5650 - support a second OS: soso

https://github.com/ozkl/soso

+ Much smaller than Linux; builds instantly
+ Supports graphics
- No network support
- Doesn't work on a cloud server (yet?)

1 files changed, 211 insertions, 0 deletions

diff --git a/kernel.soso/descriptortables.c b/kernel.soso/descriptortables.c
new file mode 100644
index 00000000..258e33c6
--- /dev/null
+++ b/kernel.soso/descriptortables.c
@@ -0,0 +1,211 @@
+#include "screen.h"
+#include "common.h"
+#include "descriptortables.h"
+#include "isr.h"
+#include "process.h"
+
+extern void flushGdt(uint32);
+extern void flushIdt(uint32);
+extern void flushTss();
+
+
+static void initializeGdt();
+static void initializeIdt();
+static void setGdtEntry(int32 num, uint32 base, uint32 limit, uint8 access, uint8 gran);
+static void setIdtEntry(uint8 num, uint32 base, uint16 sel, uint8 flags);
+
+GdtEntry gGdtEntries[6];
+GdtPointer   gGdtPointer;
+IdtEntry gIdtEntries[256];
+IdtPointer   gIdtPointer;
+Tss 		gTss;
+
+extern IsrFunction gInterruptHandlers[];
+
+static void handleDoubleFault(Registers *regs);
+static void handleGeneralProtectionFault(Registers *regs);
+
+void initializeDescriptorTables()
+{
+    initializeGdt();
+
+    initializeIdt();
+
+    memset((uint8*)&gInterruptHandlers, 0, sizeof(IsrFunction)*256);
+
+    registerInterruptHandler(8, handleDoubleFault);
+    registerInterruptHandler(13, handleGeneralProtectionFault);
+}
+
+static void initializeGdt()
+{
+    gGdtPointer.limit = (sizeof(GdtEntry) * 6) - 1;
+    gGdtPointer.base  = (uint32)&gGdtEntries;
+
+    setGdtEntry(0, 0, 0, 0, 0);                // 0x00 Null segment
+    setGdtEntry(1, 0, 0xFFFFFFFF, 0x9A, 0xCF); // 0x08 Code segment
+    setGdtEntry(2, 0, 0xFFFFFFFF, 0x92, 0xCF); // 0x10 Data segment
+    setGdtEntry(3, 0, 0xFFFFFFFF, 0xFA, 0xCF); // 0x18 User mode code segment
+    setGdtEntry(4, 0, 0xFFFFFFFF, 0xF2, 0xCF); // 0x20 User mode data segment
+
+    //TSS
+    memset((uint8*)&gTss, 0, sizeof(gTss));
+    gTss.debug_flag = 0x00;
+    gTss.io_map = 0x00;
+    gTss.esp0 = 0;//0x1FFF0;
+    gTss.ss0 = 0x10;//0x18;
+
+    gTss.cs   = 0x0B; //from ring 3 - 0x08 | 3 = 0x0B
+    gTss.ss = gTss.ds = gTss.es = gTss.fs = gTss.gs = 0x13; //from ring 3 = 0x10 | 3 = 0x13
+    uint32 tss_base = (uint32) &gTss;
+    uint32 tss_limit = tss_base + sizeof(gTss);
+    setGdtEntry(5, tss_base, tss_limit, 0xE9, 0x00);
+
+    flushGdt((uint32)&gGdtPointer);
+    flushTss();
+}
+
+// Set the value of one GDT entry.
+static void setGdtEntry(int32 num, uint32 base, uint32 limit, uint8 access, uint8 gran)
+{
+    gGdtEntries[num].base_low    = (base & 0xFFFF);
+    gGdtEntries[num].base_middle = (base >> 16) & 0xFF;
+    gGdtEntries[num].base_high   = (base >> 24) & 0xFF;
+
+    gGdtEntries[num].limit_low   = (limit & 0xFFFF);
+    gGdtEntries[num].granularity = (limit >> 16) & 0x0F;
+    
+    gGdtEntries[num].granularity |= gran & 0xF0;
+    gGdtEntries[num].access      = access;
+}
+
+void irqTimer();
+
+static void initializeIdt()
+{
+    gIdtPointer.limit = sizeof(IdtEntry) * 256 -1;
+    gIdtPointer.base  = (uint32)&gIdtEntries;
+
+    memset((uint8*)&gIdtEntries, 0, sizeof(IdtEntry)*256);
+
+    // Remap the irq table.
+    outb(0x20, 0x11);
+    outb(0xA0, 0x11);
+    outb(0x21, 0x20);
+    outb(0xA1, 0x28);
+    outb(0x21, 0x04);
+    outb(0xA1, 0x02);
+    outb(0x21, 0x01);
+    outb(0xA1, 0x01);
+    outb(0x21, 0x0);
+    outb(0xA1, 0x0);
+
+    setIdtEntry( 0, (uint32)isr0 , 0x08, 0x8E);
+    setIdtEntry( 1, (uint32)isr1 , 0x08, 0x8E);
+    setIdtEntry( 2, (uint32)isr2 , 0x08, 0x8E);
+    setIdtEntry( 3, (uint32)isr3 , 0x08, 0x8E);
+    setIdtEntry( 4, (uint32)isr4 , 0x08, 0x8E);
