X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/8f6c56a50524aa785f7e596d52dddfb331e18961..c18c124eaa464aaaa5549e99e5a70fc9cbb50944:/pexpert/i386/pe_serial.c diff --git a/pexpert/i386/pe_serial.c b/pexpert/i386/pe_serial.c index ff104bba5..f056487a0 100644 --- a/pexpert/i386/pe_serial.c +++ b/pexpert/i386/pe_serial.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * @@ -34,10 +34,6 @@ #include #include -void serial_putc(char); -int serial_getc(void); -int serial_init(void); - /* standard port addresses */ enum { COM1_PORT_ADDR = 0x3f8, @@ -56,7 +52,8 @@ enum { UART_LCR = 3, /* line control register */ UART_MCR = 4, /* modem control register */ UART_LSR = 5, /* line status register */ - UART_MSR = 6 /* modem status register */ + UART_MSR = 6, /* modem status register */ + UART_SCR = 7 /* scratch register */ }; enum { @@ -73,12 +70,18 @@ enum { }; enum { + UART_LSR_DR = 0x01, + UART_LSR_OE = 0x02, + UART_LSR_PE = 0x04, + UART_LSR_FE = 0x08, UART_LSR_THRE = 0x20 }; -#define UART_BAUD_RATE 115200 +static unsigned uart_baud_rate = 115200; #define UART_PORT_ADDR COM1_PORT_ADDR +#define UART_CLOCK 1843200 /* 1.8432 MHz clock */ + #define WRITE(r, v) outb(UART_PORT_ADDR + UART_##r, v) #define READ(r) inb(UART_PORT_ADDR + UART_##r) #define DELAY(x) { volatile int _d_; for (_d_ = 0; _d_ < (10000*x); _d_++) ; } @@ -88,22 +91,18 @@ static int uart_initted = 0; /* 1 if init'ed */ static int uart_probe( void ) { - /* Verify that the Divisor Register is accessible */ - - WRITE( LCR, UART_LCR_DLAB ); - WRITE( DLL, 0x5a ); - if (READ(DLL) != 0x5a) return 0; - WRITE( DLL, 0xa5 ); - if (READ(DLL) != 0xa5) return 0; - WRITE( LCR, 0x00 ); + /* Verify that the Scratch Register is accessible */ + + WRITE( SCR, 0x5a ); + if (READ(SCR) != 0x5a) return 0; + WRITE( SCR, 0xa5 ); + if (READ(SCR) != 0xa5) return 0; return 1; } static void uart_set_baud_rate( unsigned long baud_rate ) { - #define UART_CLOCK 1843200 /* 1.8432 MHz clock */ - const unsigned char lcr = READ( LCR ); unsigned long div; @@ -126,9 +125,41 @@ uart_putc( char c ) WRITE( THR, c ); } +static int +uart_getc( void ) +{ + /* + * This function returns: + * -1 : no data + * -2 : receiver error + * >0 : character received + */ + + unsigned char lsr; + + if (!uart_initted) return -1; + + lsr = READ( LSR ); + + if ( lsr & (UART_LSR_FE | UART_LSR_PE | UART_LSR_OE) ) + { + READ( RBR ); /* discard */ + return -2; + } + + if ( lsr & UART_LSR_DR ) + { + return READ( RBR ); + } + + return -1; +} + int serial_init( void ) { - if ( /*uart_initted ||*/ uart_probe() == 0 ) return 0; + unsigned serial_baud_rate = 0; + + if ( uart_probe() == 0 ) return 0; /* Disable hardware interrupts */ @@ -143,9 +174,16 @@ int serial_init( void ) WRITE( LCR, UART_LCR_8BITS ); - /* Set baud rate */ + /* Set baud rate - use the supplied boot-arg if available */ - uart_set_baud_rate( UART_BAUD_RATE ); + if (PE_parse_boot_argn("serialbaud", &serial_baud_rate, sizeof (serial_baud_rate))) + { + /* Valid divisor? */ + if (!((UART_CLOCK / 16) % serial_baud_rate)) { + uart_baud_rate = serial_baud_rate; + } + } + uart_set_baud_rate( uart_baud_rate ); /* Assert DTR# and RTS# lines (OUT2?) */ @@ -163,10 +201,9 @@ int serial_init( void ) void serial_putc( char c ) { uart_putc(c); - if (c == '\n') uart_putc('\r'); } int serial_getc( void ) { - return 0; /* not supported */ + return uart_getc(); }