On 2/24/22 03:48, Amir Gonnen wrote:
+void helper_eret(CPUNios2State *env, uint32_t new_pc)
+{
+ uint32_t crs = cpu_get_crs(env);
+ if (crs == 0) {
+ env->regs[CR_STATUS] = env->regs[CR_ESTATUS];
+ } else {
+ env->regs[CR_STATUS] = env->regs[R_SSTATUS];
+ }
+ cpu_change_reg_set(env, crs, cpu_get_crs(env));
Hmm. This could probably use a comment that the second computation of cpu_get_crs is
using the value just restored into CR_STATUS.
+void helper_wrprs(CPUNios2State *env, uint32_t reg_index, uint32_t value)
+{
+ uint32_t prs = cpu_get_prs(env);
+ env->shadow_regs[prs][reg_index] = value;
+}
+
+uint32_t helper_rdprs(CPUNios2State *env, uint32_t reg_index)
+{
+ uint32_t prs = cpu_get_prs(env);
+ return env->shadow_regs[prs][reg_index];
+}
These are fairly easy to compute inline, e.g. for rdprs:
TCGv_i32 t = tcg_temp_i32_new();
TCGv_ptr p = tcg_temp_ptr_new();
tcg_gen_extract_i32(t, cpu_R[CR_STATUS],
R_CR_STATUS_CRS_SHIFT,
R_CR_STATUS_CRS_LENGTH);
tcg_gen_muli_i32(t, t, sizeof(uint32_t) * NUM_GP_REGS);
tcg_gen_ext_i32_ptr(p, t);
tcg_gen_add_ptr(p, p, cpu_env);
tcg_gen_ld_i32(t, p, offsetof(CPUNios2State, shadow_regs)
+ sizeof(uint32_t) * instr.a);
tcg_gen_addi_i32(cpu_R[instr.b], t, instr.imm16.s);
tcg_temp_free_ptr(p);
tcg_temp_free_i32(o);
+static void rdprs(DisasContext *dc, uint32_t code, uint32_t flags)
+{
+ I_TYPE(instr, code);
+ TCGv t = tcg_temp_new();
+ gen_helper_rdprs(t, cpu_env, tcg_const_i32(instr.a));
You're missing a gen_check_supervisor here and in wrprs.
static void eret(DisasContext *dc, uint32_t code, uint32_t flags)
{
- tcg_gen_mov_tl(cpu_R[CR_STATUS], cpu_R[CR_ESTATUS]);
- tcg_gen_mov_tl(cpu_R[R_PC], cpu_R[R_EA]);
+ gen_helper_eret(cpu_env, cpu_R[R_EA]);
As an existing bug to be fixed by a separate patch, eret should also check for
supervisor.
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r~
