The linker script CONSTRUCTORS keyword is only meaningful "when linking
object file formats which do not support arbitrary sections, such as
ECOFF and XCOFF"[1] and is ignored for other object file formats.
LLVM's lld does not yet accept (and ignore) CONSTRUCTORS, so just remove
CONSTRUCTORS from the linker script as it has no effect.
[1] https://sourceware.org/binutils/docs/ld/Output-Section-Keywords.html
(32 and 64-bit, LE and BE).
The changes were tested with QEMU's 'mips' target.
Most of the implementation was lifted from the ARM version, the appropriate
MIPS-specific things were implemented.
With these changes I am able to go all the way through the u-boot->ubldr->kernel
boot chain in QEMU on all combinations of bit-ness and endian-ness.
For the tests I've used FAT32 disk images (as FAT32 is supported by U-boot),
which include /boot/kernel/kernel and /boot/kernel/ubldr.bin
In U-boot I do:
fatload ide 0 <LOAD_ADDR> /boot/kernel/ubldr.bin; go <LOAD_ADDR>
where LOAD_ADDR is 80800000 for 32-bit and ffffffff80800000 for 64-bit
Then it's the usual ubldr that takes over and loads and starts a kernel.
Approved by: adrian (mentor)
Sponsored by: Smartcom - Bulgaria AD
Differential Revision: https://reviews.freebsd.org/D5313
