topic Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3 in Processor Expert Software

Linux Kernel does not start after migrating from LPDDR2 to DDR3

steffendoster — Wed, 14 Apr 2021 09:55:45 GMT

Hello everyone,

I have a custom i.MX6DL board running with mainline U-Boot and Linux-Kernel.

Now I have migrated from LPDDR2 to DDR3 and also increased the RAM-Size from 512MB to 1GB, thats all. The rest of the board is still identical.
I have managed to get the DDR3 running in U-Boot. I can start a netboot, can access USB, eMMC .....
Everything works fin there.

BUT: If I try to start my linux-kernel, everything I see is:

DHCP client bound to address 172.16.2.75 (255 ms) Using FEC device TFTP from server 172.16.0.72; our IP address is 172.16.2.75 Filename 'Board/board.dtb'. Load address: 0x18000000 Loading: ### 1.9 MiB/s done Bytes transferred = 30295 (7657 hex) BOOTP broadcast 1 DHCP client bound to address 172.16.2.75 (4 ms) Using FEC device TFTP from server 172.16.0.72; our IP address is 172.16.2.75 Filename 'Board/linuximage'. Load address: 0x12000000 Loading: ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################## 3.8 MiB/s done Bytes transferred = 7167880 (6d5f88 hex) Kernel image @ 0x12000000 [ 0x000000 - 0x6d5f88 ] ## Flattened Device Tree blob at 18000000 Booting using the fdt blob at 0x18000000 Loading Device Tree to 4f58c000, end 4f596656 ... OK Starting kernel ...

It seems that there is something running, but I don't know where to go from here.

Any ideas or suggestions?

More informations needed?

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

igorpadykov — Thu, 15 Apr 2021 00:18:19 GMT

Hi Steffen

first recommended to run ddr test (also use Script Aid)

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/i-MX-6-7-DDR-Stress-Test-Tool/ta-p/1108221

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/i-MX6ULL-LPDDR2-Script-Aid/ta-p/1121785

then update uboot dcd header with new ddr settings found from test

https://source.codeaurora.org/external/imx/uboot-imx/tree/board/freescale/mx6sabresd/mx6dlsabresd.cfg?h=imx_v2020.04_5.4.70_2.3.0

Best regards
igor

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

steffendoster — Thu, 15 Apr 2021 06:31:42 GMT

Hello Igor,

sorry, had forgot to mention that I already did that.
Script aid and resulting U-Boot-CFG is attached (U-Boot-CFG renamed to .txt because .cfg is not allowed here).

The DDR-Stresstester results looks fine. I ran a test for frequencies ranging from 350MHz to 500MHz and the first errors were shown at 475MHz.
(By the way: how can the Stress-Tester test frequencies above 400MHz when i.MX6DL only supports 400MHz?)

I tested also with mtest of u-boot and no errors occured.

Thanks for the fast reply.

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

igorpadykov — Thu, 15 Apr 2021 10:35:09 GMT

Hi Steffen

please try with nxp official uboot/linux releases from source.codeaurora.org/external/imx/ repository

(as mainline is not supported by nxp)

https://source.codeaurora.org/external/imx/uboot-imx/tree/?h=imx_v2020.04_5.4.70_2.3.0

https://source.codeaurora.org/external/imx/linux-imx/tree/?h=imx_5.4.70_2.3.0

Documentation

https://www.nxp.com/design/software/embedded-software/i-mx-software/embedded-linux-for-i-mx-applications-processors:IMXLINUX?tab=In-Depth_Tab

Best regards
igor

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

steffendoster — Fri, 16 Apr 2021 06:59:52 GMT

Hello Igor,

well, this solution was even worse than the Mainline-Kernel. The NXP-Kernel isn't even starting on my old LPDDR2 design, while the mainline kernel at least started on this board.

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

igorpadykov — Fri, 16 Apr 2021 09:51:38 GMT

what reference board was used for custom board design - NXP i.MX6DL Sabre SD board or

some other third party board. What pmic used for custom board.

