147 lines
3.1 KiB
C
147 lines
3.1 KiB
C
//Functions.c
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//05/07/03 Josh Holtrop
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//for HOS
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//Modified: 10/30/03
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//Writes a byte out to a port
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inline void outportb(unsigned int port, unsigned char value) // Output a byte to a port
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{
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asm volatile ("outb %%al,%%dx"::"d" (port), "a" (value));
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};
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//Writes a word out to a port
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inline void outportw(unsigned int port, unsigned int value) // Output a word to a port
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{
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asm volatile ("outw %%ax,%%dx"::"d" (port), "a" (value));
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};
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//Reads a byte from a port
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inline byte inportb(unsigned short port)
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{
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unsigned char ret_val;
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asm volatile("inb %w1,%b0"
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: "=a"(ret_val)
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: "d"(port));
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return ret_val;
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};
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//Enables (SeTs) Interrupt Flag on the processor
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inline void enable_ints()
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{
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asm("sti");
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};
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//Disables (CLears) Interrupt Flag on the processor
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inline void disable_ints()
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{
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asm("cli");
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};
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//Re-maps the Programmable Interrupr Controllers so IRQ0->pic1 base address, IRG8->pic2 base address
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void remap_pics(int pic1, int pic2)
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{
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byte a1, a2;
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a1 = inportb(PIC1_DATA); //0x21
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a2 = inportb(PIC2_DATA); //0xA1
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outportb(PIC1_COMMAND, ICW1_INIT+ICW1_ICW4); //0x20, 0x10+0x01 00010001b
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outportb(PIC2_COMMAND, ICW1_INIT+ICW1_ICW4); //0xA0, 0x10+0x01 00010001b
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outportb(PIC1_DATA, pic1); //0x21, pic1
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outportb(PIC2_DATA, pic2); //0xA1, pic2
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outportb(PIC1_DATA, 4); //0x21, 0x04 00000100b
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outportb(PIC2_DATA, 2); //0xA1, 0x02 00000010b
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outportb(PIC1_DATA, ICW4_8086); //0x21, 0x01 00000001b
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outportb(PIC2_DATA, ICW4_8086); //0xA1, 0x01 00000001b
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outportb(PIC1_DATA, a1); //0x21
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outportb(PIC2_DATA, a2); //0xA1
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}
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//Masks interrupts on first Programmable Interrupt Controller
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inline void pic1_mask(byte mask)
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{
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outportb(PIC1_DATA, mask); //0x21, maskfield *OCW1*
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}
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//Masks interrupts on second Programmable Interrupt Controller
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inline void pic2_mask(byte mask)
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{
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outportb(PIC2_DATA, mask); //0xA1, maskfield *OCW1*
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}
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//Restarts the computer
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inline void restart()
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{
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byte temp;
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do
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{
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temp = inportb(0x64);
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if (temp & 1)
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inportb(0x60);
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} while(temp & 2);
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outportb (0x64, 0xfe);
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for (;;)
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{
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}
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}
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//Halts (freezes) the computer
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inline void halt()
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{
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asm("cli");
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asm("hlt");
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while (1)
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;
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}
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//Initializes 8253 Programmable Interrupt Timer
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inline void init_timer()
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{
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//set timer : 2e9c = 100hz
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outportb(0x43, 0x34);
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outportb(0x40, 0x9c); //lsb
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outportb(0x40, 0x2e); //msb
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}
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//Invalidates the page tables to re-cache the Translation Lookaside Buffer
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/*inline void invlpg()
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{
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asm("invlpg");
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}*/
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//Signals an End Of Interrupt signal to the first PIC
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inline void eoi()
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{
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outportb(0x20, 0x20);
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}
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//Signals an End Of Interrupt signal to both the second and first PIC unit
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inline void eoi2()
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{
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outportb(0xA0, 0x20);
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outportb(0x20, 0x20);
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}
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//Returns the size of the kernel (code & data)
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// - this does not include the bss section
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// - this should be 4kb aligned per the linker script
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// - this should be the size of kernel.bin
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inline dword kernel_size()
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{
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return (dword)(&_bss)-(dword)(&_code);
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}
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