checkpoint

1 files changed, 117 insertions, 0 deletions

diff --git a/ide.c b/ide.c
new file mode 100644
index 0000000..3152f93
--- /dev/null
+++ b/ide.c
@@ -0,0 +1,117 @@
+/*
+ * Minimal PIO-based (non-interrupt-driven) IDE driver code.
+ * For information about what all this IDE/ATA magic means,
+ * see the materials available on the class references page.
+ */
+
+#include "types.h"
+#include "param.h"
+#include "mmu.h"
+#include "proc.h"
+#include "defs.h"
+#include "x86.h"
+
+#define IDE_BSY		0x80
+#define IDE_DRDY	0x40
+#define IDE_DF		0x20
+#define IDE_ERR		0x01
+
+static int diskno = 0;
+
+static int
+ide_wait_ready(int check_error)
+{
+	int r;
+
+	while (((r = inb(0x1F7)) & (IDE_BSY|IDE_DRDY)) != IDE_DRDY)
+		/* do nothing */;
+
+	if (check_error && (r & (IDE_DF|IDE_ERR)) != 0)
+		return -1;
+	return 0;
+}
+
+int
+ide_probe_disk1(void)
+{
+	int r, x;
+
+	// wait for Device 0 to be ready
+	ide_wait_ready(0);
+
+	// switch to Device 1
+	outb(0x1F6, 0xE0 | (1<<4));
+
+	// check for Device 1 to be ready for a while
+	for (x = 0; x < 1000 && (r = inb(0x1F7)) == 0; x++)
+		/* do nothing */;
+
+	// switch back to Device 0
+	outb(0x1F6, 0xE0 | (0<<4));
+
+	cprintf("Device 1 presence: %d\n", (x < 1000));
+	return (x < 1000);
+}
+
+void
+ide_set_disk(int d)
+{
+	if (d != 0 && d != 1)
+		panic("bad disk number");
+	diskno = d;
+}
+
+int
+ide_read(uint32_t secno, void *dst, unsigned nsecs)
+{
+	int r;
+
+        if(nsecs > 256)
+          panic("ide_read");
+
+	ide_wait_ready(0);
+
+        outb(0x3f6, 0);
+	outb(0x1F2, nsecs);
+	outb(0x1F3, secno & 0xFF);
+	outb(0x1F4, (secno >> 8) & 0xFF);
+	outb(0x1F5, (secno >> 16) & 0xFF);
+	outb(0x1F6, 0xE0 | ((diskno&1)<<4) | ((secno>>24)&0x0F));
+	outb(0x1F7, 0x20);	// CMD 0x20 means read sector
+        
+        sleep(0);
+
+	for (; nsecs > 0; nsecs--, dst += 512) {
+		if ((r = ide_wait_ready(1)) < 0)
+			return r;
+		insl(0x1F0, dst, 512/4);
+	}
+	
+	return 0;
+}
+
+int
+ide_write(uint32_t secno, const void *src, unsigned nsecs)
+{
+	int r;
+	
+        if(nsecs > 256)
+          panic("ide_write");
+
+	ide_wait_ready(0);
+
+	outb(0x1F2, nsecs);
+	outb(0x1F3, secno & 0xFF);
+	outb(0x1F4, (secno >> 8) & 0xFF);
+	outb(0x1F5, (secno >> 16) & 0xFF);
+	outb(0x1F6, 0xE0 | ((diskno&1)<<4) | ((secno>>24)&0x0F));
+	outb(0x1F7, 0x30);	// CMD 0x30 means write sector
+
+	for (; nsecs > 0; nsecs--, src += 512) {
+		if ((r = ide_wait_ready(1)) < 0)
+			return r;
+		outsl(0x1F0, src, 512/4);
+	}
+
+	return 0;
+}