Am335x Kernel Booting Issues

Hi,

I'm forwarding this to the SW team.

It looks like you do not have an EEPROM on your board. By default, u-boot reads the name of the board out of an EEPROM and selects the .dtb file name based on the board name. You should be able to just hardcode your board file name. Take a look at include/configs/am335x_evm.h. Look for the findfdt variable. You could probably just hard code fdtfile to your .dtb file name and remove all it if statements.

Steve K.

Hi,

As I see your kernel cannot find devicetree (dtb) file in /boot and therefore cannot load kernel correctly.

You are booting your board from sd card, right? Did you create your card, using the create-sdcard.sh script? What is the content of the /boot directory in the rootfs partition?

Can you stop your board at u-boot, run printenv & share the output?

Best Regards,
Yordan

Hey! I am aware of that. "Could not probe the EEPROM; Ignore warning since no chip. " is actually my custom message. I hardcoded the board name in the struct member.

The read_eeprom looks like this:

static int read_eeprom(struct am335x_baseboard_id *header)
{

strncpy("A335X_SK", header->name, sizeof(header->name));
puts("Could not probe the EEPROM; Ignore warning since no chip.\n");
return 0;
}

I think this is OK, otherwise U-Boot would not start.

I am booting from the SD card. It has 2 partitions. I created the card with the create-sdcard script. I then
overwritten the MLO and u-boot files in boot partition with my own files.

The content of the /boot is: MLO and, u-boot.img
rootfs contains the filessystem.

printenv says:

