51 lines
1.8 KiB
Python
51 lines
1.8 KiB
Python
import cpu
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import t, c
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# FPU上下文结构体
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@c.Attribute(t.attr.aligned(16))
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class fpu_context:
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data: t.CUInt8T[512] # FXSAVE区域大小
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@t.Object
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class _FPUObject:
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CPUObject: cpu._CPUObject | t.CPtr
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# 初始化FPU
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def __init__(self, CPUObject: cpu._CPUObject | t.CPtr):
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self.enable()
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self.CPUObject = CPUObject
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c.Asm("fninit", [t.ASM_DESCR.CLOBBER_MEMORY])
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# 启用FPU
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def enable(self):
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cr0: t.CUInt64T = self.CPUObject.readCR0()
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# 清除EM位（禁用仿真），设置MP位（监控协处理器）
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cr0 &= ~(1 << 2); # 清除EM位
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cr0 |= (1 << 1); # 设置MP位
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# 写入CR0寄存器
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self.CPUObject.writeCR0(cr0)
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# 读取CR4寄存器
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cr4: t.CUInt64T = self.CPUObject.readCR4()
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# 设置OSFXSR位和OSXMMEXCPT位，启用SSE
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cr4 |= (1 << 9) | (1 << 10)
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# 写入CR4寄存器
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self.CPUObject.writeCR4(cr4)
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# 初始化FPU
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c.Asm("fninit", [t.ASM_DESCR.CLOBBER_MEMORY])
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# 禁用FPU
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def disable(self):
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cr0: t.CUInt64T = self.CPUObject.readCR0()
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# 设置EM位（启用仿真），清除MP位（禁用监控协处理器）
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cr0 |= (1 << 2) # 设置EM位
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cr0 &= ~(1 << 1) # 清除MP位
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# 写入CR0寄存器
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self.CPUObject.writeCR0(cr0)
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# 保存FPU上下文
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def save_context(self, context: fpu_context | t.CPtr):
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# 保存FPU状态到内存
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c.Asm(f"fxsave [{c.AsmInp(context, t.ASM_DESCR.REG_ANY)}]", [t.ASM_DESCR.CLOBBER_MEMORY])
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# 恢复FPU上下文
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def restore_context(self, context: t.CConst | fpu_context | t.CPtr):
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# 从内存恢复FPU状态
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c.Asm(f"fxrstor [{c.AsmInp(context, t.ASM_DESCR.REG_ANY)}]", [t.ASM_DESCR.CLOBBER_MEMORY])
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