Implement mode privilege checks in MMU

4 files changed, 8 insertions, 5 deletions

diff --git a/rtl/core/arm810.sv b/rtl/core/arm810.sv
index 569b973..c0e717f 100644
--- a/rtl/core/arm810.sv
+++ b/rtl/core/arm810.sv
@@ -89,7 +89,7 @@ module arm810
 	);
 
 	word cpsr_rd, spsr_rd, psr_wr;
-	logic psr_write, psr_saved, update_flags, psr_wr_flags, psr_wr_control;
+	logic psr_write, psr_saved, update_flags, psr_wr_flags, psr_wr_control, privileged;
 	psr_mode mode;
 	psr_flags flags;
 	psr_intmask intmask;
diff --git a/rtl/core/mmu/mmu.sv b/rtl/core/mmu/mmu.sv
index d22f1cd..f8e808b 100644
--- a/rtl/core/mmu/mmu.sv
+++ b/rtl/core/mmu/mmu.sv
@@ -6,7 +6,8 @@ module core_mmu
 	input  logic          clk,
 	                      rst_n,
 
-	input  logic          mmu_enable /*verilator public*/,
+	input  logic          privileged,
+	                      mmu_enable /*verilator public*/,
 	input  mmu_base       mmu_ttbr /*verilator public*/,
 	input  word           mmu_dac,
 
diff --git a/rtl/core/mmu/pagewalk.sv b/rtl/core/mmu/pagewalk.sv
index ce25b19..eb36580 100644
--- a/rtl/core/mmu/pagewalk.sv
+++ b/rtl/core/mmu/pagewalk.sv
@@ -6,7 +6,8 @@ module core_mmu_pagewalk
 	input  logic          clk,
 	                      rst_n,
 
-	input  logic          mmu_enable,
+	input  logic          privileged,
+	                      mmu_enable,
 	input  mmu_base       mmu_ttbr,
 	input  word           mmu_dac,
 
@@ -56,7 +57,6 @@ module core_mmu_pagewalk
 		.write(hold_write),
 		.fault(access_fault),
 		.domain(entry_domain),
-		.privileged(1), //TODO
 		.fault_type(access_fault_type),
 		.*
 	);
diff --git a/rtl/core/psr.sv b/rtl/core/psr.sv
index c1fe0fd..41982c0 100644
--- a/rtl/core/psr.sv
+++ b/rtl/core/psr.sv
@@ -17,7 +17,8 @@ module core_psr
 	output psr_intmask mask,
 	output psr_mode    mode,
 	output word        cpsr_rd,
-	                   spsr_rd
+	                   spsr_rd,
+	output logic       privileged
 );
 
 	typedef struct packed
@@ -54,6 +55,7 @@ module core_psr
 	assign wr_word = psr_wr;
 	assign cpsr_rd = cpsr_word;
 	assign spsr_rd = spsr_word;
+	assign privileged = |mode[3:0]; // Not user
 	assign {wr_state.flags, wr_state.mask, wr_state.mode} = {wr_word.nzcv, wr_word.if_, wr_word.m};
 
 `ifdef VERILATOR