i.MX 8X Bootloader

The u-boot bootloader is a GNU GPL licensed open source software. The u-boot input/output is redirected to one of the two onboard serial ports. In order to get access to the u-boot output, or the u-boot command-line interface in general, establish a serial connection between the host and target system.

The boot behavior is controlled via so called environment variables. They can be set with help of the u-boot command-line interface.

u-boot 2018.03
The source code for u-boot 2018.03 is provided on the congatec git server:

https://git.congatec.com/imx8_early_access/imx8_uboot_internal.git *see note
https://git.congatec.com/imx8x_early_access/imx8x_uboot_internal.git *see note

Fetch and build the bootloader standalone

conga-SMX8-X:

auth_os=auth_cntr ${cntr_addr}
baudrate=115200
board_name=SX8X
board_rev=iMX8QXP
boot_fdt=try
boot_os=booti ${loadaddr} - ${fdt_addr};
bootcmd=mmc dev ${mmcdev}; if mmc rescan; then if run loadbootscript; then run bootscript; else if test ${sec_boot} = yes; then if run loadcntr; then run mmcboot; else run netboot; fi; else if run loadimage; then run mmcboot; else run netboot; fi; fi; fi; else booti ${loadaddr} - ${fdt_addr}; fi
bootcmd_mfg=run mfgtool_args;if iminfo ${initrd_addr}; then if test ${tee} = yes; then bootm ${tee_addr} ${initrd_addr} ${fdt_addr}; else booti ${loadaddr} ${initrd_addr} ${fdt_addr}; fi; else echo "Run fastboot ..."; fastboot 0; fi;
bootdelay=3
bootscript=echo Running bootscript from mmc ...; source
cntr_addr=0x98000000
cntr_file=os_cntr_signed.bin
commit_atf=1cb68fa
commit_mkimage=dd023400
commit_scfw=f83a2bed
commit_secofw=92ef1143
console=ttyLP2
dom0fdt_file=imx8qxp-cgtsx8x-dom0.dtb
earlycon=lpuart32,0x5a080000
emmc_dev=0
ethact=FEC0
ethprime=eth0
fastboot_dev=mmc1
fdt_addr=0x83000000
fdt_file=imx8qxp-cgtsx8x-adv7533.dtb
fdt_high=0xffffffffffffffff
fdtcontroladdr=fd6732e8
image=Image
initrd_addr=0x83100000
initrd_high=0xffffffffffffffff
jh_mmcboot=setenv fdt_file imx8qxp-cgtsx8x-root.dtb;setenv boot_os 'scu_rm dtb ${fdt_addr}; booti ${loadaddr} - ${fdt_addr};'; run mmcboot;
jh_netboot=setenv fdt_file imx8qxp-cgtsx8x-root.dtb;setenv boot_os 'scu_rm dtb ${fdt_addr}; booti ${loadaddr} - ${fdt_addr};'; run netboot;
kboot=booti
loadaddr=0x80280000
loadbootscript=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${script};
loadcntr=fatload mmc ${mmcdev}:${mmcpart} ${cntr_addr} ${cntr_file}
loadfdt=fatload mmc ${mmcdev}:${mmcpart} ${fdt_addr} ${fdt_file}
loadimage=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${image}
loadm4image_0=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${m4_0_image}
m4_0_image=m4_0.bin
m4boot_0=run loadm4image_0; dcache flush; bootaux ${loadaddr} 0
mfgtool_args=setenv bootargs console=${console},${baudrate} rdinit=/linuxrc clk_ignore_unused
mmcargs=setenv bootargs console=${console},${baudrate} earlycon=${earlycon},${baudrate} root=${mmcroot}
mmcboot=echo Booting from mmc ...; run mmcargs; if test ${sec_boot} = yes; then if run auth_os; then run boot_os; else echo ERR: failed to authenticate; fi; else if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if run loadfdt; then run boot_os; else echo WARN: Cannot load the DT; fi; else echo wait for boot; fi;fi;
mmcdev=1
mmcpart=1
mmcroot=/dev/mmcblk1p2 rootwait rw
netargs=setenv bootargs console=${console},${baudrate} earlycon=${earlycon},${baudrate} root=/dev/nfs ip=dhcp nfsroot=${serverip}:${nfsroot},v3,tcp
netboot=echo Booting from net ...; run netargs;  if test ${ip_dyn} = yes; then setenv get_cmd dhcp; else setenv get_cmd tftp; fi; if test ${sec_boot} = yes; then ${get_cmd} ${cntr_addr} ${cntr_file}; if run auth_os; then run boot_os; else echo ERR: failed to authenticate; fi; else ${get_cmd} ${loadaddr} ${image}; if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if ${get_cmd} ${fdt_addr} ${fdt_file}; then run boot_os; else echo WARN: Cannot load the DT; fi; else booti; fi;fi;
panel=NULL
script=boot.scr
sd_dev=1
sec_boot=no
soc_type=imx8qxp
xenboot_common=${get_cmd} ${loadaddr} xen;${get_cmd} ${fdt_addr} ${dom0fdt_file};${get_cmd} ${xenlinux_addr} ${image};fdt addr ${fdt_addr};fdt resize 256;fdt set /chosen/module@0 reg <0x00000000 ${xenlinux_addr} 0x00000000 0x${filesize}>; fdt set /chosen/module@0 bootargs "${bootargs} ${xenlinux_bootargs}"; setenv bootargs ${xenhyper_bootargs};booti ${loadaddr} - ${fdt_addr};
xenhyper_bootargs=console=dtuart dtuart=/serial@5a080000 dom0_mem=2048M dom0_max_vcpus=2 dom0_vcpus_pin=true
xenlinux_addr=0x92000000
xenlinux_bootargs=
xenlinux_console=hvc0 earlycon=xen
xenmmcboot=setenv get_cmd "fatload mmc ${mmcdev}:${mmcpart}";setenv console ${xenlinux_console};run mmcargs;run xenboot_common;
xennetboot=setenv get_cmd dhcp;setenv console ${xenlinux_console};run netargs;run xenboot_common;

Edit variables fdt_file as follows:

=> editenv fdt_file
edit: imx8qxp-cgtsx8x-adv7533.dtb
=> boot

note: Contact congatec technical support to get access to the congatec git server.