Add debug_module bus device.

This should replace the ROM hack I implemented earlier, but for now both
exist together.

Back to the point where gdb connects, core jumps to ROM->RAM->ROM.

3 files changed, 14 insertions, 15 deletions

diff --git a/debug_rom/Makefile b/debug_rom/Makefile
index d66b84f..9d286c9 100644
--- a/debug_rom/Makefile
+++ b/debug_rom/Makefile
@@ -5,7 +5,7 @@ CC = $(RISCV)/bin/riscv64-unknown-elf-gcc
 OBJCOPY = $(RISCV)/bin/riscv64-unknown-elf-objcopy
 
 %.o:	%.S
-	$(CC) -c $<
+	$(CC) -I.. -c $<
 
 debug_rom.h:	debug_rom.raw
 	xxd -i $^ | sed "s/^unsigned/static const unsigned/" > $@
diff --git a/debug_rom/debug_rom.S b/debug_rom/debug_rom.S
index 577edbb..7130364 100755
--- a/debug_rom/debug_rom.S
+++ b/debug_rom/debug_rom.S
@@ -1,6 +1,8 @@
 # This code should be functional. Doesn't have to be optimal.
 # I'm writing it to prove that it can be done.
 
+#include "riscv/encoding.h"
+
 # TODO: Update these constants once they're finalized in the doc.
 
 #define DCSR                    0x790
@@ -10,16 +12,13 @@
 
 #define DSCRATCH                0x792
 
-#define MCPUID                  0xf00
-#define MHARTID                 0xf10
-
 # TODO: Should be 0x400
 #define DEBUG_RAM               (-0x400)
 #define DEBUG_RAM_SIZE          64
 
-#define SETHALTNOT              0x100
-#define CLEARHALTNOT            0x104
-#define CLEARDEBINT             0x108
+# TODO: Should be 0x100, 0x108
+#define SETHALTNOT              (-0x100)
+#define CLEARDEBINT             (-0x108)
 
         .global entry
         .global resume
@@ -31,7 +30,7 @@ entry:  j       _entry
 resume:
         # Clear debug interrupt.
 clear_debint:
-        csrr    s1, MHARTID
+        csrr    s1, CSR_MHARTID
         sw      s1, CLEARDEBINT(zero)
 clear_debint_loop:
         csrr    s1, DCSR
@@ -39,7 +38,7 @@ clear_debint_loop:
         bnez    s1, clear_debint_loop
 
         # Restore s1.
-        csrr    s1, MCPUID
+        csrr    s1, CSR_MISA
         bltz    s1, restore_not_32
 restore_32:
         lw      s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 4)(zero)
@@ -78,7 +77,7 @@ _entry:
 
 jdebugram:
         # Save s1 so that the debug program can use two registers.
-        csrr    s0, MCPUID
+        csrr    s0, CSR_MISA
         bltz    s0, save_not_32
 save_32:
         sw      s1, (DEBUG_RAM + DEBUG_RAM_SIZE - 4)(zero)
@@ -94,7 +93,7 @@ save_128:
         jr      zero, DEBUG_RAM
 
 spontaneous_halt:
-        csrr    s0, MHARTID
+        csrr    s0, CSR_MHARTID
         sw      s0, SETHALTNOT(zero)
         csrsi   DCSR, DCSR_HALT_OFFSET
 
diff --git a/debug_rom/debug_rom.h b/debug_rom/debug_rom.h
index 10c4fef..79162c2 100644
--- a/debug_rom/debug_rom.h
+++ b/debug_rom/debug_rom.h
@@ -1,17 +1,17 @@
 static const unsigned char debug_rom_raw[] = {
-  0x6f, 0x00, 0x40, 0x05, 0xf3, 0x24, 0x00, 0xf1, 0x23, 0x24, 0x90, 0x10,
+  0x6f, 0x00, 0x40, 0x05, 0xf3, 0x24, 0x50, 0xf1, 0x23, 0x2c, 0x90, 0xee,
   0xf3, 0x24, 0x00, 0x79, 0x93, 0xf4, 0x04, 0x40, 0xe3, 0x9c, 0x04, 0xfe,
-  0xf3, 0x24, 0x00, 0xf0, 0x63, 0xc6, 0x04, 0x00, 0x83, 0x24, 0xc0, 0xc3,
+  0xf3, 0x24, 0x00, 0xf1, 0x63, 0xc6, 0x04, 0x00, 0x83, 0x24, 0xc0, 0xc3,
   0x6f, 0x00, 0x80, 0x01, 0x93, 0x94, 0x14, 0x00, 0x63, 0xc6, 0x04, 0x00,
   0x83, 0x34, 0x80, 0xc3, 0x6f, 0x00, 0x80, 0x00, 0x13, 0x00, 0x00, 0x00,
   0x73, 0x24, 0x00, 0x79, 0x13, 0x74, 0x84, 0x00, 0x63, 0x04, 0x04, 0x00,
   0x6f, 0x00, 0x40, 0x05, 0x73, 0x24, 0x20, 0x79, 0x73, 0x00, 0x00, 0x10,
   0x73, 0x10, 0x24, 0x79, 0x73, 0x24, 0x00, 0x79, 0x13, 0x74, 0x74, 0x00,
-  0x13, 0x04, 0xd4, 0xff, 0x63, 0x16, 0x04, 0x02, 0x73, 0x24, 0x00, 0xf0,
+  0x13, 0x04, 0xd4, 0xff, 0x63, 0x16, 0x04, 0x02, 0x73, 0x24, 0x00, 0xf1,
   0x63, 0x46, 0x04, 0x00, 0x23, 0x2e, 0x90, 0xc2, 0x67, 0x00, 0x00, 0xc0,
   0x13, 0x14, 0x14, 0x00, 0x63, 0x46, 0x04, 0x00, 0x23, 0x3c, 0x90, 0xc2,
   0x67, 0x00, 0x00, 0xc0, 0x13, 0x00, 0x00, 0x00, 0x67, 0x00, 0x00, 0xc0,
-  0x73, 0x24, 0x00, 0xf1, 0x23, 0x20, 0x80, 0x10, 0x73, 0xe0, 0x01, 0x79,
+  0x73, 0x24, 0x50, 0xf1, 0x23, 0x20, 0x80, 0xf0, 0x73, 0xe0, 0x01, 0x79,
   0x73, 0x24, 0x00, 0x79, 0x13, 0x74, 0x04, 0x40, 0xe3, 0x0c, 0x04, 0xfe,
   0x6f, 0xf0, 0x1f, 0xfc
 };