I tried to enable prints in arch/arm/boot/compressed/head.s by enabling macro DEBUG.
Enabled CONFIG_EARLY_PRINTK and CONFIG_DEBUG_LL. But not able too see any UART prints. Could you please suggest how to enable early prints.
These are the Parameters passed from Uboot.
printenv
baudrate=115200
boot_fdt=try
bootcmd=echo bootcmd...; mmc dev ${mmcdev}; if mmc rescan; then mmc read 10800000 400 200; source 10800000;echo defaulting to ORINOCO kernel at ${kernelimageaddr}...; run loadkernelimage; bootm ${loadaddr}; fi;
bootdelay=0
bootscript=echo Running bootscript from mmc ...; source 10800000
console=ttymxc1
emergencysize=4000
fdt_addr=0x18000000
fdt_file=imx6dl-wandboard.dtb
image=zImage
initrd_high=0xffffffff
ip_dyn=yes
kernelimageaddr=800
kernelsize=2000
loadaddr=11000000
loadbootscript=mmc read 10800000 400 200;
loadfdt=fatload mmc ${mmcdev}:${mmcpart} ${fdt_addr} ${fdt_file}
loadimage=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${image}
loadkernelimage=mmc read ${loadaddr} ${kernelimageaddr} ${kernelsize}
loadsplashimage=mmc dev ${mmcdev}; mmc read ${splashcpaddr} ${splashimageaddr} ${splashimagesize}; cp.b ${splashcpaddr} ${splashloadaddr}
mmcargs=setenv bootargs console=${console},${baudrate} root=${mmcroot} init=/lib/systemd/systemd nosmp earlyprintk log_buf_len=16M debug mem=512M loglevel=8; run videoargs
mmcboot=echo Booting from mmc ...; run mmcargs; if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if run loadfdt; then bootz ${loadaddr} - ${fdt_addr}; else if test ${boot_fdt} = try; then bootz; else echo WARN: Cannot load the DT; fi; fi; else bootz; fi;
mmcdev=0
mmcpart=1
mmcroot=/dev/mmcblk0p7 rootwait rw
netargs=setenv bootargs console=${console},${baudrate} root=/dev/nfs ip=dhcp nfsroot=${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; ${get_cmd} ${image}; if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if ${get_cmd} ${fdt_addr} ${fdt_file}; then bootz ${loadaddr} - ${fdt_addr}; else if test ${boot_fdt} = try; then bootz; else echo WARN: Cannot load the DT; fi; fi; else bootz; fi;
script=boot.scr
splashcpaddr=100000
splashimageaddr=600splashimagesize=1efdt_high=0xffffffff
splashloadaddr=41F80000
splashpos=m,m
update_sd_firmware=if test ${ip_dyn} = yes; then setenv get_cmd dhcp; else setenv get_cmd tftp; fi; if mmc dev ${mmcdev}; then if ${get_cmd} ${update_sd_firmware_filename}; then setexpr fw_sz ${filesize} / 0x200; setexpr fw_sz ${fw_sz} + 1; mmc write ${loadaddr} 0x2 ${fw_sz}; fi; fi
update_sd_firmware_filename=u-boot.imx
videoargs=setenv nextcon 0; if hdmidet; then setenv bootargs ${bootargs} video=mxcfb${nextcon}:dev=hdmi,1280x720M@60,if=RGB24; setenv fbmen fbmem=28M; setexpr nextcon ${nextcon} + 1; else echo - no HDMI monitor;fi; i2c dev 1; if i2c probe 0x10; then setenv bootargs ${bootargs} video=mxcfb${nextcon}:dev=lcd,800x480@60,if=RGB666; if test 0 -eq ${nextcon}; then setenv fbmem fbmem=10M; else setenv fbmem ${fbmem},10M; fi; setexpr nextcon ${nextcon} + 1; else echo '- no FWBADAPT-7WVGA-LCD-F07A-0102 display';fi; setenv bootargs ${bootargs} ${fbmem}
Environment size: 2949/8188 bytes