From 5da2476852f5f70bd10f8640c80f9d5ce3fb1bac Mon Sep 17 00:00:00 2001
From: Tom-on64 <kubecekt@gmail.com>
Date: Thu, 11 Apr 2024 12:25:38 +0200
Subject: [PATCH] Fixed diskRead() function and made it follow the defined
 standards. \nAlso made a temp fix to the disk.c issue (it's something about
 the disk.o obj file idk

---
 build.sh            |  7 ++++---
 src/kernel/disk.c   | 31 +++++++++++++++++++++++++++++++
 src/kernel/disk.h   |  4 ++--
 src/kernel/f_disk.c | 27 ---------------------------
 4 files changed, 37 insertions(+), 32 deletions(-)
 create mode 100644 src/kernel/disk.c
 delete mode 100644 src/kernel/f_disk.c

diff --git a/build.sh b/build.sh
index 5595d9c..96cad86 100644
--- a/build.sh
+++ b/build.sh
@@ -12,14 +12,15 @@ nasm -fbin ./src/boot.asm -o ./build/boot.bin
 echo "Assembling ./src/kernel/entry.asm..."
 nasm -felf32 ./src/kernel/entry.asm -o ./build/entry.o
 
-for file in ./src/kernel/**.c; do
+for file in ./src/kernel/*.c; do
     filename=$(basename "$file" .c)
     echo "Compiling $file..."
-    i386-elf-gcc -ffreestanding -Wall -Wextra -m32 -c $file -o ./build/$filename.o
+    i386-elf-gcc -ffreestanding -Wall -Wextra -m32 -c "$file" -o "./build/$filename.o"
 done
 
 echo "Linking kernel object files..."
-i386-elf-ld -o ./build/kernel.bin -Ttext 0x1000 --oformat binary ./build/**.o
+mv ./build/disk.o ./build/f_disk.o # Very temporary fix to issue with disk.o not linking or something weird
+i386-elf-ld -o ./build/kernel.bin -Ttext 0x1000 --oformat binary ./build/*.o
 
 # OS Image
 echo "Creating kern.iso disk image..."
diff --git a/src/kernel/disk.c b/src/kernel/disk.c
new file mode 100644
index 0000000..fcd76e6
--- /dev/null
+++ b/src/kernel/disk.c
@@ -0,0 +1,31 @@
+#include "disk.h"
+#include "stdint.h"
+#include "system.h"
+
+#define PIO_PORT 0x1f0
+#define READ_COMMAND 0x20
+#define WRITE_COMMAND 0x30
+
+void diskRead(uint32_t lbaAddress, uint8_t sectorCount, char* dst) {
+    outb(PIO_PORT + 6, ((lbaAddress >> 24) & 0x0f) | 0xe0); // 6 - Use LBA; 4 - Drive number; 3-0 - Highest lba address nibble
+    outb(PIO_PORT + 2, sectorCount); // Sector count register
+    outb(PIO_PORT + 3, (uint8_t)(lbaAddress)); // Lowest lba address byte
+    outb(PIO_PORT + 4, (uint8_t)(lbaAddress >> 8)); // Middle lba address byte
+    outb(PIO_PORT + 5, (uint8_t)(lbaAddress >> 16)); // High lba address byte
+    outb(PIO_PORT + 7, READ_COMMAND); // Command register
+    
+    uint16_t* address = (uint16_t*)dst;
+
+    for (uint8_t i = sectorCount; i > 0; i--) {
+        while (inb(PIO_PORT + 7) & (1 << 7)); // Poll status register untill BSY bit is clear
+
+        for (size_t j = 0; j < 256; j++) {
+            *address++ = inw(PIO_PORT); // Read 256 words (512 Bytes = 1 Sector)
+        }
+
+        for (uint8_t delay = 0; delay < 4; delay++) { // 400ns delay
+            inb(0x3f6); // Alternate status register
+        }
+    }
+}
+
diff --git a/src/kernel/disk.h b/src/kernel/disk.h
index e64460b..e8e86d9 100644
--- a/src/kernel/disk.h
+++ b/src/kernel/disk.h
@@ -5,7 +5,7 @@
 
 extern uint8_t driveNum;
 
-void diskRead(uint8_t sector, uint8_t sectorCount, uint8_t drive, char* dst);
-void diskWrite(uint8_t sector, uint8_t sectorCount, uint8_t drive, const char* src);
+void diskRead(uint32_t lbaAddress, uint8_t sectorCount, char* dst);
+// TODO: void diskWrite(uint8_t sector, uint8_t sectorCount, uint8_t drive, const char* src);
 
 #endif
diff --git a/src/kernel/f_disk.c b/src/kernel/f_disk.c
deleted file mode 100644
index 8f0b73b..0000000
--- a/src/kernel/f_disk.c
+++ /dev/null
@@ -1,27 +0,0 @@
-#include "disk.h"
-#include "stdint.h"
-#include "system.h"
-
-#define PIO_PORT 0x1f0
-
-void diskRead(uint8_t sector, uint8_t sectorCount, uint8_t drive, char* dst) {
-    outb(PIO_PORT + 6, (drive & 0x0f) | 0xa0); // Head and drive number port
-    outb(PIO_PORT + 2, sectorCount); // Sector count
-    outb(PIO_PORT + 3, sector); // Sector to start reading at
-    outb(PIO_PORT + 4, 0); // Cylinder number low
-    outb(PIO_PORT + 5, 0); // Cylinder number high
-    outb(PIO_PORT + 7, 0x20); // Command register, 0x20 - Read with retry
-    
-    while (inb(PIO_PORT + 7) == 8); // Status register, wait until ready
-
-    uint32_t i = 512 * sectorCount;
-    while (i > 0) {
-        uint16_t data = inw(PIO_PORT); // Data port
-        *dst++ = (uint8_t)(data);
-        *dst++ = (uint8_t)(data >> 8);
-        i--;
-    }
-}
-
-void diskWrite(uint8_t sector, uint8_t sectorCount, uint8_t drive, const char* src);
-