From: Joshua Wise Date: Fri, 7 Nov 2008 19:51:42 +0000 (-0500) Subject: Add a small serial driver X-Git-Url: http://git.joshuawise.com/netwatch.git/commitdiff_plain/e931b1fe079024613c42c0c3fac66ac1421829f6?ds=sidebyside;hp=--cc Add a small serial driver --- e931b1fe079024613c42c0c3fac66ac1421829f6 diff --git a/aseg/Makefile b/aseg/Makefile index 0ffd379..76eaa45 100644 --- a/aseg/Makefile +++ b/aseg/Makefile @@ -30,7 +30,8 @@ LWIP_OBJS = \ OBJS=counter.o firstrun.o ../pci/pci-raw.o ../lib/minilib.o ../lib/console.o \ ../ich2/smram-ich2.o ../ich2/smi.o vga-overlay.o packet.o \ ../lib/sprintf.o ../lib/doprnt.o ../pci/pci.o ../net/net.o \ - ../ich2/ich2-timer.o ../pci/pci-bother.o ../net/3c90x.o keyboard.o $(LWIP_OBJS) + ../ich2/ich2-timer.o ../pci/pci-bother.o ../net/3c90x.o keyboard.o \ + ../lib/serial.o $(LWIP_OBJS) all: aseg.elf diff --git a/lib/serial.c b/lib/serial.c new file mode 100644 index 0000000..5318c95 --- /dev/null +++ b/lib/serial.c @@ -0,0 +1,50 @@ +#include +#include + +#define SER_BASE 0x3F8 +#define SER_THR 0x0 +#define SER_RBR 0x0 +#define SER_DLL 0x0 +#define SER_IER 0x1 +#define SER_DLM 0x1 +#define SER_IIR 0x2 +#define SER_FCR 0x2 +#define SER_LCR 0x3 +#define SER_LCR_DLAB 0x80 +#define SER_MCR 0x4 +#define SER_LSR 0x5 +#define SER_LSR_THR_EMPTY 0x20 +#define SER_MSR 0x6 +#define SER_SR 0x7 + +#define SER_BAUD_BASE 115200 +#define SER_BAUD_REQ 115200 + +void _outb(unsigned short port, unsigned char d) +{ + outb(SER_BASE + port, d); +} + +unsigned char _inb(unsigned short port) +{ + return inb(SER_BASE + port); +} + +void serial_init() +{ + unsigned short baud = SER_BAUD_REQ / SER_BAUD_BASE; + _outb(SER_LCR, inb(SER_LCR) | SER_LCR_DLAB); + _outb(SER_DLL, baud & 0xFF); + _outb(SER_DLM, baud >> 8); + _outb(SER_LCR, inb(SER_LCR) & ~SER_LCR_DLAB); + _outb(SER_IER, 0x0); + _outb(SER_FCR, 0x0); /* FIFOs off */ + _outb(SER_LCR, 0x03); /* 8 data bits, one stop bit, no parity */ +} + +void serial_tx(unsigned char c) +{ + while (!(_inb(SER_LSR) & SER_LSR_THR_EMPTY)) + ; + _outb(SER_THR, c); +}