beneficial for applications demanding a compact code footprint or utilizing a small Real-Time Operating System (RTOS). The NOR device is linked to the qspi1 interface.
This guide furnishes instructions on interfacing with the NOR Flash from Linux. For additional details regarding the phyCORE-AM57x QSPI NOR memory, please refer to section 6.5 in the Hardware Manual.
Note
The standard development kit offering does not include a SOM with the NOR Flash populated and the QSPI interface is disabled by default. See the Release Notes for more information. For further support, please visit PHYTEC’s Support Portal.
Setup and Partition Information
Reference the following kernel diff to help you modify the default BSP, the QSPI interface must be enabled.
Kernel Patchdiff --git a/arch/arm/boot/dts/am5728-pcm-057-40300111i.dtsi b/arch/arm/boot/dts/am5728-pcm-057-40300111i.dtsi index 2fef05af1043..64cab5ac7169 100644 --- a/arch/arm/boot/dts/am5728-pcm-057-40300111i.dtsi +++ b/arch/arm/boot/dts/am5728-pcm-057-40300111i.dtsi @@ -28,15 +28,15 @@ }; &qspi { - status = "disabled"; + status = "okay"; }; &qspi_nor { - status = "disabled"; + status = "okay"; }; &qspi_nor_cs0 { - status = "disabled"; + status = "okay"; }; &i2c_rtc {In order to apply the changes, referred to by the diff above, to your local kernel source first follow the Build the BSP guide and then reference the Modify The BSP guide.
Once you have a updated device tree blob, copy this to your bootable SD Card:
Target (Linux)cd ~/Downloads cp am5728-phycore-kit-41300111i-NOR.dtb /media/<user>/rootfs/boot/
Safely remove the SD Card from your Host Machine.
Configure the development kit to boot from SD Card. Reference the SD Card guide for more information.
Insert the SD Card into the phyCORE-AM57x development kit and power it on.
Stop in U-Boot when prompted.
Enter the following in U-Boot to specify which device tree will be used during Linux bring-up:
Target (U-Boot)setenv board_name undefined setenv fdtfile am5728-phycore-kit-41300111i-NOR.dtb saveenv boot
Tip
It is necessary to change the board_name variable to “undefined” so that U-Boot doesn’t automatically source the original device tree with QSPI disabled. For more information, see the Configuring the Bootloader guide.
Lets take a look at the flash memory to see what software defined partitions are available:
Target (Linux)mtdinfo -a
Example Outputroot@am57xx-phycore-kit:~# mtdinfo -a Count of MTD devices: 7 Present MTD devices: mtd0, mtd1, mtd2, mtd3, mtd4, mtd5, mtd6 Sysfs interface supported: yes mtd0 Name: QSPI.SPL Type: nor Eraseblock size: 65536 bytes, 64.0 KiB Amount of eraseblocks: 4 (262144 bytes, 256.0 KiB) Minimum input/output unit size: 1 byte Sub-page size: 1 byte Character device major/minor: 90:0 Bad blocks are allowed: false Device is writable: true mtd1 Name: QSPI.u-boot Type: nor Eraseblock size: 65536 bytes, 64.0 KiB Amount of eraseblocks: 16 (1048576 bytes, 1024.0 KiB) Minimum input/output unit size: 1 byte Sub-page size: 1 byte Character device major/minor: 90:2 Bad blocks are allowed: false Device is writable: true mtd2 Name: QSPI.u-boot-spl-os Type: nor Eraseblock size: 65536 bytes, 64.0 KiB Amount of eraseblocks: 8 (524288 bytes, 512.0 KiB) Minimum input/output unit size: 1 byte Sub-page size: 1 byte Character device major/minor: 90:4 Bad blocks are allowed: false Device is writable: true mtd3 Name: QSPI.u-boot-env Type: nor Eraseblock size: 65536 bytes, 64.0 KiB Amount of eraseblocks: 1 (65536 bytes, 64.0 KiB) Minimum input/output unit size: 1 byte Sub-page size: 1 byte Character device major/minor: 90:6 Bad blocks are allowed: false Device is writable: true mtd4 Name: QSPI.u-boot-env.backup1 Type: nor Eraseblock size: 65536 bytes, 64.0 KiB Amount of eraseblocks: 1 (65536 bytes, 64.0 KiB) Minimum input/output unit size: 1 byte Sub-page size: 1 byte Character device major/minor: 90:8 Bad blocks are allowed: false Device is writable: true mtd5 Name: QSPI.kernel Type: nor Eraseblock size: 65536 bytes, 64.0 KiB Amount of eraseblocks: 128 (8388608 bytes, 8.0 MiB) Minimum input/output unit size: 1 byte Sub-page size: 1 byte Character device major/minor: 90:10 Bad blocks are allowed: false Device is writable: true mtd6 Name: QSPI.file-system Type: nor Eraseblock size: 65536 bytes, 64.0 KiB Amount of eraseblocks: 98 (6422528 bytes, 6.1 MiB) Minimum input/output unit size: 1 byte Sub-page size: 1 byte Character device major/minor: 90:12 Bad blocks are allowed: false Device is writable: true
We can see that this device tree defines 7 partitions for our NOR Flash.
Write to QSPI
Create a file that will fit into a partition (we are going to use the last partition, mtd6):
Target (Linux)dd if=/dev/urandom of=/tmp/test.dat bs=64k count=98
Note that the size of a partition is a multiple of the erase block size!
Write the file to the partition:
Target (Linux)flashcp -v /tmp/test.dat /dev/mtd6
Example Outputroot@am57xx-phycore-kit:~# dd if=/dev/urandom of=/tmp/test.dat bs=64k count=98 98+0 records in 98+0 records out root@am57xx-phycore-kit:~# flashcp -v /tmp/test.dat /dev/mtd6 Erasing blocks: 98/98 (100%) Writing data: 6272k/6272k (100%) Verifying data: 6272k/6272k (100%)
Read from QSPI
Read back the file we just wrote:
Target (Linux)dd if=/dev/mtd6 of=/tmp/qspi_read.dat bs=64k count=98
Lets compare the two files to ensure that what was read is the same as what was written:
Target (Linux)md5sum /tmp/qspi_read.dat && md5sum /tmp/test.dat
Example Outputroot@am57xx-phycore-kit:~# dd if=/dev/mtd6 of=/tmp/qspi_read.dat bs=64k count=98 98+0 records in 98+0 records out root@am57xx-phycore-kit:~# md5sum /tmp/qspi_read.dat && md5sum /tmp/test.dat dd83dcf5d8b7cbbfebdf012381e42f7a /tmp/qspi_read.dat dd83dcf5d8b7cbbfebdf012381e42f7a /tmp/test.dat