lapic bus speed probing and starting switch to ioapic

7 files changed, 88 insertions, 51 deletions

diff --git a/README.md b/README.md
index efd3a29..207957c 100644
--- a/README.md
+++ b/README.md
@@ -98,6 +98,8 @@ Discontinued Features
 Todos
 -----
 
+* ipxe (network drivers?)
+* io_wait?
 * cpuid (i686) check apic?
 * lapic / spurious . ioapic
 * newlib reentrant struct!!
diff --git a/asm/asm_pic.asm b/asm/asm_pic.asm
index 2514be7..8a90fdf 100644
--- a/asm/asm_pic.asm
+++ b/asm/asm_pic.asm
@@ -78,6 +78,12 @@ in	al, 0xA1		; read in the primary PIC Interrupt Mask Register (IMR)
 and	al, 0x00		; 0xEF => 11101111b. This sets the IRQ4 bit (Bit 5) in AL
 out	0xA1, al		; write the value back into IMR
 
+;disable
+
+;mov al, 0xff
+;out 0xa1, al
+;out 0x21, al
+
 ret
 
 ;;;;;;;;;;;;;;;;;;;;
diff --git a/asm/asm_pit.s b/asm/asm_pit.s
index 8be29cb..28fd784 100644
--- a/asm/asm_pit.s
+++ b/asm/asm_pit.s
@@ -49,7 +49,7 @@ asm_pit_tick:
 
 .macro asm_pit_sleep val
 
-    mov $0x00110000, %al // chan 0 / mode 0
+    mov $0b00110000, %al // chan 0 / mode 0
     outb %al,$0x43
     
     // LSB first
@@ -57,18 +57,20 @@ asm_pit_tick:
     out %al, $0x40
     xchg %ah,%al
     out %al, $0x40
-    
-    // check if finished
-    mov $0xE2, %al 
-    outb %al,$0x43
 
     //sleep until finished
-    //7th bit determines if finished
+    //7th bit (0-7) determines if finished
     sleep\val:
-    inb $0x40, %al
-    or  $0b1000000, %al
-    cmp $0b1000000, %al 
-    jne sleep\val
+
+	// read back command
+	mov $0b11100010, %al 
+	outb %al,$0x43
+
+	inb $0x40, %al
+	and  $0b10000000, %al
+
+	cmp $0b10000000, %al 
+	jne sleep\val
 
     ret
 
diff --git a/kernel/gdt.c b/kernel/gdt.c
index 0657387..bf8f203 100644
--- a/kernel/gdt.c
+++ b/kernel/gdt.c
@@ -7,7 +7,8 @@
 #define GDT_SIZE 6
 
 //https://wiki.osdev.org/Task_State_Segment
-tss_struct sys_tss[SMP_MAX_PROC]; //Define the TSS as a global structure
+//Define the TSS as a global structure, boah TODO: move to own page?
+tss_struct sys_tss[SMP_MAX_PROC]; 
 
 void install_tss(uint32_t cpu,uint32_t esp0){
 
@@ -19,6 +20,7 @@ void install_tss(uint32_t cpu,uint32_t esp0){
     // now set the IO bitmap (not necessary, so set above limit)       
     // sys_tss.iomap = ( unsigned short ) sizeof( tss_struct ); 
 }
+
 typedef struct GDT_struct
 {
     uint32_t base;
@@ -150,6 +152,7 @@ void gdt_init()
     setup_gdt(gdt_struct);
 
 }
+
 void setup_gdt(uint8_t *gdt_struct)
 {
     asm_setup_gdt(&gdt_struct[0],8*GDT_SIZE);
diff --git a/kernel/interrupts.c b/kernel/interrupts.c
index acf781d..30d8994 100644
--- a/kernel/interrupts.c
+++ b/kernel/interrupts.c
@@ -59,7 +59,7 @@ uint32_t interrupt_handler(uint32_t esp, uint32_t irq)
 {
 
