Added *very* simple ide and ext2 support

2 files changed, 49 insertions, 0 deletions

diff --git a/src/drivers/cpu.c b/src/drivers/cpu.c
index 22691fb..d6a1760 100644
--- a/src/drivers/cpu.c
+++ b/src/drivers/cpu.c
@@ -24,6 +24,14 @@ u32 inl(u16 port)
 	return value;
 }
 
+void insl(u16 port, void *addr, int n)
+{
+	__asm__("cld; rep insl"
+		: "=D"(addr), "=c"(n)
+		: "d"(port), "0"(addr), "1"(n)
+		: "memory", "cc");
+}
+
 void outb(u16 port, u8 data)
 {
 	__asm__("outb %0, %1" ::"a"(data), "Nd"(port));
diff --git a/src/drivers/ide.c b/src/drivers/ide.c
new file mode 100644
index 0000000..fe3955c
--- /dev/null
+++ b/src/drivers/ide.c
@@ -0,0 +1,41 @@
+// MIT License, Copyright (c) 2020 Marvin Borner
+
+#include <cpu.h>
+#include <def.h>
+#include <ide.h>
+
+int ide_wait(int check)
+{
+	char r;
+
+	// Wait while drive is busy. Once just ready is set, exit the loop
+	while (((r = (char)inb(IDE_IO | IDE_CMD)) & (IDE_BUSY | IDE_READY)) != IDE_READY)
+		;
+
+	// Check for errors
+	if (check && (r & (IDE_DRIVE_FAULT | IDE_ERROR)) != 0)
+		return 0xF;
+	return 0;
+}
+
+void *ide_read(void *b, u32 block)
+{
+	int sector_per_block = BLOCK_SIZE / SECTOR_SIZE; // 2
+	int sector = block * sector_per_block;
+
+	ide_wait(0);
+	outb(IDE_IO | IDE_SECTOR_COUNT, sector_per_block); // Number of sectors
+	outb(IDE_IO | IDE_LOW, LBA_LOW(sector));
+	outb(IDE_IO | IDE_MID, LBA_MID(sector));
+	outb(IDE_IO | IDE_HIGH, LBA_HIGH(sector));
+
+	// Slave/Master << 4 and last 4 bits
+	outb(IDE_IO | IDE_HEAD, 0xE0 | (1 << 4) | LBA_LAST(sector));
+	outb(IDE_IO | IDE_CMD, IDE_CMD_READ);
+	ide_wait(0);
+
+	// Read-only
+	insl(IDE_IO, b, BLOCK_SIZE / 4);
+
+	return b;
+}