Best regards
igor

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

steffendoster — Fri, 16 Apr 2021 10:02:40 GMT

Years ago (I think 2014) I derived it from SabreSD-Quad (although we had only i.MX6S and later i.MX6DL. I think SabreSD-DualLite was available sometime later).
Since then I used the resulting configs and code to get about 10 different i.MX6-boards to work (everthing with LPDDR2).

From time to time I compare my Devicetree and configs still with SabreSD (now with SabreSD-DualLite)

I never had the issue that the Linux-Kernel was loaded but could not start.

I'm still using the old-style u-boot with c/h-boardfiles.

We're using PF0100 as PMIC

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

igorpadykov — Fri, 16 Apr 2021 11:04:02 GMT

could you please provide full uboot log.

Best regards
igor

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

steffendoster — Fri, 16 Apr 2021 11:08:14 GMT

Do you want the standard U-Boot-Outputs?

Well:

U-Boot 2015.01 (Apr 14 2021 - 17:24:36) CPU: Freescale i.MX6DL rev1.3 at 396 MHz CPU: Temperature 30 C Reset cause: POR Board: SIE-IMX6 I2C: ready DRAM: 1 GiB PMIC: PFUZE100 ID=0x10 MMC: FSL_SDHC: 0, FSL_SDHC: 1 In: serial Out: serial Err: serial Net: Using phy at 3 PHY: Micrel ksz9031 FEC [PRIME] Hit any key to stop autoboot: 0 => run netboot Booting from net ... FEC Waiting for PHY auto negotiation to complete......... TIMEOUT ! BOOTP broadcast 1 BOOTP broadcast 2 BOOTP broadcast 3 BOOTP broadcast 4 BOOTP broadcast 5 BOOTP broadcast 6 BOOTP broadcast 7 BOOTP broadcast 8 BOOTP broadcast 9 BOOTP broadcast 10 BOOTP broadcast 11 BOOTP broadcast 12 BOOTP broadcast 13 BOOTP broadcast 14 BOOTP broadcast 15 BOOTP broadcast 16 BOOTP broadcast 17 Retry time exceeded; starting again BOOTP broadcast 1 BOOTP broadcast 2 DHCP client bound to address 172.16.2.75 (255 ms) Using FEC device TFTP from server 172.16.0.72; our IP address is 172.16.2.75 Filename 'Board/board.dtb'. Load address: 0x18000000 Loading: ### 1.9 MiB/s done Bytes transferred = 30559 (775f hex) BOOTP broadcast 1 DHCP client bound to address 172.16.2.75 (3 ms) Using FEC device TFTP from server 172.16.0.72; our IP address is 172.16.2.75 Filename 'Board/linuximage'. Load address: 0x12000000 Loading: ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ########################################################### 3.9 MiB/s done Bytes transferred = 7536448 (72ff40 hex) Kernel image @ 0x12000000 [ 0x000000 - 0x72ff40 ] ## Flattened Device Tree blob at 18000000 Booting using the fdt blob at 0x18000000 Loading Device Tree to 4f58c000, end 4f59675e ... OK Starting kernel ...

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

steffendoster — Fri, 16 Apr 2021 13:43:45 GMT

By the way:
I would use the newest Script-Aid, but the link you sent me leads to LPDDR2 for i.MX6ULL and I have now a DDR3 and a i.MX6DL.

If I follow the link "i.MX6DQSDL DDR3 Script Aid" there it leads me only to the attachment "MX6Q_SabreSD_DDR3_register_programming_aid_v2.3.xlsx" which is useful for a i.MX6Q but somewhat useless for i.MX6DL because Q and DL have different Register-Adresses for most of the used Registers. If I want to use this script-aid, I have to redo all the Registers for i.MX6DL.

Is there a newer Script-Aid for i.MX6DL with DDR3?

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

igorpadykov — Fri, 16 Apr 2021 13:47:52 GMT

U-Boot 2015.01 is not supported by nxp, may be suggested to try for example 2015.04 uboot from nxp

source.codeaurora.org/external/imx/linux-imx repository:

https://source.codeaurora.org/external/imx/uboot-imx/tree/?h=nxp%2Fimx_v2015.04_4.1.15_1.0.0_ga

Use i.MX Porting Guide and AN4553 Using Open Source Debugging Tools for Linux on i.MX Processors

for any issues.