     // DO NOT WRITE INSIDE INTERRUPTS!! COZ IT ACQUIRES LOCK AND WE WILL DEADLOCK
-//    klog("int: %d on 0x%x",irq,apicID());
+    //klog("int: %d on 0x%x",irq,apicID());
     if(irq==0)asm_pit_tick();  
 
     // mouse and kb
diff --git a/kernel/kernel.c b/kernel/kernel.c
index 17bf9b7..e20d2e1 100644
--- a/kernel/kernel.c
+++ b/kernel/kernel.c
@@ -25,12 +25,13 @@ void kernel_main(uint32_t eax,uint32_t ebx)
     serial_init();
     klog("FOOL-OS ver-%s (%s)",GIT_REVISION,__DATE__);
 
-    //    while(1);
+    klog("Global Descriptor Table (GDT) init ...");
+    gdt_init();
 
     klog("Interrupt Vector Table (IVT) init ...");
     interrupts_init(0x08);
 
-    klog("Setting up PIC");
+    klog("Remapping & (not yet Disabling) PIC ...");
     asm_pic_setup();
 
     klog("Keyboard init ...");
@@ -39,24 +40,27 @@ void kernel_main(uint32_t eax,uint32_t ebx)
     klog("Mouse init ...");
     mouse_init();
 
-    klog("Global Descriptor Table (GDT) init ...");
-    gdt_init();
-
-    klog("Multiboot Structures init ... ");
+    // gather some info (before we start paging)
+    klog("Search / Read Multiboot Structures ... ");
     multiboot_information *info;
     info=get_multiboot(eax, ebx);
     
+    klog("Search / Read ACPI Structures... ");
+    smp_processors procdata;    
+    bool acpi_found=acpi_find(&procdata);
+
+    klog("Search / Read MP Structures... ");
+    smp_processors procdata2;    
+    bool mp_found=mp_find(&procdata2);
+    //
+
+    // memory management
     klog("Memory init ... ");
     uint32_t kernel_blocks=mem_init(info);
     
-    klog("Symmetrical Multi Processing (SMP) init ... ");
-    smp_processors procdata;    
-    if(!acpi_find(&procdata))
-	if(!mp_find(&procdata))kpanic("No ACPI and no MP found!");
-
-    // searching for ACPI etc.. in physical mem has to be performed before that.
     klog("Vritual Memory / Paging init ... ");
     pdirectory *dir=vmem_init(kernel_blocks,(uint32_t)info->framebuffer_addr,procdata.local_apic_address);
+    //
     
     klog("Ram Filesystem init ... ");
     fs_mount(info);
@@ -81,16 +85,12 @@ void kernel_main(uint32_t eax,uint32_t ebx)
     uint64_t unixtime=timer_init();
     klog("Unix Time = %u seconds)",unixtime);
 
-    klog("Setting Interrupt Flag on BSP ...");
+    klog("Enable Interrupts & Unlock application processors ... ");
     asm_smp_unlock();
-    x86_sti(); // this will start processing hardware interrupts.
-
-    // TODO : pray that this is reached BEFORE scheduler kicks in!?
-
-    klog("Unlock application processors ... ");
+    // TODO : bsp sti needs to happen before ap sti? seriously? why? is this guaranteed now?
+    // TODO: switch to ioapic
+    x86_sti(); // this will start processing hardware interrupts
 
-    while(1){  // now just wait until our scheduler kicks in.
-//	klog("bsp");
-	asm("hlt");
-    }
+    // now just wait until our scheduler kicks in.
+    while(1)asm("hlt");
 }
diff --git a/kernel/smp.c b/kernel/smp.c
index da91148..b2ce6b0 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -43,6 +43,7 @@ volatile uint8_t proc;
 uint32_t cpu_counter[SMP_MAX_PROC];
 
 uint32_t local_apic_addr;
+uint32_t countdown;
 
 void writeAPIC(uint32_t offset, uint32_t value)
 {
@@ -81,6 +82,35 @@ void apicEnable()
 
