1. 28 Jul, 2021 1 commit
    • Jeffrey Lee's avatar
      Allow RW/ZI sections to be used · 2b665896
      Jeffrey Lee authored
      * Instruct the linker to place any RW/ZI data sections in the last ~16MB
      of the memory map, starting from &ff000000 (with the current toolchain,
      giving it a fixed base address is much easier than giving it a variable
      base address)
      * The RW/ZI section is mapped as completely inaccessible to user mode
      * The initial content of the RW section is copied over shortly after MMU
      startup (in Continue_after_HALInit)
      * Since link's -bin option produces a file containing a copy of the
      (zero-initialised) ZI section, the kernel binary is now produced from a
      "binary with AIF header" AIF with the help of the new 'kstrip' tool.
      kstrip extracts just the RO and RW sections, ensuring the ROM doesn't
      contain a redundant block of zeros for the ZI section.
      
      This should make it easier to use C code & arbitrary libraries within
      the kernel, providing they're compiled with suitable settings (e.g.
      non-module, no FP, no stack checking, like HALs typically use)
      2b665896