Yes, the Government has introduced mandatory testing at the border for people who have resided in an area with a quarantine obligation (external website) (only available in Norwegian).
Persons who have resided in an area with a quarantine obligation during the last 14 days before arrival in Norway must test for Covid-19 at the border crossing point in Norway. The test must be antigen rapid test or PCR test.
Some exceptions to the requirement in the case have been mentioned on the Government's website.
This requirement applies in addition to the requirement for a negative test before entry to Norway for specific groups and the requirements for quarantine hotels and quarantine after entry.
Because of control considerations and test capacity, the government has closed some border crossing points. In the article on the government's page, you will find an overview of open border crossing points (external website).
The UDI does not know more than what is stated in the article on regjeringen.no. You will find updated information about the test requirement after entry on helsenorge.no (external website) when more details are ready.