[OE-core] [PATCH 2/4] image.bbclass: add two hook funtions to support read-only rootfs

[ChenQi]

On 12/28/2012 02:22 AM, Saul Wold wrote:
> On 12/26/2012 06:57 PM, Qi.Chen at windriver.com wrote:
>> From: Chen Qi <Qi.Chen at windriver.com>
>>
>> read_only_rootfs_hook: this funtion is invoked only if 
>> 'read-only-rootfs'
>> is in IMAGE_FEATURES. It tweaks some basic files and makes populate-
>> volatile.sh script run at rootfs time.
>>
>> choose_volatile_conf_file: this function properly chooses the right
>> conf file for volatile storage handling according to the IMAGE_FEATURES.
>>
>> [YOCTO #3406]
>>
>> Signed-off-by: Chen Qi <Qi.Chen at windriver.com>
>> ---
>>   meta/classes/image.bbclass |   29 +++++++++++++++++++++++++++++
>>   1 file changed, 29 insertions(+)
>>
>> diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
>> index 8bf718a..15d42d0 100644
>> --- a/meta/classes/image.bbclass
>> +++ b/meta/classes/image.bbclass
>> @@ -394,6 +394,35 @@ zap_root_password () {
>>       mv ${IMAGE_ROOTFS}/etc/passwd.new ${IMAGE_ROOTFS}/etc/passwd
>>   }
>>
>> +# A hook function to support read-only-rootfs IMAGE_FEATURES
>> +read_only_rootfs_hook () {
>> +    # Tweak the mount option in fstab
>> +    sed '/rootfs/ s/defaults/ro/' < ${IMAGE_ROOTFS}/etc/fstab > 
>> ${IMAGE_ROOTFS}/etc/fstab.new
>> +    mv ${IMAGE_ROOTFS}/etc/fstab.new ${IMAGE_ROOTFS}/etc/fstab
>> +    # Change the value of ROOTFS_READ_ONLY in /etc/default/rcS to yes
>> +    sed 's/ROOTFS_READ_ONLY=no/ROOTFS_READ_ONLY=yes/' < 
>> ${IMAGE_ROOTFS}/etc/default/rcS > ${IMAGE_ROOTFS}/etc/default/rcS.new
>> +    mv ${IMAGE_ROOTFS}/etc/default/rcS.new 
>> ${IMAGE_ROOTFS}/etc/default/rcS
> For the above 2 sed/mv, can't you use sed -i instead, cuts down on the 
> exec overhead.
>
> Sau!
>
I've fixed this and sent out a V4.

Thanks,
Chen Qi
>> +    # Run populate-volatile.sh at rootfs time to set up basic files
>> +    # and directories to support read-only rootfs.
>> +    if [ ! -e ${IMAGE_ROOTFS}/etc/init.d/populate-volatile.sh ]; then
>> +        echo "${IMAGE_ROOTFS}/etc/init.d/populate-volatile.sh 
>> doesn't exist."
>> +        exit 1
>> +    else
>> +        ${IMAGE_ROOTFS}/etc/init.d/populate-volatile.sh
>> +    fi
>> +}
>> +
>> +# Choose the correct config file for volatile storage handling 
>> according to the image type
>> +choose_volatile_conf_file () {
>> +    if ${@base_contains("IMAGE_FEATURES", "x11-sato", "true", 
>> "false" ,d)}; then
>> +        cp 
>> ${IMAGE_ROOTFS}/etc/default/volatiles_stage/volatiles-readonly-sato \
>> + ${IMAGE_ROOTFS}/etc/default/volatiles/00_core_readonly
>> +    else
>> +        cp 
>> ${IMAGE_ROOTFS}/etc/default/volatiles_stage/volatiles-readonly-minimal \
>> + ${IMAGE_ROOTFS}/etc/default/volatiles/00_core_readonly
>> +    fi
>> +}
>> +
>>   # allow openssh accept login with empty password string
>>   openssh_allow_empty_password () {
>>       if [ -e ${IMAGE_ROOTFS}${sysconfdir}/ssh/sshd_config ]; then
>>
>
>