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Floating point

When you first try to issue floating point instructions on the processor, you may run into a “Device Not Found” exception. This is because the Pintos starter code intializes the CR0 register to indicate that there is no FPU by setting the CR0_EM bit. You must update this in threads/start.S to remove the flag and indicate to the processor that the FPU is present.

- orl $CR0_PE | CR0_PG | CR0_WP | CR0_EM, %eax
+ orl $CR0_PE | CR0_PG | CR0_WP, %eax

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