The sons basis (assuming he wasnt on the title at the time of death) will be the stepped up basis (FMV) at the date of death.

The you'll use SCh D, 1099B worksheet, scroll passed the brokerage info at the top.

Sale of Inherited property, date acquired will be Inherited, purchase price FMV at DOD, sales price, youve got the 1099S. You can double click, on the entry line and make adjustments to basis for the closing costs.