Note 14 - Fair Value of Financial Instruments - Estimate Fair Value of Financial Instruments (Details)	Sep. 26, 2021 $ / shares yr	Sep. 27, 2020 $ / shares yr	Sep. 29, 2019 $ / shares yr
Measurement Input, Price Volatility [Member]
Warrant and rights, measurement input	0.43	0.84	0.48
Measurement Input, Risk Free Interest Rate [Member]
Warrant and rights, measurement input	0.0005	0.0012	0.0158
Measurement Input, Expected Term [Member]
Warrant and rights, measurement input | yr	0.5	1.5	2.5
Measurement Input, Share Price [Member]
Warrant and rights, measurement input | $ / shares	0.12	0.06	0.2