added io/seg utility

1 files changed, 47 insertions, 0 deletions

diff --git a/sys/src/cmd/seg.c b/sys/src/cmd/seg.c
new file mode 100644
index 000000000..367aad988
--- /dev/null
+++ b/sys/src/cmd/seg.c
@@ -0,0 +1,47 @@
+#include <u.h>
+#include <libc.h>
+
+const char datac[] = {0,'b','w',0,'l'};
+
+void
+main(int argc, char** argv) {
+	ulong size, segsize, op, port;
+	char* segment;
+	ulong data;
+	uchar *seg;
+	
+	data = 0;
+	size = 1;
+	op = -1;
+	ARGBEGIN {
+		case 'W': size = 2; break;
+		case 'L': size = 4; break;
+		case 'r': op = OREAD; break;
+		case 'w': op = OWRITE; break;
+		default: sysfatal("bad flag %c", ARGC());
+	} ARGEND;
+	if(op == -1) sysfatal("no operation selected");
+	if(argc < 3) sysfatal("no address, no segsize or no segment selected");
+	if(op == OWRITE && argc < 4) sysfatal("no data selected");
+	segment = argv[0];
+	segsize = strtoul(argv[1], 0, 0);
+	port = strtoul(argv[2], 0, 0);
+	if(op == OWRITE) data = strtoul(argv[3], 0, 0);
+	
+	seg = segattach(0, segment, 0, segsize);
+	if(seg == (uchar*)-1) sysfatal("segattach: %r");
+	
+	if(op == OWRITE) {
+		switch(size) {
+			case 1: *(uchar*)(seg+port) = data; break;
+			case 2: *(ushort*)(seg+port) = data; break;
+			case 4: *(ulong*)(seg+port) = data; break;
+		}
+	}
+	else {
+		data = seg[port];
+		if(size >= 2) data |= seg[port+1] << 8;
+		if(size >= 4) data |= (seg[port+2] << 16) | (seg[port+3] << 24);
+		print("0x%ulx\n", data);
+	}
+}
\ No newline at end of file