[PATCH 03/23] sim/erc32: Perform pseudo-init of system if binary starts from non-zero address.

[Jiri Gaisler <jiri@gaisler.se>]

Binaries produced by most erc32 tool-chains do not include
system initialization. sis will detect this and initialize
necessary registers for memory and timer control.

	* erc32.c (mec_read) allow simulator memory size to be read
	by application. (boot_init) initialize memory and timers if
	start address is not 0.

	* erc32,c (exe_cmd) call boot_init if start address not 0
	* interf.c (run_sim) Likewise
---
 sim/erc32/erc32.c  | 24 ++++++++++++++++++++++++
 sim/erc32/func.c   |  1 +
 sim/erc32/interf.c |  1 +
 3 files changed, 26 insertions(+)

diff --git a/sim/erc32/erc32.c b/sim/erc32/erc32.c
index 4d4177e..4fa8f61 100644
--- a/sim/erc32/erc32.c
+++ b/sim/erc32/erc32.c
@@ -743,6 +743,14 @@ mec_read(addr, asi, data)
 	*data = read_uart(addr);
 	break;
 
+    case 0xF4:		/* simulator RAM size in bytes */
+	*data = 4096*1024;
+	break;
+
+    case 0xF8:		/* simulator ROM size in bytes */
+	*data = 1024*1024;
+	break;
+
     default:
 	set_sfsr(MEC_ACC, addr, asi, 1);
 	return (1);
@@ -1887,3 +1895,19 @@ sis_memory_read(addr, data, length)
     memcpy(data, mem, length);
     return (length);
 }
+
+extern struct pstate sregs;
+
+void
+boot_init ()
+{
+    mec_write(MEC_WCR, 0);	/* zero waitstates */
+    mec_write(MEC_TRAPD, 0);	/* turn off watch-dog */
+    mec_write(MEC_RTC_SCALER, sregs.freq-1); /* generate 1 MHz RTC tick */
+    mec_write(MEC_MEMCFG, (3 << 18) | (4 << 10)); /* 1 MB ROM, 4 MB RAM */
+    sregs.wim = 2;
+    sregs.psr = 0x110010e0;
+    sregs.r[30] = RAM_END;
+    sregs.r[14] = sregs.r[30] - 96*4;
+    mec_mcr |= 1;		/* power-down enabled */
+}
diff --git a/sim/erc32/func.c b/sim/erc32/func.c
index e6744ee..7034393 100644
--- a/sim/erc32/func.c
+++ b/sim/erc32/func.c
@@ -468,6 +468,7 @@ exec_cmd(sregs, cmd)
 	    }
 	    sregs->pc = len & ~3;
 	    sregs->npc = sregs->pc + 4;
+	    if ((sregs->pc != 0) && (ebase.simtime == 0)) boot_init();
 	    printf("resuming at 0x%08x\n",sregs->pc);
 	    if ((cmd2 = strtok(NULL, " \t\n\r")) != NULL) {
 		stat = run_sim(sregs, VAL(cmd2), 0);
diff --git a/sim/erc32/interf.c b/sim/erc32/interf.c
index 63b3f38..9ac455f 100644
--- a/sim/erc32/interf.c
+++ b/sim/erc32/interf.c
@@ -78,6 +78,7 @@ run_sim(sregs, icount, dis)
    init_stdio();
    sregs->starttime = time(NULL);
    irq = 0;
+   if ((sregs->pc != 0) && (ebase.simtime == 0)) boot_init();
    while (!sregs->err_mode & (icount > 0)) {
 
 	sregs->fhold = 0;
-- 
2.1.0