[PATCH 12/23] sim/erc32: Use separate memory_iread() function for instruction fetching.

Jiri Gaisler
2015-02-17T07:46:44Z

Use separate memory_iread() function for instruction fetching.
Speeds up execution and allows addition of an MMU at a later stage.

* erc32.c (memory_iread) New function to fetch instructions.
* interf.c (run_sim) Use memory_iread.
* sis.c (run_sim) As above.
---
sim/erc32/erc32.c | 24 ++++++++++++++++++++++++
sim/erc32/interf.c | 5 ++---
sim/erc32/sis.c | 8 ++------
sim/erc32/sis.h | 2 ++
4 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/sim/erc32/erc32.c b/sim/erc32/erc32.c
index c4474af..34a15de 100644
--- a/sim/erc32/erc32.c
+++ b/sim/erc32/erc32.c
@@ -1566,6 +1566,30 @@ store_bytes (mem, waddr, data, sz, ws)
/* Memory emulation */

int
+memory_iread(addr, data, ws)
+ uint32 addr;
+ uint32 *data;
+ int32 *ws;
+{
+ uint32 asi;
+ if ((addr >= mem_ramstart) && (addr < (mem_ramstart + mem_ramsz))) {
+ *data = *((uint32 *) & (ramb[addr & mem_rammask & ~3]));
+ *ws = mem_ramr_ws;
+ return (0);
+ } else if (addr < mem_romsz) {
+ *data = *((uint32 *) & (romb[addr & ~3]));
+ *ws = mem_romr_ws;
+ return (0);
+ }
+
+ printf("Memory exception at %x (illegal address)\n", addr);
+ if (sregs.psr & 0x080) asi = 9; else asi = 8;
+ set_sfsr(UIMP_ACC, addr, asi, 1);
+ *ws = MEM_EX_WS;
+ return (1);
+}
+
+int
memory_read(asi, addr, data, sz, ws)
int32 asi;
uint32 addr;
diff --git a/sim/erc32/interf.c b/sim/erc32/interf.c
index 3a72e7f..981aa11 100644
--- a/sim/erc32/interf.c
+++ b/sim/erc32/interf.c
@@ -94,9 +94,8 @@ run_sim(sregs, icount, dis)
if (sregs->pc == 0 || sregs->npc == 0)
printf ("bogus pc or npc\n");
#endif
- mexc = memory_read(sregs->asi, sregs->pc, &sregs->inst,
- 2, &sregs->hold);
-#if 1 /* DELETE ME! for debugging purposes only */
+ mexc = memory_iread(sregs->pc, &sregs->inst, &sregs->hold);
+#if 0 /* DELETE ME! for debugging purposes only */
if (sis_verbose > 2)
printf("pc %x, np %x, sp %x, fp %x, wm %x, cw %x, i %08x\n",
sregs->pc, sregs->npc,
diff --git a/sim/erc32/sis.c b/sim/erc32/sis.c
index c6e9714..8bc2283 100644
--- a/sim/erc32/sis.c
+++ b/sim/erc32/sis.c
@@ -83,7 +83,7 @@ run_sim(sregs, icount, dis)
uint64 icount;
int dis;
{
- int irq, mexc, deb, asi;
+ int irq, mexc, deb;

sregs->starttime = get_time();
init_stdio();
@@ -92,11 +92,7 @@ run_sim(sregs, icount, dis)
irq = 0;
while (icount > 0) {

- if (sregs->psr & 0x080)
- asi = 9;
- else
- asi = 8;
- mexc = memory_read(asi, sregs->pc, &sregs->inst, 2, &sregs->hold);
+ mexc = memory_iread(sregs->pc, &sregs->inst, &sregs->hold);
sregs->icnt = 1;
if (sregs->annul) {
sregs->annul = 0;
diff --git a/sim/erc32/sis.h b/sim/erc32/sis.h
index 330036b..604d344 100644
--- a/sim/erc32/sis.h
+++ b/sim/erc32/sis.h
@@ -170,6 +170,7 @@ extern void sim_halt (void);
extern void exit_sim (void);
extern void init_stdio (void);
extern void restore_stdio (void);
+extern int memory_iread (uint32 addr, uint32 *data, int32 *ws);
extern int memory_read (int32 asi, uint32 addr, uint32 *data,
int32 sz, int32 *ws);
extern int memory_write (int32 asi, uint32 addr, uint32 *data,
@@ -180,6 +181,7 @@ extern int sis_memory_read (uint32 addr, char *data,
uint32 length);

/* func.c */
+extern struct pstate sregs;
extern void set_regi (struct pstate *sregs, int32 reg,
uint32 rval);
extern void get_regi (struct pstate *sregs, int32 reg, char *buf);
--
2.1.0