topic iMX6qsabresd - fdt interaction between kernel and u-boot in i.MX Processors

iMX6qsabresd - fdt interaction between kernel and u-boot

matthiasniederm — Tue, 16 Apr 2013 10:02:46 GMT

Hello,

I have a Problem with u-boot and my Kernel. And i didn't found a howto about FDT, which explains it understandable.

Here is the output during the bootprocess:

U-Boot 2013.04-rc2 (Apr 16 2013 - 09:20:24) CPU: Freescale i.MX6Q rev1.2 at 792 MHz Reset cause: POR Board: MX6Q-SabreSD DRAM: 1 GiB MMC: FSL_SDHC: 0, FSL_SDHC: 1, FSL_SDHC: 2 *** Warning - bad CRC, using default environment In: serial Out: serial Err: serial Net: FEC [PRIME] Warning: FEC using MAC address from net device Hit any key to stop autoboot: 0 mmc1 is current device mmc - MMC sub system Usage: mmc read addr blk# cnt mmc write addr blk# cnt mmc erase blk# cnt mmc rescan mmc part - lists available partition on current mmc device mmc dev [dev] [part] - show or set current mmc device [partition] mmc list - lists available devices Booting from net ... FEC Waiting for PHY auto negotiation to complete. done BOOTP broadcast 1 BOOTP broadcast 2 DHCP client bound to address 192.168.1.103 Using FEC device TFTP from server 192.168.1.100; our IP address is 192.168.1.103 Filename 'uImage'. Load address: 0x12000000 Loading: ################################################################# ################################################################# ################################################################# ############################################################## 3.7 MiB/s done Bytes transferred = 3761024 (396380 hex) BOOTP broadcast 1 DHCP client bound to address 192.168.1.103 Using FEC device TFTP from server 192.168.1.100; our IP address is 192.168.1.103 Filename 'uImage'. Load address: 0x11000000 Loading: ################################################################# ################################################################# ################################################################# ############################################################## 3.7 MiB/s done Bytes transferred = 3761024 (396380 hex) ## Booting kernel from Legacy Image at 12000000 ... Image Name: Linux-3.0.35-2026-geaaf30e Image Type: ARM Linux Kernel Image (uncompressed) Data Size: 3760960 Bytes = 3.6 MiB Load Address: 10008000 Entry Point: 10008000 Verifying Checksum ... OK ## Flattened Device Tree from Legacy Image at 11000000 Image Name: Linux-3.0.35-2026-geaaf30e Image Type: ARM Linux Kernel Image (uncompressed) Data Size: 3760960 Bytes = 3.6 MiB Load Address: 10008000 Entry Point: 10008000 Verifying Checksum ... OK ERROR: uImage is not a fdt - must RESET the board to recover. Could not find a valid device tree U-Boot >

The Kernel starts after I type in:
bootm

My Hardware: im6qsabresd

Can someone give me a hint how to configure it the right way?

Regards

MaTT

Re: iMX6qsabresd - fdt interaction between kernel and u-boot

fabio_estevam — Tue, 16 Apr 2013 12:16:45 GMT

If you look at the default scripts (env -f -a default) they will load it correctly.

In your logs, you load uImage at 0x12000000, which is correct.

Then you load uImage again at 0x11000000, which is incorrect.

At 0x11000000 you must load imx6q-sabresd.dtb file instead.

In order to generate it, go to your Linux source and do a:

make imx6q-sabresd.dtb

Regards,

Fabio Estevam

Re: iMX6qsabresd - fdt interaction between kernel and u-boot

matthiasniederm — Wed, 17 Apr 2013 06:07:56 GMT

Hello,

yes you are right! But there is no rule to do that even no similiar..

I am using:

linux-imx6-imx_3.0.35_1.1.1
gcc-linaro-arm-linux-gnueabi-2012.04-20120426_linux

$ export ARCH=arm $ export CROSS_COMPILE=/gcc-linaro-arm-linux-gnueabi-2012.04-20120426_linux/bin/arm-linux-gnueabi- $ make imx6_defconfig # # configuration written to .config # $ make imx6q-sabresd.dtb scripts/kconfig/conf --silentoldconfig Kconfig make: *** No rule to make target `imx6q-sabresd.dtb'. Stop.

Regards

MaTT

Re: iMX6qsabresd - fdt interaction between kernel and u-boot

fabio_estevam — Wed, 17 Apr 2013 14:02:43 GMT

imx6q-sabresd.dtb needs to be used only when you run a mainline kernel.

If you are using 3.0.35 you do not need it.

In this case, in the U-boot prompt you need to do:

set boot_fdt no

And then U-boot will only load uImage into RAM and boot it via bootm.