 }
 
+/** select mode : divisor.
+ * 0 - 1
+ * 1 - 2
+ * 2 - 4
+ * 3 - 8
+ * 4 - 16
+ * 5 - 32
+ * 6 - 64
+ * 7 - 128
+ */
+
+uint32_t probeBusSpeed(uint32_t sel)
+{
+    uint32_t div[]={1,2,4,8,16,32,64,128};
+    uint32_t reg[]={0b1011,0,1,2,3,0b1000,0b1001,0b1010};
+
+    uint32_t divisor=div[sel];
+
+    klog("Probing bus speed for 50ms (div=%d)) ...",divisor);
+    writeAPIC(APIC_TMRDIV, reg[sel]);
+    writeAPIC(APIC_TMRINITCNT, 0xFFFFFFFF);
+//    for(int i=0;i<20;i++)
+	asm_pit_sleep_50ms();
+    //writeAPIC(APIC_LVT_TMR, APIC_LVT_INT_MASKED); //??
+    uint32_t ticksInS = 0xFFFFFFFF - readAPIC(APIC_TMRCURRCNT);
+    ticksInS*=20; // adjust to one full second.
+    klog("%d MHz (%d Hz) bus speed (ticks=%d)",ticksInS/(1000000/divisor),ticksInS*divisor,ticksInS/20);
+    return ticksInS*divisor;
+}
 void smp_main()
 {
     // setup stack
@@ -99,7 +129,6 @@ void kernel_ap()
     int_install();
     gdt_init();
     
-    uint32_t countdown=0x0fffffff; // TODO: calc to be constant, depending on bus speed. (use pit for measurement?)
     writeAPIC(APIC_TMRDIV, 0x3);
     writeAPIC(APIC_LVT_TMR, 200 | TMR_PERIODIC);
     writeAPIC(APIC_TMRINITCNT, countdown);
@@ -151,9 +180,18 @@ void smp_start_aps(smp_processors *pros)
 {
         // TODO: check if local APIC is present via CPUID (P6 (i686) and above)
 	local_apic_addr=pros->local_apic_address;
-
 	klog("bsp local apic id: 0x%08X",apicID());
 
+	apicEnable(); // bsp apic seems to be enabled anyway.
+
+	uint32_t speed=probeBusSpeed(4); // get bus speed (divisor: 16)
+
+	// setup apic timer
+	countdown=speed/16; // tick once a second
+	writeAPIC(APIC_TMRDIV, 0x3); // divisor 16
+	writeAPIC(APIC_LVT_TMR, 200 | TMR_PERIODIC); // on interrupt 200
+	writeAPIC(APIC_TMRINITCNT, countdown);
+
         for(int i=0;i<pros->processors;i++)
 	{
 	    if(pros->boot==i)continue;
@@ -177,19 +215,5 @@ void smp_start_aps(smp_processors *pros)
 	    // TODO retry 110 SIPI with 1s timeout
 	    
 	}
-
-    apicEnable(); // bsp seems to be enabled anyway.
-    
-    writeAPIC(APIC_TMRDIV, 0x3);
-    writeAPIC(APIC_TMRINITCNT, 0xFFFFFFFF);
-    //asm_pit_sleep_1ms();
-    //writeAPIC(APIC_LVT_TMR, APIC_LVT_INT_MASKED); //??
-    uint32_t ticksInS = 0xFFFFFFFF - readAPIC(APIC_TMRCURRCNT);
-
-    klog("%d MHz bus speed",ticksInS/1000);
-
-    uint32_t countdown=0x0fffffff; // TODO: calc to be constant, depending on bus speed. (use pit for measurement?)
-    writeAPIC(APIC_TMRDIV, 0x3);
-    writeAPIC(APIC_LVT_TMR, 200 | TMR_PERIODIC);
-    writeAPIC(APIC_TMRINITCNT, countdown);
 }
+