20060303

1 files changed, 96 insertions, 0 deletions

diff --git a/os/boot/mpc/plan9boot.c b/os/boot/mpc/plan9boot.c
new file mode 100644
index 00000000..047474e3
--- /dev/null
+++ b/os/boot/mpc/plan9boot.c
@@ -0,0 +1,96 @@
+#include	"u.h"
+#include	"lib.h"
+#include	"mem.h"
+#include	"dat.h"
+#include	"fns.h"
+
+char *premature = "premature EOF\n";
+
+/*
+ *  read in a segment
+ */
+static long
+readseg(int dev, long (*read)(int, void*, long), long len, long addr)
+{
+	char *a;
+	long n, sofar;
+
+	a = (char *)addr;
+	for(sofar = 0; sofar < len; sofar += n){
+		n = 8*1024;
+		if(len - sofar < n)
+			n = len - sofar;
+		n = (*read)(dev, a + sofar, n);
+		if(n <= 0)
+			break;
+		print(".");
+	}
+	return sofar;
+}
+
+/*
+ *  boot
+ */
+int
+plan9boot(int dev, long (*seek)(int, long), long (*read)(int, void*, long))
+{
+	long n;
+	long addr;
+	void (*b)(void);
+	Exec *ep;
+
+	if((*seek)(dev, 0) < 0)
+		return -1;
+
+	/*
+	 *  read header
+	 */
+	ep = (Exec *) ialloc(sizeof(Exec), 0);
+	n = sizeof(Exec);
+	if(readseg(dev, read, n, (long) ep) != n){
+		print(premature);
+		return -1;
+	}
+	if(GLLONG(ep->magic) != Q_MAGIC){
+		print("bad magic 0x%lux not a plan 9 executable!\n", GLLONG(ep->magic));
+		return -1;
+	}
+
+	/*
+	 *  read text
+	 */
+	addr = PADDR(GLLONG(ep->entry));
+	n = GLLONG(ep->text);
+	print("%d", n);
+	if(readseg(dev, read, n, addr) != n){
+		print(premature);
+		return -1;
+	}
+
+	/*
+	 *  read data (starts at first page after kernel)
+	 */
+	addr = PGROUND(addr+n);
+	n = GLLONG(ep->data);
+	print("+%d@%8.8lux", n, addr);
+	if(readseg(dev, read, n, addr) != n){
+		print(premature);
+		return -1;
+	}
+
+	/*
+	 *  bss and entry point
+	 */
+	print("+%d\nstart at 0x%lux\n", GLLONG(ep->bss), GLLONG(ep->entry));
+	uartwait();
+	scc2stop();
+	splhi();
+
+	/*
+	 *  Go to new code. It's up to the program to get its PC relocated to
+	 *  the right place.
+	 */
+	b = (void (*)(void))(PADDR(GLLONG(ep->entry)));
+	(*b)();
+	return 0;
+}