This is a list of the Lenovo pages that can be checked to find possible BIOS
and EC updates.  It is not completely clear if Lenovo publishes all new
versions to the same page URL, so these may not link to the latest software,
but they will provide a reasonable starting point for any search for the
latest versions.

These pages provide the the description, checksum and binaries for the
bootable BIOS update CD images for both the current and historical releases.

b580    FIXME
b590    FIXME
e330    https://support.lenovo.com/hk/en/downloads/DS031908
e531    FIXME
l430    https://pcsupport.lenovo.com/us/en/downloads/DS029124
l440    https://pcsupport.lenovo.com/gb/en/downloads/DS037264
p15     https://pcsupport.lenovo.com/us/en/downloads/ds546302
p15g2   https://pcsupport.lenovo.com/us/en/downloads/ds551321
p51     https://pcsupport.lenovo.com/us/en/downloads/DS121296
t430    https://pcsupport.lenovo.com/gb/en/downloads/DS029252
t430s   https://pcsupport.lenovo.com/gb/en/downloads/DS029724
t430u   https://pcsupport.lenovo.com/gb/en/downloads/ds031725
t440p   https://pcsupport.lenovo.com/gb/en/downloads/DS037575
t470    https://pcsupport.lenovo.com/us/en/downloads/DS120429
t470p   https://pcsupport.lenovo.com/us/en/downloads/DS120707
t480    https://pcsupport.lenovo.com/us/en/downloads/DS502355
t530    https://pcsupport.lenovo.com/gb/en/downloads/DS029246
w530    https://pcsupport.lenovo.com/gb/en/downloads/DS029169
x131e   https://pcsupport.lenovo.com/us/en/downloads/DS029771
x220    https://support.lenovo.com/hk/en/downloads/DS018807
x230    https://pcsupport.lenovo.com/hk/en/downloads/DS029187
x230i   https://pcsupport.lenovo.com/us/en/downloads/ds029187
x230t   https://pcsupport.lenovo.com/gb/en/downloads/DS029683
x240    https://pcsupport.lenovo.com/us/en/downloads/DS035950
x250    https://pcsupport.lenovo.com/us/en/downloads/DS102288
x260    https://pcsupport.lenovo.com/us/en/downloads/DS105890
x270    https://pcsupport.lenovo.com/us/en/downloads/DS120442
x390    https://pcsupport.lenovo.com/us/en/downloads/ds539062
x60     https://support.lenovo.com/hk/en/downloads/migr-63145
x61     https://support.lenovo.com/hk/en/downloads/migr-67983