[PATCH 0/2] console: pbl: correctly handle relocate_to_adr after pbl_set_putc

Ahmad Fatoum a.fatoum at pengutronix.de
Thu Sep 7 01:21:24 PDT 2023

pbl_set_putc may be called by a PBL entry point to store the absolute
address of a routine to be used for printing out a character.

If barebox happens to be located outside of the initially known RAM,
it will be relocated into it by means of relocate_to_adr(), but nothing
will take care to update the function pointer stored by pbl_set_putc.

This will usually continue to work until barebox sets up the MMU and
everything not known to be RAM is marked as eXecute Never. After that,
the next PBL console print will trigger an instruction abort.

Fix this by not storing the putc function pointer, but instead an offset
relative to _text.

This fixes the issue of barebox hanging on i.MX8M when located at an address
greater than 4G.

I thought about going further and make pbl_set_putc callable, even
before relocation. The problem here is that runtime_address() may
not be called on global variables defined in the same file for good
reasons described in its documentation. So that's left as future

Ahmad Fatoum (2):
  ARM: mmu64: mark barebox text section executable during early init
  console: pbl: correctly handle relocate_to_adr after pbl_set_putc

 arch/arm/cpu/mmu_64.c |  1 +
 pbl/console.c         | 13 ++++++++++---
 2 files changed, 11 insertions(+), 3 deletions(-)


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