+    setIdtEntry( 5, (uint32)isr5 , 0x08, 0x8E);
+    setIdtEntry( 6, (uint32)isr6 , 0x08, 0x8E);
+    setIdtEntry( 7, (uint32)isr7 , 0x08, 0x8E);
+    setIdtEntry( 8, (uint32)isr8 , 0x08, 0x8E);
+    setIdtEntry( 9, (uint32)isr9 , 0x08, 0x8E);
+    setIdtEntry(10, (uint32)isr10, 0x08, 0x8E);
+    setIdtEntry(11, (uint32)isr11, 0x08, 0x8E);
+    setIdtEntry(12, (uint32)isr12, 0x08, 0x8E);
+    setIdtEntry(13, (uint32)isr13, 0x08, 0x8E);
+    setIdtEntry(14, (uint32)isr14, 0x08, 0x8E);
+    setIdtEntry(15, (uint32)isr15, 0x08, 0x8E);
+    setIdtEntry(16, (uint32)isr16, 0x08, 0x8E);
+    setIdtEntry(17, (uint32)isr17, 0x08, 0x8E);
+    setIdtEntry(18, (uint32)isr18, 0x08, 0x8E);
+    setIdtEntry(19, (uint32)isr19, 0x08, 0x8E);
+    setIdtEntry(20, (uint32)isr20, 0x08, 0x8E);
+    setIdtEntry(21, (uint32)isr21, 0x08, 0x8E);
+    setIdtEntry(22, (uint32)isr22, 0x08, 0x8E);
+    setIdtEntry(23, (uint32)isr23, 0x08, 0x8E);
+    setIdtEntry(24, (uint32)isr24, 0x08, 0x8E);
+    setIdtEntry(25, (uint32)isr25, 0x08, 0x8E);
+    setIdtEntry(26, (uint32)isr26, 0x08, 0x8E);
+    setIdtEntry(27, (uint32)isr27, 0x08, 0x8E);
+    setIdtEntry(28, (uint32)isr28, 0x08, 0x8E);
+    setIdtEntry(29, (uint32)isr29, 0x08, 0x8E);
+    setIdtEntry(30, (uint32)isr30, 0x08, 0x8E);
+    setIdtEntry(31, (uint32)isr31, 0x08, 0x8E);
+
+    setIdtEntry(32, (uint32)irqTimer, 0x08, 0x8E);
+    setIdtEntry(33, (uint32)irq1, 0x08, 0x8E);
+    setIdtEntry(34, (uint32)irq2, 0x08, 0x8E);
+    setIdtEntry(35, (uint32)irq3, 0x08, 0x8E);
+    setIdtEntry(36, (uint32)irq4, 0x08, 0x8E);
+    setIdtEntry(37, (uint32)irq5, 0x08, 0x8E);
+    setIdtEntry(38, (uint32)irq6, 0x08, 0x8E);
+    setIdtEntry(39, (uint32)irq7, 0x08, 0x8E);
+    setIdtEntry(40, (uint32)irq8, 0x08, 0x8E);
+    setIdtEntry(41, (uint32)irq9, 0x08, 0x8E);
+    setIdtEntry(42, (uint32)irq10, 0x08, 0x8E);
+    setIdtEntry(43, (uint32)irq11, 0x08, 0x8E);
+    setIdtEntry(44, (uint32)irq12, 0x08, 0x8E);
+    setIdtEntry(45, (uint32)irq13, 0x08, 0x8E);
+    setIdtEntry(46, (uint32)irq14, 0x08, 0x8E);
+    setIdtEntry(47, (uint32)irq15, 0x08, 0x8E);
+    setIdtEntry(128, (uint32)isr128, 0x08, 0x8E);
+
+    flushIdt((uint32)&gIdtPointer);
+}
+
+static void setIdtEntry(uint8 num, uint32 base, uint16 sel, uint8 flags)
+{
+    gIdtEntries[num].base_lo = base & 0xFFFF;
+    gIdtEntries[num].base_hi = (base >> 16) & 0xFFFF;
+
+    gIdtEntries[num].sel     = sel;
+    gIdtEntries[num].always0 = 0;
+    gIdtEntries[num].flags   = flags  | 0x60;
+}
+
+static void handleDoubleFault(Registers *regs)
+{
+    printkf("Double fault!!! Error code:%d\n", regs->errorCode);
+
+    PANIC("Double fault!!!");
+}
+
+static void handleGeneralProtectionFault(Registers *regs)
+{
+    printkf("General protection fault!!! Error code:%d - IP:%x\n", regs->errorCode, regs->eip);
+
+    Thread* faultingThread = getCurrentThread();
+    if (NULL != faultingThread)
+    {
+        Thread* mainThread = getMainKernelThread();
+
+        if (mainThread == faultingThread)
+        {
+            PANIC("General protection fault in Kernel main thread!!!");
+        }
+        else
+        {
+            printkf("Faulting thread is %d\n", faultingThread->threadId);
+
+            if (faultingThread->userMode)
+            {
+                printkf("Destroying process %d\n", faultingThread->owner->pid);
+
+                destroyProcess(faultingThread->owner);
+            }
+            else
+            {
+                printkf("Destroying kernel thread %d\n", faultingThread->threadId);
+
+                destroyThread(faultingThread);
+            }
+
+            waitForSchedule();
+        }
+    }
+    else
+    {
+        PANIC("General protection fault!!!");
+    }
+}