<START>

arch=arm
baudrate=115200
board=am335x
board_name=|�0@��0@
board_rev=\\Lˁ�
boot_fdt=try
boot_targets= mmc0 nand
bootcmd=for target in ${boot_targets}; do run bootcmd_${target}; done
bootcmd_mmc0=setenv devnum 0; setenv rootpart 2; run mmc_boot;
bootcmd_nand=run nandboot;
bootcmd_usb=setenv devnum 0; run usb_boot;
bootdelay=3
bootdir=/boot
bootenv=uEnv.txt
bootfile=zImage
bootpart=0:2
console=ttyO0,115200n8
cpu=armv7
dfu_alt_info_emmc=rawemmc mmc 0 3751936
dfu_alt_info_mmc=boot part 0 1;rootfs part 0 2;MLO fat 0 1;MLO.raw mmc 100 100;u-boot.img.raw mmc
300 400;spl-os-args.raw mmc 80 80;spl-os-image.raw mmc 900 2000;spl-os-args fat 0 1;spl-os-image f
at 0 1;u-boot.img fat 0 1;uEnv.txt fat 0 1
dfu_alt_info_nand=NAND.SPL part 0 1;NAND.SPL.backup1 part 0 2;NAND.SPL.backup2 part 0 3;NAND.SPL.b
ackup3 part 0 4;NAND.u-boot-spl-os part 0 5;NAND.u-boot part 0 6;NAND.u-boot-env part 0 7;NAND.u-b
oot-env.backup1 part 0 8;NAND.kernel part 0 9;NAND.rootfs part 0 10
dfu_alt_info_ram=kernel ram 0x80200000 0xD80000;fdt ram 0x80F80000 0x80000;ramdisk ram 0x81000000
0x4000000
eth1addr=d0:ff:50:22:eb:55
ethact=cpsw
ethaddr=d0:ff:50:22:eb:54
fdt_high=0xa0000000
fdtaddr=0x80F80000
fdtfile=undefined
findfdt=if test $board_name = A335BONE; then setenv fdtfile am335x-bone.dtb; fi; if test $board_na
me = A335BNLT; then setenv fdtfile am335x-boneblack.dtb; fi; if test $board_name = A33515BB; then
setenv fdtfile am335x-evm.dtb; fi; if test $board_name = A335X_SK; then setenv fdtfile am335x-evms
k.dtb; fi; if test $fdtfile = undefined; then echo WARNING: Could not determine device tree to use
; fi;
importbootenv=echo Importing environment from mmc ...; env import -t $loadaddr $filesize
loadaddr=0x80200000
loadbootenv=load mmc ${mmcdev} ${loadaddr} ${bootenv}
loadfdt=load mmc ${bootpart} ${fdtaddr} ${bootdir}/${fdtfile}
loadimage=load mmc ${bootpart} ${loadaddr} ${bootdir}/${bootfile}
loadramdisk=load mmc ${mmcdev} ${rdaddr} ramdisk.gz
mmc_boot=setenv devtype mmc; if mmc dev ${devnum}; then run mmcargs;run scan_boot; run mmcboot;set
env mmcdev 1; setenv bootpart 1:2; run mmcboot;fi
mmcargs=setenv bootargs console=${console} ${optargs} root=${mmcroot} rootfstype=${mmcrootfstype}
mmcboot=mmc dev ${mmcdev}; if mmc rescan; then echo SD/MMC found on device ${mmcdev};if run loadbo
otenv; then echo Loaded environment from ${bootenv};run importbootenv;fi;if test -n $uenvcmd; then
echo Running uenvcmd ...;run uenvcmd;fi;if run loadimage; then run mmcloados;fi;fi;
mmcdev=0
mmcloados=run mmcargs; if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if run loadfdt; t
hen bootz ${loadaddr} - ${fdtaddr}; else if test ${boot_fdt} = try; then bootz; else echo WARN: Ca
nnot load the DT; fi; fi; else bootz; fi;
mmcroot=/dev/mmcblk0p2 ro
mmcrootfstype=ext4 rootwait
mtdids=nand0=nand.0
mtdparts=mtdparts=nand.0:128k(NAND.SPL),128k(NAND.SPL.backup1),128k(NAND.SPL.backup2),128k(NAND.SP
L.backup3),256k(NAND.u-boot-spl-os),1m(NAND.u-boot),128k(NAND.u-boot-env),128k(NAND.u-boot-env.bac
kup1),8m(NAND.kernel),-(NAND.rootfs)
nandargs=setenv bootargs console=${console} ${optargs} root=${nandroot} rootfstype=${nandrootfstyp
e}
nandboot=echo Booting from nand ...; run nandargs; nand read ${fdtaddr} NAND.u-boot-spl-os; nand r
ead ${loadaddr} NAND.kernel; bootz ${loadaddr} - ${fdtaddr}
nandroot=ubi0:rootfs rw ubi.mtd=NAND.file-system,2048
nandrootfstype=ubifs rootwait=1
netargs=setenv bootargs console=${console} ${optargs} root=/dev/nfs nfsroot=${serverip}:${rootpath
},${nfsopts} rw ip=dhcp
netboot=echo Booting from network ...; setenv autoload no; dhcp; tftp ${loadaddr} ${bootfile}; tft
p ${fdtaddr} ${fdtfile}; run netargs; bootz ${loadaddr} - ${fdtaddr}
nfsopts=nolock
partitions=uuid_disk=${uuid_gpt_disk};name=rootfs,start=2MiB,size=-,uuid=${uuid_gpt_rootfs}
ramargs=setenv bootargs console=${console} ${optargs} root=${ramroot} rootfstype=${ramrootfstype}
ramboot=echo Booting from ramdisk ...; run ramargs; bootz ${loadaddr} ${rdaddr} ${fdtaddr}
ramroot=/dev/ram0 rw ramdisk_size=65536 initrd=${rdaddr},64M
ramrootfstype=ext2
rdaddr=0x81000000
rootpart=2
rootpath=/export/rootfs
scan_boot=echo Scanning ${devtype} ${devnum}...; for prefix in ${bootdir}; do for script in ${boot
file}; do run script_boot; done; done;
script_boot=if load ${devtype} ${devnum}:${rootpart} ${loadaddr} ${bootdir}/${bootfile}; then run
findfdt; load ${devtype} ${devnum}:${rootpart} ${fdtaddr} ${bootdir}/${fdtfile};fi;
soc=am33xx
spiargs=setenv bootargs console=${console} ${optargs} root=${spiroot} rootfstype=${spirootfstype}
spiboot=echo Booting from spi ...; run spiargs; sf probe ${spibusno}:0; sf read ${loadaddr} ${spis
rcaddr} ${spiimgsize}; bootz ${loadaddr}
spibusno=0
spiimgsize=0x362000
spiroot=/dev/mtdblock4 rw
spirootfstype=jffs2
spisrcaddr=0xe0000
static_ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}::off
stderr=serial
stdin=serial
stdout=serial
usb_boot=setenv devtype usb; run usb_init; if usb dev 0; then run usbargs;run scan_boot; bootz ${l
oadaddr} - ${fdtaddr}; fi
usb_init=usb start 0;
usbargs=setenv bootargs console=${console} ${optargs} root=${usbroot} rootfstype=${usbrootfstype}
usbnet_devaddr=d0:ff:50:22:eb:55
usbroot=/dev/sda2 rw
usbrootfstype=ext4 rootwait
vendor=ti
ver=U-Boot 2013.10-00189-g78d8ebd-dirty (Apr 09 2015 - 16:11:34)

Environment size: 5420/131067 bytes

<END>

So

board_name=|�0@��0@
board_rev=\\Lˁ�

does not look promissing. The values are not set. Can some one post the values of the AM335x EVM SK so i can set it with setenv?

Also:

console=ttyO0,115200n8

concerns me. I am connected via UART0 of AM3352. Maybe the output is sent somewhere else? 

I just set the file manually in u-boot and it worked, and I came here to post the happy news :)
Thank you anyway. I will also edit the header file.

Thank you all for help.