From 4cbdbfe838cb791e2e3b782dac79b7512129fe15 Mon Sep 17 00:00:00 2001
From: Ruslan Isaev <ubijca16@gmail.com>
Date: Sat, 15 Mar 2025 22:33:53 +0300
Subject: [PATCH] disk: implement ata_write

---
 include/disk.h |  1 +
 src/disk.c     | 36 +++++++++++++++++++++++++++++++-----
 src/kernel.c   | 10 +---------
 3 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/include/disk.h b/include/disk.h
index 72f1f01..2635909 100644
--- a/include/disk.h
+++ b/include/disk.h
@@ -12,5 +12,6 @@ typedef struct {
 void get_disk_info(disk_info *info);
 int ide_check_disk_present();
 uint8_t ata_read(uint8_t *buffer, uint32_t lba);
+void ata_write(uint8_t *buffer, uint32_t lba);
 
 #endif
diff --git a/src/disk.c b/src/disk.c
index 8b43937..180959b 100644
--- a/src/disk.c
+++ b/src/disk.c
@@ -33,6 +33,15 @@ unsigned short ide_read_data() {
 
 #define inw ide_read_data
 
+void outw(uint16_t port, uint16_t value) //implemented in asm
+{
+    __asm__ volatile(
+        "out %0, %1"
+        :
+        : "a" (value), "Nd" (port)
+    );
+}
+
 unsigned char ide_read_status() {
     unsigned char status;
     __asm__ __volatile__("inb %1, %0" : "=a" (status) : "d" (IDE_STATUS));
@@ -154,21 +163,38 @@ void ata_poll()
 //x86 directions section
 uint8_t ata_read(uint8_t *buffer, uint32_t lba)
 {
-	outb(0x1F6, 0xE0 | ((lba >> 24) & 0x0F));
-	outb(0x1F1, 0x00);//TODO: this is probably ignored so could be removed maybe?
+	outb(0x1F6, 0xE0 | ((lba >> 24) & 0x0F));//E0 is for master, F0 is for slave
+	//outb(0x1F1, 0x00);//TODO: this is probably ignored so could be removed maybe?
 	outb(0x1F2, 1);//1 is sector count, how many sectors are we reading
 	outb(0x1F3, (unsigned char) lba);
 	outb(0x1F4, (unsigned char)(lba >> 8));
 	outb(0x1F5, (unsigned char)(lba >> 16));
 	outb(0x1F7, 0x20); //Send the "READ SECTORS" command
-	//TODO: here we do the polling yo
 	ata_poll();
 	for(int i = 0; i < 256; i++)
 	{
 		uint16_t data = inw(0x1F0);
 		*(uint16_t*)(buffer+i*2) = data;
-		//printf("data: %X\n", data);
 	}
-	//TODO: give the drive 400ns delay to reset DRQ
 	ata_400ns_delay();
 }
+
+void ata_write(uint8_t *buffer, uint32_t lba)
+{
+	outb(0x1F6, 0xE0 | ((lba >> 24) & 0x0F));
+
+	outb(0x1F2, 1);//sector count
+	outb(0x1F3, (unsigned char) lba);
+	outb(0x1F4, (unsigned char) (lba >> 8));
+	outb(0x1F5, (unsigned char) (lba >> 16));
+	outb(0x1F7, 0x30); //Send the "WRITE SECTORS" command
+	ata_poll();
+
+	for(int i = 0; i < 256; i++)
+	{
+		uint16_t data = *(uint16_t*)(buffer + i * 2);
+		outw(0x1F0, data);
+		ata_400ns_delay();
+	}
+	outb(0x1F7, 0xE7);//Cache flush
+}
diff --git a/src/kernel.c b/src/kernel.c
index e8123ad..f161a37 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -4,6 +4,7 @@
 #include "../include/stdio.h"
 #include "../include/utils.h"
 #include "../include/disk.h"
+#include "../include/string.h"
 
 #include <stdint.h>
 
@@ -17,20 +18,11 @@ void kmain()
 
 	char yooo[256] = "heheh";
 	printf("test string: %s\n", yooo);
-	printf("%X %X %X", 0x11, 0xA, 0xFEE1DEAD);
 
 	disk_info info;
 	get_disk_info(&info);
 	printf("CYL HEAD SECT: %X %X %X\n", info.cylinders, info.heads, info.sectors);
 
-	uint8_t buffer[512];
-	ata_read(buffer, 0x0);
-
-	for(int i = 0; i < sizeof(buffer); i++)
-	{
-		printf("%X ", buffer[i]);
-	}
-
 	while(1)
 	{
 		if(inportb(0x64) & 0x1)