tree 4d345372eefbed931efa2b7d58ea611f44a2cf5b
parent 407089cb0e41dedb82320bb706c1e328b0a0895b
author Joshua Seaton <joshuaseaton@fuchsia.infra.roller.google.com> 1734234642 -0800
committer Copybara-Service <copybara-worker@google.com> 1734234738 -0800

[roll] Roll fuchsia [kernel][x86] Make start16.S PIE-friendly

This change updates the start16.S to avoid some address constants which
will not be allowed when we start linking zircon as PIE. There were two
instances that were updated:
* One spot in the section intended only to be run in the kernel's
  linked-in copy at its high virtual address: given where it runs
  `movabs $x86_secondary_entry, %rbx` can be replaced by
  `lea x86_secondary_entry(%rip), %rbx`;
* Another spot intended to be run in a copied version of the code
  involves jumping to the linked-in, high entrypoint. Here pc-relative
  addressing is naturally not available to reference this, so we instead
  store the high virtual address of this entrypoint in the data
  structure provided to this code and load it out of there.

Original-Bug: 42164859
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1171484
Original-Revision: 2ec3af5fd1e5ac8a422ff6cf93ec6e441a6efeb8
GitOrigin-RevId: c1dafb0fcee653eff6a4e3bd8556c65fc63e4336
Change-Id: Ib2fc169c756a0f2cf1cb1cb301aee13c02859176