(C'est courant comme code en plus :

u-boot (driver/ns16550.c): void NS16550_putc (NS16550_t com_port, char c) { while ((com_port->lsr & LSR_THRE) == 0); com_port->thr = c; }

Linux (arch/powerpc/boot/ns16550.c) : static void ns16550_putc(unsigned char c) { while ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_THRE) == 0); out_8(reg_base, c); }

etc..