incubator-nuttx/tools/mpfs
Eero Nurkkala b4d2944df7 tools/mpfs: prepare OpenSBI image
Polarfire Icicle board has only (128K - 256) bytes for the bootloader
in the non-volatile eNVM. This space is barely enough for running NuttX.
If OpenSBI is selected, it will be placed in DDR. This all means the
nuttx.bin file grows into gigabyte size, filling the unused space (ddr -
envm) with zeroes.

The memory layout is as follows:

MEMORY
{
    ddr  (rx)          : ORIGIN = 0x80000000, LENGTH = 4M
    envm (rx)          : ORIGIN = 0x20220100, LENGTH = 128K - 256
    l2lim  (rwx)       : ORIGIN = 0x08000000, LENGTH = 1024k
    l2zerodevice (rwx) : ORIGIN = 0x0A000000, LENGTH = 512k
}

OpenSBI library is used as a separate binary, which is stored into
eMMC or SD-card. It is then loaded into its precise location in DDR.

Thus, we separate OpenSBI from NuttX and end up with two images
by utilizing the objcopy options:

  --only-section=sectionpattern (-j in short)
  --remove-section=sectionpattern (-R in short)

This is only valid when CONFIG_MPFS_OPENSBI is set.

Signed-off-by: Eero Nurkkala <eero.nurkkala@offcode.fi>
2022-01-04 19:45:14 +08:00
..
Config.mk tools/mpfs: prepare OpenSBI image 2022-01-04 19:45:14 +08:00