openwrt/target/linux/ath79/generic/base-files/lib/upgrade/openmesh.sh
Sven Eckelmann d0a9cf662e ath79: increase openmesh sysupgrade copy block size
The upgrade script for the openmesh sysupgrade procedure used always an 1
byte block size. This made it easier to seek the correct position in the CE
image and to make sure the right amount of data was copied. But this also
meant that the reading/writing of data required an excessive amount of
syscalls and copy operations.

A 5.4MB big sysupgrade image on an OM2P-HS v3 needed roughly 120s for the
write operation (170s in total) during the sysupgrade.

But it is possible to reduce this overhead slightly:

* index access to read the file size can be done in single 8 byte chunk
  (while doing the seek with byte granularity) because each size entry is
  example 8 bytes long
* the fwupgrade.cfg can be read as one block (while seeking to its position
  using its actual byte offset) because it should be rather small and fit
  into the RAM easily
* the kernel can be read in 1KB blocks (while seking to its positions using
  its actual byte offset) because the the size of the kernel is always a
  multiple of the NOR flash block size (64KB and 256KB)

This results in a sysupgrade write time of roughly 90s (140s in total).

This could be reduced even further when also using larger chunks for the
rootfs. But the squashfs rootfs image is at the moment always

  (256KB or 64KB) * block + 4 bytes

long. It would be expected that the time for the sysupgrade write could be
reduced to roughly 30s (80s in total) when busybox's dd would support
the iflag count_bytes.

Reported-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2020-12-28 19:37:24 +01:00

115 lines
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# The U-Boot loader of the OpenMesh devices requires image sizes and
# checksums to be provided in the U-Boot environment.
# The OpenMesh devices come with 2 main partitions - while one is active
# sysupgrade will flash the other. The boot order is changed to boot the
# newly flashed partition. If the new partition can't be booted due to
# upgrade failures the previously used partition is loaded.
cfg_value_get()
{
local cfg=$1 cfg_opt
local section=$2 our_section=0
local param=$3 our_param=
for cfg_opt in $cfg; do
[ "$cfg_opt" = "[$section]" ] && our_section=1 && continue
[ "$our_section" = "1" ] || continue
our_param=${cfg_opt%%=*}
[ "$param" = "$our_param" ] && echo ${cfg_opt##*=} && break
done
}
platform_do_upgrade_openmesh()
{
local img_path="$1"
local restore_backup
local setenv_script="/tmp/fw_env_upgrade"
local inactive_mtd="$(find_mtd_index $PART_NAME)"
local inactive_offset="$(cat /sys/class/mtd/mtd${inactive_mtd}/offset)"
local total_size="$(cat /sys/class/mtd/mtd${inactive_mtd}/size)"
local total_kbs=$((total_size / 1024))
local flash_start_mem=0x9f000000
local data_offset=$((64 * 1024))
# detect to which flash region the new image is written to.
#
# 1. check what is the mtd index for the first flash region on this
# device
# 2. check if the target partition ("inactive") has the mtd index of
# the first flash region
#
# - when it is: the new bootseq will be 1,2 and the first region is
# modified
# - when it isn't: bootseq will be 2,1 and the second region is
# modified
#
# The detection has to be done via the hardcoded mtd partition because
# the current boot might be done with the fallback region. Let us
# assume that the current bootseq is 1,2. The bootloader detected that
# the image in flash region 1 is corrupt and thus switches to flash
# region 2. The bootseq in the u-boot-env is now still the same and
# the sysupgrade code can now only rely on the actual mtd indexes and
# not the bootseq variable to detect the currently booted flash
# region/image.
#
# In the above example, an implementation which uses bootseq ("1,2") to
# detect the currently booted image would assume that region 1 is booted
# and then overwrite the variables for the wrong flash region (aka the
# one which isn't modified). This could result in a device which doesn't
# boot anymore to Linux until it was reflashed with ap51-flash.
local next_boot_part="1"
local primary_kernel_mtd="3"
[ "$inactive_mtd" = "$primary_kernel_mtd" ] || next_boot_part="2"
local cfg_size=$(dd if="$img_path" bs=8 skip=70 count=1 iflag=skip_bytes 2>/dev/null)
local cfg_length=$((0x$cfg_size))
local cfg_content=$(dd if="$img_path" bs=$cfg_length skip=$data_offset count=1 iflag=skip_bytes 2>/dev/null)
local kernel_size=$(dd if="$img_path" bs=8 skip=142 count=1 iflag=skip_bytes 2>/dev/null)
local kernel_length=$((0x$kernel_size))
local kernel_kbs=$((kernel_length / 1024))
local kernel_md5=$(cfg_value_get "$cfg_content" "vmlinux" "md5sum")
local rootfs_size=$(dd if="$img_path" bs=8 skip=214 count=1 iflag=skip_bytes 2>/dev/null)
local rootfs_length=$((0x$rootfs_size))
local rootfs_md5=$(cfg_value_get "$cfg_content" "rootfs" "md5sum")
local rootfs_checksize=$(cfg_value_get "$cfg_content" "rootfs" "checksize")
# take care of restoring a saved config
[ -n "$UPGRADE_BACKUP" ] && restore_backup="${MTD_CONFIG_ARGS} -j ${UPGRADE_BACKUP}"
# write image parts
mtd -q erase inactive
dd if="$img_path" bs=1 skip=$((data_offset + cfg_length + kernel_length)) count=$rootfs_length 2>&- | \
mtd -n -p $kernel_length $restore_backup write - $PART_NAME
dd if="$img_path" bs=1024 skip=$((data_offset + cfg_length)) count=$kernel_kbs iflag=skip_bytes 2>&- | \
mtd -n write - $PART_NAME
# prepare new u-boot env
if [ "$next_boot_part" = "1" ]; then
echo "bootseq 1,2" > $setenv_script
else
echo "bootseq 2,1" > $setenv_script
fi
printf "kernel_size_%i %i\n" $next_boot_part $kernel_kbs >> $setenv_script
printf "vmlinux_start_addr 0x%08x\n" $((flash_start_mem + inactive_offset)) >> $setenv_script
printf "vmlinux_size 0x%08x\n" ${kernel_length} >> $setenv_script
printf "vmlinux_checksum %s\n" ${kernel_md5} >> $setenv_script
printf "rootfs_size_%i %i\n" $next_boot_part $((total_kbs - kernel_kbs)) >> $setenv_script
printf "rootfs_start_addr 0x%08x\n" $((flash_start_mem+inactive_offset+kernel_length)) >> $setenv_script
printf "rootfs_size %s\n" $rootfs_checksize >> $setenv_script
printf "rootfs_checksum %s\n" ${rootfs_md5} >> $setenv_script
# store u-boot env changes
mkdir -p /var/lock
fw_setenv -s $setenv_script || {
echo "failed to update U-Boot environment"
return 1
}
}