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raspi-alpine-builder/resources/boot.cmd
2019-11-03 16:04:17 +01:00

54 lines
1.3 KiB
Batchfile

# static config
setenv boot_partition_a 2
setenv boot_partition_b 3
setenv boot_limit 2
setenv boot_partition_base "/dev/mmcblk0p"
# set default values if env not set
if printenv boot_count; then
else
setenv boot_count 1
fi
if printenv boot_partition; then
# check if valid partition a or b
if test ${boot_partition} -ne ${boot_partition_a} && test ${boot_partition} -ne ${boot_partition_b}; then
setenv boot_partition ${boot_partition_a}
fi
else
setenv boot_partition ${boot_partition_a}
fi
# switch boot partition if boot count exceed limit
if test ${boot_count} -ge ${boot_limit}; then
echo "!!! Boot limit exceed !!!"
if test ${boot_partition} -eq ${boot_partition_a}; then
setenv boot_partition ${boot_partition_b}
else
setenv boot_partition ${boot_partition_a}
fi
setenv boot_count 0
echo "Switch active partition to ${boot_partition_base}${boot_partition}"
fi
# increase boot_count
setexpr boot_count ${boot_count} + 1
# store settings
saveenv
# load bootargs from pi boot loader
fdt addr ${fdt_addr} && fdt get value bootargs /chosen bootargs
# overwrite boot partition
setexpr bootargs sub " root=[^ ]+" " root=${boot_partition_base}${boot_partition}" "${bootargs}"
# load kernel and boot
ext4load mmc 0:${boot_partition} ${kernel_addr_r} /boot/uImage
bootm ${kernel_addr_r} - ${fdt_addr}
reset