Best regards
igor

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

igorpadykov — Fri, 16 Apr 2021 13:51:34 GMT

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/i-MX6DL-SABRE-SDP-B-DDR3-Register-Programming-Aid/ta-p/1103549

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

steffendoster — Tue, 20 Apr 2021 07:06:16 GMT

OK, I will change this also.

Sadly I get the messages

common/cli_readline.c:265: undefined reference to `get_tbclk'
lib/time.c:54: undefined reference to `get_tbclk'
lib/time.c:80: undefined reference to `get_tbclk'

while compiling. Any Ideas?

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

steffendoster — Tue, 20 Apr 2021 09:21:59 GMT

OK, solved the compiling-problem:

had to add
#define CONFIG_GPT_TIMER
to the board-header-file

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

steffendoster — Tue, 20 Apr 2021 09:29:14 GMT

Hi Igor,

have the NXP-U-Boot running. Here is the log:

U-Boot 2015.04-00381-gede7538aef-dirty (Apr 20 2021 - 11:20:19) CPU: Freescale i.MX6DL rev1.3 at 396 MHz Reset cause: POR Board: SIE-IMX6 I2C: ready DRAM: 1 GiB PMIC: PFUZE100 ID=0x10 MMC: FSL_SDHC: 0, FSL_SDHC: 1 In: serial Out: serial Err: serial Setting Bootloader-Version: 1.0 Writing to MMC(1)... done Net: Using phy at 3 PHY: Micrel ksz9031 FEC [PRIME] Normal Boot Hit any key to stop autoboot: 0 => run usbboot Boot from USB resetting USB... USB0: USB EHCI 1.00 scanning bus 0 for devices... 7 USB Device(s) found USB1: USB EHCI 1.00 scanning bus 1 for devices... EHCI timed out on TD - token=0x80008c80 1 USB Device(s) found scanning usb for storage devices... 1 Storage Device(s) found scanning usb for ethernet devices... 0 Ethernet Device(s) found 30375 bytes read in 164 ms (180.7 KiB/s) 7212424 bytes read in 984 ms (7 MiB/s) Kernel image @ 0x12000000 [ 0x000000 - 0x6e0d88 ] ## Flattened Device Tree blob at 18000000 Booting using the fdt blob at 0x18000000 Loading Device Tree to 4f58b000, end 4f5956a6 ... OK Starting kernel ...

Same as mainline, after this the board doesn't do anyting more.

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

steffendoster — Wed, 21 Apr 2021 08:31:07 GMT

I don't exactly know, where the error occures, but im relatively sure it should be in the Kernel/Devicetree (mostly devicetree).

For comparison I use the decompiled devicetrees of my board and the sabresd. See Attached files.

The *-nxp devicetree is provided by NXP-Kernel, the other by mainline. sie-imx6 is my own devicetree.

PS: I think this shouldn't occure in a Forum where Devicetree could be exchanged:

Correct the highlighted errors and try again. The attachment's imx6dl-sabresd-nxp.dts content type (application/octet-stream) does not match its file extension and has been removed. The attachment's sie-imx6dl.dts content type (application/octet-stream) does not match its file extension and has been removed. The attachment's imx6dl-sabresd.dts content type (application/octet-stream) does not match its file extension and has been removed.

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

steffendoster — Wed, 21 Apr 2021 14:37:01 GMT

OK, we think its a miss match between U-Boot's DDR3 configuration (mainly the clocks) and the clocks the devicetree expects.

We have plotted out the different clocks of our DDR3-Config (top) and LPDDR2-Config (bottom). See attached Picture.

Re: Linux Kernel does not start after migrating from LPDDR2 to DDR3

igorpadykov — Thu, 22 Apr 2021 01:12:56 GMT

in general uboot and linux versions should be aligned, for example uboot v.2015.04 & L4.1.15, please try them:

https://source.codeaurora.org/external/imx/uboot-imx/tree/?h=nxp%2Fimx_v2015.04_4.1.15_1.0.0_ga

https://source.codeaurora.org/external/imx/linux-imx/tree/?h=imx_4.1.15_2.0.0_ga

Best regards
igor