diff options
Diffstat (limited to 'meta/classes/bootimg.bbclass')
| -rw-r--r-- | meta/classes/bootimg.bbclass | 45 |
1 files changed, 36 insertions, 9 deletions
diff --git a/meta/classes/bootimg.bbclass b/meta/classes/bootimg.bbclass index bcae2aeab1..c2d43c86ee 100644 --- a/meta/classes/bootimg.bbclass +++ b/meta/classes/bootimg.bbclass @@ -62,19 +62,46 @@ build_boot_bin() { install -m 444 ${STAGING_LIBDIR}/syslinux/ldlinux.sys ${HDDDIR}/ldlinux.sys - # Determine the 1024 byte block count for the final image. - BLOCKS=`du --apparent-size -ks ${HDDDIR} | cut -f 1` - SIZE=`expr $BLOCKS + ${BOOTIMG_EXTRA_SPACE}` + # Calculate the size required for the final image including the + # data and filesystem overhead. + # Sectors: 512 bytes + # Blocks: 1024 bytes + + # Determine the sector count just for the data + SECTORS=$(expr $(du --apparent-size -ks ${HDDDIR} | cut -f 1) \* 2) + + # Account for the filesystem overhead. This includes directory + # entries in the clusters as well as the FAT itself. + # Assumptions: + # < 16 entries per directory + # 8.3 filenames only + + # 32 bytes per dir entry + DIR_BYTES=$(expr $(find ${HDDDIR} | tail -n +2 | wc -l) \* 32) + # 32 bytes for every end-of-directory dir entry + DIR_BYTES=$(expr $DIR_BYTES + $(expr $(find ${HDDDIR} -type d | tail -n +2 | wc -l) \* 32)) + # 4 bytes per FAT entry per sector of data + FAT_BYTES=$(expr $SECTORS \* 4) + # 4 bytes per FAT entry per end-of-cluster list + FAT_BYTES=$(expr $FAT_BYTES + $(expr $(find ${HDDDIR} -type d | tail -n +2 | wc -l) \* 4)) + + # Use a ceiling function to determine FS overhead in sectors + DIR_SECTORS=$(expr $(expr $DIR_BYTES + 511) / 512) + # There are two FATs on the image + FAT_SECTORS=$(expr $(expr $(expr $FAT_BYTES + 511) / 512) \* 2) + SECTORS=$(expr $SECTORS + $(expr $DIR_SECTORS + $FAT_SECTORS)) + + # Determine the final size in blocks accounting for some padding + BLOCKS=$(expr $(expr $SECTORS \* 2) + ${BOOTIMG_EXTRA_SPACE}) # Ensure total sectors is an integral number of sectors per - # track or mcopy will complain. Sectors are 512 bytes, and and - # we generate images with 32 sectors per track. This calculation - # is done in blocks, which are twice the size of sectors, thus - # the 16 instead of 32. - SIZE=$(expr $SIZE + $(expr 16 - $(expr $SIZE % 16))) + # track or mcopy will complain. Sectors are 512 bytes, and we + # generate images with 32 sectors per track. This calculation is + # done in blocks, thus the mod by 16 instead of 32. + BLOCKS=$(expr $BLOCKS + $(expr 16 - $(expr $BLOCKS % 16))) IMG=${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.hddimg - mkdosfs -n ${BOOTIMG_VOLUME_ID} -S 512 -C ${IMG} ${SIZE} + mkdosfs -F 32 -n ${BOOTIMG_VOLUME_ID} -S 512 -C ${IMG} ${BLOCKS} # Copy HDDDIR recursively into the image file directly mcopy -i ${IMG} -s ${HDDDIR}/* ::/ |