20 lines
1.1 KiB
C
20 lines
1.1 KiB
C
#include <stdint.h>
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static inline void outb(uint16_t port, uint8_t val)
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{
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__asm__ volatile ( "outb %b0, %w1" : : "a"(val), "Nd"(port) : "memory");
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/* There's an outb %al, $imm8 encoding, for compile-time constant port numbers that fit in 8b. (N constraint).
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* Wider immediate constants would be truncated at assemble-time (e.g. "i" constraint).
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* The outb %al, %dx encoding is the only option for all other cases.
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* %1 expands to %dx because port is a uint16_t. %w1 could be used if we had the port number a wider C type */
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}
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static inline void inb(uint16_t port, uint8_t val)
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{
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__asm__ volatile ( "inb %b0, %w1" : : "a"(val), "Nd"(port) : "memory");
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/* There's an outb %al, $imm8 encoding, for compile-time constant port numbers that fit in 8b. (N constraint).
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* Wider immediate constants would be truncated at assemble-time (e.g. "i" constraint).
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* The outb %al, %dx encoding is the only option for all other cases.
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* %1 expands to %dx because port is a uint16_t. %w1 could be used if we had the port number a wider C type */
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}
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