From c279b66691509cfc4445a568dab29a3282f03f3f Mon Sep 17 00:00:00 2001
From: Joshua Wise <joshua@nyus.joshuawise.com>
Date: Sat, 19 Apr 2008 06:12:53 -0400
Subject: [PATCH 1/1] alu_ext

---
 Makefile       |  2 +-
 System.v       |  1 +
 allinsns.v     |  1 +
 bootrom.asm    |  8 ++++----
 insn_alu_ext.v | 45 +++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 52 insertions(+), 5 deletions(-)
 create mode 100644 insn_alu_ext.v

diff --git a/Makefile b/Makefile
index 8b2feed..fae41fe 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@ VLOGS = 7seg.v GBZ80Core.v insn_call-callcc.v insn_incdec16.v \
 	insn_alu_a.v insn_halt.v insn_jp-jpcc.v insn_ld_hl_reg.v \
 	insn_ld_reg_imm8.v insn_ldx_ahl.v insn_push_reg.v insn_vop_intr.v \
 	Timer.v LCDC.v insn_ldm8_a.v insn_ldm16_a.v Framebuffer.v \
-	insn_ldbcde_a.v
+	insn_ldbcde_a.v insn_alu_ext.v insn_bit.v insn_two_byte.v
 
 all: CoreTop_rom.svf CoreTop_diag.svf CoreTop_bootrom.svf CoreTop.twr
 
diff --git a/System.v b/System.v
index 0e464f5..caa6ae3 100644
--- a/System.v
+++ b/System.v
@@ -36,6 +36,7 @@ module MiniRAM(			/* XXX will need to go INSIDE the CPU for when we do DMA */
 			odata <= ram[address[6:0]];
 		end
 	end
+endmodule
 
 module InternalRAM(
 	input [15:0] address,
diff --git a/allinsns.v b/allinsns.v
index 5ca51d6..6c1c487 100644
--- a/allinsns.v
+++ b/allinsns.v
@@ -28,3 +28,4 @@
 `include "insn_ldbcde_a.v"
 `include "insn_two_byte.v"
 `include "insn_bit.v"
+`include "insn_alu_ext.v"
diff --git a/bootrom.asm b/bootrom.asm
index 4f71d5e..b2a2db8 100644
--- a/bootrom.asm
+++ b/bootrom.asm
@@ -28,8 +28,8 @@ Addr_0007:
 	LD HL,$8010		; $0024
 Addr_0027:
 	LD A,[DE]		; $0027
-	CALL $0095		; $0028
-	CALL $0096		; $002b
+	CALL a95		; $0028
+	CALL a96		; $002b
 	INC DE		; $002e
 	LD A,E		; $002f
 	CP $34		; $0030
@@ -112,8 +112,8 @@ Addr_0086:
 
 	; ==== Graphic routine ====
 
-	LD C,A		; $0095  "Double up" all the bits of the graphics data
-	LD B,$04		; $0096     and store in Video RAM
+a95:	LD C,A		; $0095  "Double up" all the bits of the graphics data
+a96:	LD B,$04		; $0096     and store in Video RAM
 Addr_0098:
 	PUSH BC		; $0098
 	RL C			; $0099
diff --git a/insn_alu_ext.v b/insn_alu_ext.v
new file mode 100644
index 0000000..1b7825b
--- /dev/null
+++ b/insn_alu_ext.v
@@ -0,0 +1,45 @@
+`ifdef EXECUTE
+	`INSN_ALU_EXT: begin
+		if ((opcode[2:0] == `INSN_reg_dHL) && (cycle == 0))
+			`EXEC_READ(`_HL)
+		else begin
+			`EXEC_INC_PC
+			case (opcode[2:0])
+			`INSN_reg_A:    tmp <= `_A;
+			`INSN_reg_B:    tmp <= `_B;
+			`INSN_reg_C:    tmp <= `_C;
+			`INSN_reg_D:    tmp <= `_D;
+			`INSN_reg_E:    tmp <= `_E;
+			`INSN_reg_H:    tmp <= `_H;
+			`INSN_reg_L:    tmp <= `_L;
+			`INSN_reg_dHL:  tmp <= rdata;
+			endcase
+		end
+	end
+`endif
+
+`ifdef WRITEBACK
+	`INSN_ALU_EXT: begin
+		if (opcode[2:0] == `INSN_reg_dHL) begin
+			if(cycle == 0) begin end
+			else if(cycle == 1) begin
+				`EXEC_WRITE(`_HL, alu_res)
+			end else begin
+				`EXEC_NEWCYCLE
+			end
+		end else begin
+			case(opcode[2:0])
+			`INSN_reg_B: `_B <= alu_res;
+			`INSN_reg_C: `_C <= alu_res;
+			`INSN_reg_D: `_D <= alu_res;
+			`INSN_reg_E: `_E <= alu_res;
+			`INSN_reg_H: `_H <= alu_res;
+			`INSN_reg_L: `_L <= alu_res;
+			`INSN_reg_A: `_A <= alu_res;
+			`INSN_reg_dHL: begin end /* eat dicks */
+			endcase
+			`_F <= {f_res,`_F[3:0]};
+			`EXEC_NEWCYCLE
+		end
+	end
+`endif
-- 
2.43.0