f0d50aa404
With the introduction of the stack canary breakpoint QEMU uncovered a different bug within coreboot. Currently the compiler optimizes over aggressively inline functions and memory stores. That also affects write_at_ble8(), which is supposed to store a single byte at time. The compiler however optimizes multiple byte stores into a single wider (and possibly unaligned) store operation. This can be seen in the emited assembly code of write_le16(), as used to install the EBDA: 401348a: 66 c7 04 25 13 04 00 movw $0x400,0x413 4013491: 00 00 04 Make sure that the compiler does not optimize multiple calls to write_at_ble8() by adding the volatile qualifier. The emitted assembly code of the same function changes to: 401394c: c6 04 25 13 04 00 00 movb $0x0,0x413 4013953: 00 4013954: c6 04 25 14 04 00 00 movb $0x4,0x414 401395b: 04 Fixes a strange bug in QEMU where it triggers the DEBUG breakpoint handler on unaligned 16-bit stores in the first 4KiB of memory. Aligned stores and store outside of the first 4KiB do not dispatch the DEBUG breakpoint handler. Change-Id: Ibbc661235a38c7f7540b656a67f067c3e51105d1 Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/85855 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Angel Pons <th3fanbus@gmail.com> |
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| .. | ||
| bsd | ||
| include/commonlib | ||
| storage | ||
| device_tree.c | ||
| fsp_relocate.c | ||
| iobuf.c | ||
| list.c | ||
| Makefile.mk | ||
| mem_pool.c | ||
| rational.c | ||
| region.c | ||
| sort.c | ||