Upon the determination by the state board of regents to undertake and carry out any project or to refund outstanding bonds or notes, said board shall adopt a resolution describing generally the contemplated project and setting forth the estimated cost thereof, or describing the obligations to be refunded, fixing the amount of bonds or notes to be issued, the maturity or maturities, the interest rate or rates and all details in respect thereof. Such resolution shall contain such covenants as may be determined by the board as to the issuance of additional bonds or notes that may thereafter be issued payable from the net rents, profits and income of the residence halls or dormitories, the amendment or modification of the resolution authorizing the issuance of any bonds or notes, the manner, terms and conditions and the amount or percentage of assenting bonds or notes necessary to effectuate such amendment or modification, and such other covenants as may be deemed necessary or desirable. In the discretion of the board any bonds or notes issued under the terms of this subchapter may be secured by a trust indenture by and between the board and a corporate trustee, which may be any trust company or bank having the powers of a trust company within or without the boundaries of the state of Iowa, but no such trust indenture shall convey or mortgage the buildings or facilities or any part thereof. The provisions of this subchapter and of any resolution or other proceedings authorizing the issuance of bonds or notes and providing for the establishment and maintenance of adequate rates, fees or rentals and the application of the proceeds thereof shall constitute a contract with the holders of such bonds or notes.