simple boot.scr which import commands from a txt file

bootscr.txt
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#mkubootimage -A arm -C none -O netbsd -T script -a 0 -n "NetBSD/evbarm boot" bootscr.txt boot.scr
setenv myimportbootenv 'env import -t ${loadaddr} ${filesize}'
setenv myloadbootenv 'fatload mmc ${mmcdev} ${loadaddr} myenv.txt'
setenv prep 'mmc dev ${mmcdev}; mmc rescan;'
setenv distro_bootcmd 'run prep; run myloadbootenv; run myimportbootenv; run ${board}_bootcmd'

myenv.txt (make sure there's a empty blank line at the end of the file)
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am335x_bootcmd=fatload mmc ${mmcdev} 82000000 netbsd-BEAGLEBONE.ub; bootm 82000000 root=ld0a;
jetson-tk1_bootcmd=fatload mmc 1:1 ${kernel_addr_r} netbsd-TEGRA.ub; fatload mmc 1:1 ${fdt_addr_r} tegra124-${board}.dtb; fdt addr ${fdt_addr_r}; bootm ${kernel_addr_r} - ${fdt_addr_r} root=ld1a;
omap3_bootcmd=fatload mmc ${mmcdev} 81000000 netbsd-BEAGLEBOARD.ub; bootm 81000000 root=ld0a;
p2371-2180_bootcmd=echo "Implement me"