Beijing, April 30 : Key enterprises like SAIC Motor, US electric carmaker Tesla and semiconductor makers like SMIC and Hua Hong Semiconductor have resumed 80-90 per cent of their production in Shanghai which is under Covid lockdowns, The Global Times reported on Saturday. Companies on Shanghai's initial whitelist have resumed over 80 per cent of their production while chip makers now maintain over 90 per cent production. China has established a "whitelist" approach to support the resumption of work for key companies and minimise the impact of Covid-19 on the supply chain. "By now, Shanghai's whitelist authorises a total of 1,854 companies to resume work," the report said, quoting officials. To help workers return to their workplaces, Shanghai has issues digital pass cards that carry personal information like identity, company and a negative Covid test result, "with shuttle buses transporting them to their companies under closed-loop management". The city has so far issued over 10,000 such cards and another 30,000 more workers have returned to their posts via other measures, the report mentioned. The ongoing Covid-19 lockdowns in China are set to make a huge dent in Apple revenue for the April-June quarter as the company has indicated up to $8 billion loss in sales. In Shanghai, 31 companies run production facilities that supply to Apple. According to reports, some Apple suppliers have reopened facilities in bubble-like environments where workers are staying inside the premises. Apple's biggest supplier Foxconn has kept production going at its biggest iPhone-assembly plant in the Chinese city of Zhengzhou. In Shanghai's outbreak, nearly all victims have been elderly, unvaccinated residents with underlying health problems, according to Chinese officials. /IANS