Developer Manual/Tools/Dual Flash

Dual Parallel Flash

You may do it yourself. That's a great tool getting away from bricks :)

Dual flash "pie". One for keeping working firmware image. Flash chips are selectable by a tumbler switch

Detailed "pie" structure. In a yellow ellipse you can see blue lines, that shows how to bend pins

VCC is connected to pull-up resistors

Resistors are about 100 k?. Please note that green and red wires are also connected to their corresponding flash chip's chip select signal