1 files changed, 59 insertions, 0 deletions
diff --git a/rtl/core/mmu/fault.sv b/rtl/core/mmu/fault.sv
new file mode 100644
index 0000000..e922284
--- /dev/null
+++ b/rtl/core/mmu/fault.sv
@@ -0,0 +1,59 @@
+`include "core/mmu/format.sv"
+`include "core/uarch.sv"
+
+module core_mmu_fault
+(
+	input  logic          valid_entry,
+	                      skip_perms,
+	input  word           mmu_dac,
+	input  mmu_domain     domain,
+	input  logic[1:0]     ap,
+
+	output logic          fault, 
+	output mmu_fault_type fault_type
+);
+
+	mmu_domain_ctrl domain_ctrl;
+
+	always_comb begin
+		unique case(domain)
+			4'h0: domain_ctrl = mmu_dac[1:0];
+			4'h1: domain_ctrl = mmu_dac[3:2];
+			4'h2: domain_ctrl = mmu_dac[5:4];
+			4'h3: domain_ctrl = mmu_dac[7:6];
+			4'h4: domain_ctrl = mmu_dac[9:8];
+			4'h5: domain_ctrl = mmu_dac[11:10];
+			4'h6: domain_ctrl = mmu_dac[13:12];
+			4'h7: domain_ctrl = mmu_dac[15:14];
+			4'h8: domain_ctrl = mmu_dac[17:16];
+			4'h9: domain_ctrl = mmu_dac[19:18];
+			4'ha: domain_ctrl = mmu_dac[21:20];
+			4'hb: domain_ctrl = mmu_dac[23:22];
+			4'hc: domain_ctrl = mmu_dac[25:24];
+			4'hd: domain_ctrl = mmu_dac[27:26];
+			4'he: domain_ctrl = mmu_dac[29:28];
+			4'hf: domain_ctrl = mmu_dac[31:30];
+		endcase
+
+		fault = 0;
+		fault_type = `MMU_FAULT_ACCESS;
+
+		if(!valid_entry) begin
+			fault = 1;
+			fault_type = `MMU_FAULT_WALK;
+		end else if(!skip_perms) begin
+			if(!domain_ctrl.allowed) begin
+				fault = 1;
+				fault_type = `MMU_FAULT_DOMAIN;
+			end else if(!domain_ctrl.manager)
+				unique case(ap)
+					2'b00:
+						fault = 1;
+
+					//TODO: los demás solo se tienen efecto para unprivileged
+					default: ;
+				endcase
+		end
+	end
+
+endmodule