From 3e07c636a586b877ef6f20ff6f722b3f2f59e836 Mon Sep 17 00:00:00 2001
From: Curle <curle@gemwire.uk>
Date: Fri, 16 Jul 2021 05:25:30 +0100
Subject: [PATCH] Implement PATA-IDE code

---
 src/drivers/devices/storage/ata.cpp | 120 ++++++++++++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100644 src/drivers/devices/storage/ata.cpp

diff --git a/src/drivers/devices/storage/ata.cpp b/src/drivers/devices/storage/ata.cpp
new file mode 100644
index 0000000..f54bf43
--- /dev/null
+++ b/src/drivers/devices/storage/ata.cpp
@@ -0,0 +1,120 @@
+#include <kernel/system/io.h>
+#include <lainlib/mutex/ticketlock.h>
+#include <driver/storage/ata.h>
+
+/************************
+ *** Team Kitty, 2021 ***
+ ***     Chroma       ***
+ ***********************/
+using namespace Device;
+
+// Internal storage.
+bool IRQWaiting = false;
+ticketlock_t ATALock;
+
+void ATADevice::Init() {
+    if(!HasATA()) {
+        SerialPrintf("[  ATA] No ATA device found.\r\n");
+        return;
+    }
+
+    SelectedDrive = ATAType::PRIMARY_MASTER;
+
+    WritePort(ATAAddress::PRIMARY_DCR, 0x04, 1);
+    WritePort(ATAAddress::PRIMARY_DCR, 0x00, 1);
+
+    uint8_t Status = ATACommandRead(true, ATARegister::COMMAND_STATUS);
+    while((Status & 0x80) && !(Status & 0x1)) { // While BSY && !ERR
+        Status = ATACommandRead(true, ATARegister::COMMAND_STATUS);
+    }
+}
+
+void ATADevice::HandleIRQ(size_t IRQID) {
+    if(IRQWaiting)
+        IRQWaiting = false;
+    
+    if(IRQID == 14)
+        ReadPort(PRIMARY + COMMAND_STATUS, 1);
+
+    if(IRQID == 15)
+        ReadPort(SECONDARY + COMMAND_STATUS, 1);
+}
+
+void ATADevice::ATACommandWrite(bool Primary, uint16_t Register, uint16_t Data) {
+    WritePort((Primary ? PRIMARY : SECONDARY) + Register, Data, 2);
+}
+
+uint16_t ATADevice::ATACommandRead(bool Primary, uint16_t Register) {
+    return ReadPort((Primary ? PRIMARY : SECONDARY) + Register, 2);
+}
+
+bool ATADevice::GetStatus() {
+    uint8_t Status = ATACommandRead(true, COMMAND_STATUS);
+    while((Status & 0x80) && !(Status & 0x8)) { // While BSY && !DRQ
+        Status = ATACommandRead(true, COMMAND_STATUS);
+    }
+    return true;
+}
+
+bool ATADevice::HasATA() {
+    // https://wiki.osdev.org/ATA_PIO_Mode#IDENTIFY_command
+    ATACommandWrite(true, SECTOR_COUNT, 0);
+    ATACommandWrite(true, LBA0, 0);
+    ATACommandWrite(true, LBA1, 0);
+    ATACommandWrite(true, LBA2, 0);
+    ATACommandWrite(true, COMMAND_STATUS, IDENTIFY);
+
+    uint8_t Status = ATACommandRead(true, COMMAND_STATUS);
+    if(Status == 0)
+        return false;
+    
+    // TODO: ATAPI weirdness
+    return true;
+}
+
+void ATADevice::ReadData(size_t Address, size_t Length, uint8_t* Buffer) {
+    TicketAttemptLock(&ATALock);
+    IRQWaiting = true;
+
+    ATACommandWrite(true, SELECTOR, 0x40 | 0xE0);
+    ATACommandWrite(true, ERROR_FEATURE, 0);
+    
+    ATACommandWrite(true, SECTOR_COUNT, Length >> 8);
+    ATACommandWrite(true, LBA0, (uint8_t)(Address >> 24));
+    ATACommandWrite(true, LBA1, (uint8_t)(Address >> 32));
+    ATACommandWrite(true, LBA2, (uint8_t)(Address >> 40));
+    
+    ATACommandWrite(true, SECTOR_COUNT, Length);
+    ATACommandWrite(true, LBA0, (uint8_t)(Address));
+    ATACommandWrite(true, LBA1, (uint8_t)(Address >> 8));
+    ATACommandWrite(true, LBA2, (uint8_t)(Address >> 16));
+    
+    ATACommandWrite(true, COMMAND_STATUS, READ);
+
+    Wait(5);
+
+    size_t Counter = Length;
+    size_t Offset = 0;
+
+    while(Counter--) {
+        Wait(5);
+        size_t Status = Spinlock();
+        
+        if((Status & 0x1) || (Status & 0x20)) {
+            Wait(5);
+
+            uint8_t Error = ATACommandRead(true, ERROR_FEATURE);
+            SerialPrintf("[  ATA] Logged error %d.\r\n", Error);
+            TicketUnlock(&ATALock);
+            return;
+        }
+
+        for(uint16_t i = 0; i < 256; i++)
+            *((unsigned short*) Buffer + (Offset + i)) = ATACommandRead(true, DATA);
+        
+        Offset += 256;
+    }
+
+    TicketUnlock(&ATALock);
+    return;
+}
\ No newline at end of file