1 files changed, 73 insertions, 0 deletions
diff --git a/src/loader/ide.c b/src/loader/ide.c
new file mode 100644
index 0000000..f279bc2
--- /dev/null
+++ b/src/loader/ide.c
@@ -0,0 +1,73 @@
+// MIT License, Copyright (c) 2021 Marvin Borner
+
+#include <cpu.h>
+#include <def.h>
+#include <ide.h>
+#include <log.h>
+
+static u8 ide_buf[SECTOR_SIZE] = { 0 };
+
+static void ide_select_drive(u8 bus, u8 drive)
+{
+	if (bus == ATA_PRIMARY) {
+		if (drive == ATA_MASTER)
+			outb(ATA_PRIMARY_IO + ATA_REG_HDDEVSEL, 0xa0);
+		else
+			outb(ATA_PRIMARY_IO + ATA_REG_HDDEVSEL, 0xb0);
+	} else {
+		if (drive == ATA_MASTER)
+			outb(ATA_SECONDARY_IO + ATA_REG_HDDEVSEL, 0xa0);
+		else
+			outb(ATA_SECONDARY_IO + ATA_REG_HDDEVSEL, 0xb0);
+	}
+}
+
+static u8 ide_find(u8 bus, u8 drive)
+{
+	u16 io = bus == ATA_PRIMARY ? ATA_PRIMARY_IO : ATA_SECONDARY_IO;
+	ide_select_drive(bus, drive);
+
+	// Reset
+	outb(io + ATA_REG_SECCOUNT0, 0);
+	outb(io + ATA_REG_LBA0, 0);
+	outb(io + ATA_REG_LBA1, 0);
+	outb(io + ATA_REG_LBA2, 0);
+
+	// Identify
+	outb(io + ATA_REG_COMMAND, ATA_CMD_IDENTIFY);
+	u8 status = inb(io + ATA_REG_STATUS);
+	if (!status)
+		return 0;
+
+	while ((inb(io + ATA_REG_STATUS) & ATA_SR_BSY) != 0)
+		;
+
+	do {
+		status = inb(io + ATA_REG_STATUS);
+		if (status & ATA_SR_ERR)
+			return 0;
+	} while ((status & ATA_SR_DRQ) == 0);
+
+	for (int i = 0; i < BLOCK_COUNT; i++)
+		*(u16 *)(ide_buf + i * 2) = inw(io + ATA_REG_DATA);
+
+	return 1;
+}
+
+static void ata_probe(void)
+{
+	for (u8 i = 0; i < 4; i++) {
+		u32 bus = i < 2 ? ATA_PRIMARY : ATA_SECONDARY;
+		u32 drive = i % 2 ? ATA_MASTER : ATA_SLAVE;
+
+		if (!ide_find(bus, drive))
+			continue;
+
+		log("[IDE] Found hd%c\n", 'a' + i);
+	}
+}
+
+void ata_install(void)
+{
+	ata_probe();
+}