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https://github.com/Fennix-Project/Kernel.git
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86 lines
2.2 KiB
C++
86 lines
2.2 KiB
C++
#include <syscalls.hpp>
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#include <cpu.hpp>
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#include "cpu/gdt.hpp"
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// https://supercip971.github.io/02-wingos-syscalls.html
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using namespace CPU::x64;
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// "Core/SystemCalls.cpp"
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extern "C" uint64_t SystemCallsHandler(SyscallsFrame *regs);
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extern "C" void SystemCallHandlerStub();
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extern "C" __attribute__((naked, used, no_stack_protector)) void SystemCallHandlerStub_broken()
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{
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// asmv(
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// // "cmp $0x08, 0x8(%rsp)\n"
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// // "je 1f\n"
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// "swapgs\n"
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// // "1:\n"
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// "mov %rsp, 0x8(%gs)\n" // CPUData->TempStack
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// "mov 0x0(%gs), %rsp\n" // CPUData->SystemCallStack
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// "push $0x1b\n" // user data segment
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// "push 0x8(%gs)\n" // saved stack
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// "push %r11\n" // saved rflags
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// "push $0x23\n" // user code segment
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// "push %rcx\n" // Current RIP
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// "push %rax\n"
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// "push %rbx\n"
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// "push %rcx\n"
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// "push %rdx\n"
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// "push %rsi\n"
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// "push %rdi\n"
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// "push %rbp\n"
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// "push %r8\n"
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// "push %r9\n"
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// "push %r10\n"
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// "push %r11\n"
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// "push %r12\n"
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// "push %r13\n"
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// "push %r14\n"
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// "push %r15\n"
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// "mov %rsp, %rdi\n"
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// "mov $0, %rbp\n"
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// "call SystemCallsHandler\n"
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// "pop %r15\n"
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// "pop %r14\n"
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// "pop %r13\n"
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// "pop %r12\n"
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// "pop %r11\n"
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// "pop %r10\n"
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// "pop %r9\n"
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// "pop %r8\n"
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// "pop %rbp\n"
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// "pop %rdi\n"
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// "pop %rsi\n"
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// "pop %rdx\n"
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// "pop %rcx\n"
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// "pop %rbx\n"
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// /* "pop %rax\n" */
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// "mov 0x8(%gs), %rsp\n" // CPUData->TempStack
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// // "cmp $0x08, 0x8(%rsp)\n"
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// // "je 1f\n"
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// "swapgs\n"
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// // "1:\n"
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// "sti\n"
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// "sysretq\n");
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}
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void InitializeSystemCalls()
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{
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wrmsr(MSR_EFER, rdmsr(MSR_EFER) | 1);
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wrmsr(MSR_STAR, ((uint64_t)(GDT_KERNEL_CODE) << 32) | ((uint64_t)(GDT_KERNEL_DATA | 3) << 48));
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wrmsr(MSR_LSTAR, (uint64_t)SystemCallHandlerStub);
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wrmsr(MSR_SYSCALL_MASK, (uint64_t)(1 << 9));
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}
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