ref: d540dcf6834b4bec8a2d21f2fe95eccf49f97b03
dir: /os/boot/puma/outb.c/
typedef unsigned short ushort; typedef unsigned char uchar; enum { IsaIOBase = 0xf0000000, IsaMemBase = 0xe0000000, IOBase = 0x300, MemBase = 0xc0000, TxFrame = 0x0a00, }; #define regw(reg, val) *((ushort *)IsaMemBase + MemBase + (reg)) = (val) void main(void) { regw(TxFrame, 0x1234); }