52 lines
1.1 KiB
C++
52 lines
1.1 KiB
C++
#include "idt.h"
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extern int _mt_begin;
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extern int _mt_idt;
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using namespace Genode;
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class Descriptor
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{
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private:
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uint16_t _limit;
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uint64_t _base;
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public:
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Descriptor(uint16_t l, uint64_t b) : _limit(l), _base (b) {};
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} __attribute__((packed));
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addr_t Idt::_virt_idt_addr(addr_t const virt_base)
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{
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addr_t const phys = (addr_t)&_mt_idt;
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addr_t const phys_base = (addr_t)&_mt_begin;
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return virt_base + (phys - phys_base);
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}
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void Idt::setup()
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{
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/* TODO: Calculate from _mt_isrs label */
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uint64_t base = 0;
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for (unsigned vec = 0; vec < SIZE_IDT; vec++) {
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/* ISRs are padded to 4 bytes */
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base = vec * 0xc;
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_table[vec].offset_15_00 = base & 0xffff;
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_table[vec].segment_sel = 8;
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_table[vec].flags = 0x8e00;
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_table[vec].offset_31_16 = (base >> 16) & 0xffff;
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_table[vec].offset_63_32 = (base >> 32) & 0xffff;
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}
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/* Set DPL of syscall entry to 3 */
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_table[SYSCALL_VEC].flags = _table[SYSCALL_VEC].flags | 0x6000;
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}
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void Idt::load(addr_t const virt_base)
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{
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asm volatile ("lidt %0" : : "m" (Descriptor (sizeof(_table) - 1,
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reinterpret_cast<uint64_t>(_table))));
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}
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