Hi Richard, On Thu, Apr 11, 2024 at 10:16 PM Richard Henderson <richard.hender...@linaro.org> wrote: > > On 4/11/24 18:15, M Bazz wrote: > > diff --git a/target/sparc/ldst_helper.c b/target/sparc/ldst_helper.c > > index e581bb42ac..4f87e44a93 100644 > > --- a/target/sparc/ldst_helper.c > > +++ b/target/sparc/ldst_helper.c > > @@ -684,6 +684,7 @@ uint64_t helper_ld_asi(CPUSPARCState *env, > > target_ulong addr, > > case ASI_M_DIAGS: /* Turbosparc DTLB Diagnostic */ > > case ASI_M_IODIAG: /* Turbosparc IOTLB Diagnostic */ > > break; > > + case ASI_USERTXT: /* User code access */ > > case ASI_KERNELTXT: /* Supervisor code access */ > > oi = make_memop_idx(memop, cpu_mmu_index(env_cpu(env), true)); > > No, this also does not work, because it uses the wrong permissions (kernel > instead of > user). I have just sent a patch to fix both problems.
This thought just came to me. `lda` is a privileged instruction. It has to run in supervisor mode. So, I'm struggling to understand how the kernel permission was wrong. Isn't that the right permission for this instruction? I just want to have the right understanding, so that I'm more prepared for the next time. Here is a related excerpt from the Sparcv8 manual: "For each instruction access and each normal data access, the IU appends to the 32-bit memory address an 8-bit address space identifier, or ASI. The ASI encodes whether the processor is in supervisor or user mode, and whether the access is an instruction or data access. There are also privileged load/store alternate instructions (see below) that can provide an arbitrary ASI with their data addresses." Thank you, -bazz > > > r~
