I am using uVision4.74 with STM32F407, I want to link my program to two sections, one section is 0x8000000 length 0x4000, and the other section is 0x8008000 length 0x38000. I did the setup in the options form Taget 'whatsoever', but the linked file used 0x8000000~0x80006AC and 0x8008000~0x08017C00
Is it a bug in the linker? It wasted so many space in section 1.
The GNU linker has historically been a pretty poor one for embedded work too. Then again you're not paying $10-20K per seat for it either.
Most are lazy, quick and predictable. I'd take this over smart, slow and unpredictable. See also Hammerstein-Equord
Good function placement is a science, it depends a lot on system level interactions, and chip choices (size, width, speed). A script that understands your system and priorities is the way to go.