From 8026947ecdf9b023c3720b26bf257bf46f7a2805 Mon Sep 17 00:00:00 2001
From: Alejandro Soto <alejandro@34project.org>
Date: Sat, 10 Dec 2022 19:36:38 -0600
Subject: Implement rest of cp15 registers

---
 rtl/core/cp15/syscfg.sv | 66 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100644 rtl/core/cp15/syscfg.sv

(limited to 'rtl/core/cp15/syscfg.sv')

diff --git a/rtl/core/cp15/syscfg.sv b/rtl/core/cp15/syscfg.sv
new file mode 100644
index 0000000..599b682
--- /dev/null
+++ b/rtl/core/cp15/syscfg.sv
@@ -0,0 +1,66 @@
+`include "core/uarch.sv"
+`include "core/cp15/map.sv"
+
+module core_cp15_syscfg
+(
+	input  logic     clk,
+	                 rst_n,
+
+	input  logic     load,
+	                 transfer,
+	input  cp_opcode op2,
+	input  word      write,
+
+	output word      read
+);
+
+	logic mmu_enable, dcache_enable, icache_enable, high_vectors;
+
+	cp15_syscfg_ctrl ctrl, write_ctrl;
+
+	assign write_ctrl = write;
+
+	always_comb begin
+		ctrl = {$bits(ctrl){1'b0}};
+		ctrl.m = mmu_enable;
+		ctrl.c = dcache_enable;
+		ctrl.l = 1;
+		ctrl.d = 1;
+		ctrl.p = 1;
+		ctrl.z = 1;
+		ctrl.i = icache_enable;
+		ctrl.v = high_vectors;
+		ctrl.dt = 1;
+		ctrl.it = 1;
+
+		unique case(op2)
+			`CP15_SYSCFG_CTRL:
+				read = ctrl;
+
+			`CP15_SYSCFG_ACCESS:
+				read = 0;
+
+			default:
+				read = 0;
+		endcase
+	end
+
+	always @(posedge clk or negedge rst_n)
+		if(!rst_n) begin
+			mmu_enable <= 0;
+			high_vectors <= 0;
+			dcache_enable <= 0;
+			icache_enable <= 0;
+		end else if(transfer && !load)
+			unique case(op2)
+				`CP15_SYSCFG_CTRL: begin
+					mmu_enable <= write_ctrl.m;
+					high_vectors <= write_ctrl.v;
+					dcache_enable <= write_ctrl.c;
+					icache_enable <= write_ctrl.i;
+				end
+
+				default: ;
+			endcase
+
+endmodule
-- 
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