diff options
Diffstat (limited to 'lib/el3_runtime/aarch32/context_mgmt.c')
| -rw-r--r-- | lib/el3_runtime/aarch32/context_mgmt.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/lib/el3_runtime/aarch32/context_mgmt.c b/lib/el3_runtime/aarch32/context_mgmt.c index 02ae2a7e..29532e8c 100644 --- a/lib/el3_runtime/aarch32/context_mgmt.c +++ b/lib/el3_runtime/aarch32/context_mgmt.c @@ -200,7 +200,10 @@ void cm_prepare_el3_exit(uint32_t security_state) isb(); } else if (read_id_pfr1() & (ID_PFR1_VIRTEXT_MASK << ID_PFR1_VIRTEXT_SHIFT)) { - /* Set the NS bit to access HCR, HCPTR, CNTHCTL, VPIDR, VMPIDR */ + /* + * Set the NS bit to access NS copies of certain banked + * registers + */ write_scr(read_scr() | SCR_NS_BIT); isb(); @@ -231,6 +234,15 @@ void cm_prepare_el3_exit(uint32_t security_state) * translation are disabled. */ write64_vttbr(0); + + /* + * Avoid unexpected debug traps in case where HDCR + * is not completely reset by the hardware - set + * HDCR.HPMN to PMCR.N and zero the remaining bits. + * The HDCR.HPMN and PMCR.N fields are the same size + * (5 bits) and HPMN is at offset zero within HDCR. + */ + write_hdcr((read_pmcr() & PMCR_N_BITS) >> PMCR_N_SHIFT); isb(); write_scr(read_scr() & ~SCR_NS_BIT); |