Closed
Description
In the following snippet
int main() {
// ...
uc_open(UC_ARCH_ARM64, UC_MODE_ARM, &uc);
u64 fpv = 3ULL << 20;
u64 psr = 0;
uc_reg_write(uc, UC_ARM64_REG_CPACR_EL1, &fpv);
uc_reg_write(uc, UC_ARM64_REG_PSTATE, &psr);
uc_hook hook{};
uc_hook_add(uc, &hook, UC_HOOK_INTR, (void*)InterruptHook, nullptr, 0, UINT64_MAX);
// ...
}
void InterruptHook(uc_engine* uc, u32 int_no, void* user_data) {
u64 esr{};
uc_reg_read(uc, UC_ARM64_REG_ESR_EL1, &esr);
// esr is always 0
}, when guest code takes a syscall from EL0, then attempting to fetch the esr_el1 register only ever returns 0. (The esr_elX registers are all zero and none provide any information.)