/*
* Copyright (C) 2015 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <ipxe/console.h>
#include <ipxe/init.h>
#include <realmode.h>
#include <int13.h>
#include <config/console.h>
/** @file
*
* INT13 disk log console
*
*/
/* Set default console usage if applicable */
#if ! ( defined ( CONSOLE_INT13 ) && CONSOLE_EXPLICIT ( CONSOLE_INT13 ) )
#undef CONSOLE_INT13
#define CONSOLE_INT13 ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_LOG )
#endif
/** Disk drive number */
#define INT13CON_DRIVE 0x80
/** Log partition type */
#define INT13CON_PARTITION_TYPE 0xe0
/** Maximum number of outstanding unwritten characters */
#define INT13CON_MAX_UNWRITTEN 64
/** Log partition header */
struct int13con_header {
/** Magic signature */
char magic[10];
} __attribute__ (( packed ));
/** Log partition magic signature */
#define INT13CON_MAGIC "iPXE LOG\n\n"
/** Original INT13 vector */
static struct segoff __bss16 ( int13con_vector );
#define int13con_vector __use_data16 ( int13con_vector )
/** Sector buffer */
static uint8_t __bss16_array ( int13con_buffer, [INT13_BLKSIZE] );
#define int13con_buffer __use_data16 ( int13con_buffer )
/** Disk address packet */
static struct int13_disk_address __bss16 ( int13con_address );
#define int13con_address __use_data16 ( int13con_address )
/** Current LBA */
static uint64_t int13con_lba;
/** Maximum LBA */
static uint64_t int13con_max_lba;
/** Current offset within sector */
static size_t int13con_offset;
/** Number of unwritten characters */
static size_t int13con_unwritten;
struct console_driver int13con __console_driver;
/**
* Read/write disk sector
*
* @v op Operation
* @v lba Logical block address
* @ret rc Return status code
*/
static int int13con_rw ( unsigned int op, uint64_t lba ) {
uint8_t error;
/* Construct disk address packet */
int13con_address.bufsize = sizeof ( int13con_address );
int13con_address.count = 1;
int13con_address.buffer.segment = rm_ds;
int13con_address.buffer.offset = __from_data16 ( int13con_buffer );
int13con_address.lba = lba;
/* Emulate INT13 via original vector. We do this since iPXE
* (or another subsequent bootloader) may hook INT13 and remap
* drive numbers.
*/
__asm__ ( REAL_CODE ( "pushfw\n\t"
"cli\n\t"
"lcall *int13con_vector\n\t" )
: "=a" ( error )
: "0" ( op << 8 ), "d" ( INT13CON_DRIVE ),
"S" ( __from_data16 ( &int13con_address ) ) );
if ( error ) {
DBG ( "INT13CON operation %04x failed: %02x\n",
op, error );
return -EIO;
}
return 0;
}
/**
* Write character to console
*
* @v character Character
*/
static void int13con_putchar ( int character ) {
static int busy;
int rc;
/* Ignore if we are already mid-logging */
if ( busy )
return;
busy = 1;
/* Write character to buffer */
int13con_buffer[int13con_offset++] = character;
int13con_unwritten++;
/* Write sector to disk, if applicable */
if ( ( int13con_offset == INT13_BLKSIZE ) ||
( int13con_unwritten == INT13CON_MAX_UNWRITTEN ) ||
( character == '\n' ) ) {
/* Write sector to disk */
if ( ( rc = int13con_rw ( INT13_EXTENDED_WRITE,
int13con_lba ) ) != 0 ) {
DBG ( "INT13CON could not write log\n" );
/* Ignore and continue; there's nothing we can do */
}
/* Reset count of unwritten characters */
int13con_unwritten = 0;
}
/* Move to next sector, if applicable */
if ( int13con_offset == INT13_BLKSIZE ) {
/* Disable console if we have run out of space */
if ( int13con_lba >= int13con_max_lba )
int13con.disabled = 1;
/* Clear log buffer */
memset ( int13con_buffer, 0, sizeof ( int13con_buffer ) );
int13con_offset = 0;
/* Move to next sector */
int13con_lba++;
}
/* Clear busy flag */
busy = 0;
}
/**
* Find log partition
*
* @ret rc Return status code
*/
static int int13con_find ( void ) {
struct master_boot_record *mbr =
( ( struct master_boot_record * ) int13con_buffer );
struct int13con_header *hdr =
( ( struct int13con_header * ) int13con_buffer );
struct partition_table_entry part[4];
unsigned int i;
int rc;
/* Read MBR */
if ( ( rc = int13con_rw ( INT13_EXTENDED_READ, 0 ) ) != 0 ) {
DBG ( "INT13CON could not read MBR: %s\n", strerror ( rc ) );
return rc;
}
/* Check MBR magic */
if ( mbr->magic != INT13_MBR_MAGIC ) {
DBG ( "INT13CON incorrect MBR magic\n" );
DBG2_HDA ( 0, mbr, sizeof ( *mbr ) );
return -EINVAL;
}
/* Look for magic partition */
memcpy ( part, mbr->partitions, sizeof ( part ) );
for ( i = 0 ; i < ( sizeof ( part ) / sizeof ( part[0] ) ) ; i++ ) {
/* Skip partitions of the wrong type */
if ( part[i].type != INT13CON_PARTITION_TYPE )
continue;
/* Read partition header */
if ( ( rc = int13con_rw ( INT13_EXTENDED_READ,
part[i].start ) ) != 0 ) {
DBG ( "INT13CON partition %d could not read header: "
"%s\n", ( i + 1 ), strerror ( rc ) );
continue;
}
/* Check partition header */
if ( memcmp ( hdr->magic, INT13CON_MAGIC,
sizeof ( hdr->magic ) ) != 0 ) {
DBG ( "INT13CON partition %d bad magic\n", ( i + 1 ) );
DBG2_HDA ( 0, hdr, sizeof ( *hdr ) );
continue;
}
/* Found log partition */
DBG ( "INT13CON partition %d at [%08x,%08x)\n", ( i + 1 ),
part[i].start, ( part[i].start + part[i].length ) );
int13con_lba = part[i].start;
int13con_max_lba = ( part[i].start + part[i].length - 1 );
/* Initialise log buffer */
memset ( &int13con_buffer[ sizeof ( *hdr ) ], 0,
( sizeof ( int13con_buffer ) - sizeof ( *hdr ) ) );
int13con_offset = sizeof ( hdr->magic );
return 0;
}
DBG ( "INT13CON found no log partition\n" );
return -ENOENT;
}
/**
* Initialise INT13 console
*
*/
static void int13con_init ( void ) {
uint8_t error;
uint16_t check;
unsigned int discard_c;
unsigned int discard_d;
int rc;
/* Check for INT13 extensions */
__asm__ __volatile__ ( REAL_CODE ( "int $0x13\n\t"
"setc %%al\n\t" )
: "=a" ( error ), "=b" ( check ),
"=c" ( discard_c ), "=d" ( discard_d )
: "0" ( INT13_EXTENSION_CHECK << 8 ),
"1" ( 0x55aa ), "3" ( INT13CON_DRIVE ) );
if ( error || ( check != 0xaa55 ) ) {
DBG ( "INT13CON missing extensions (%02x,%04x)\n",
error, check );
return;
}
/* Store original INT13 vector */
copy_from_real ( &int13con_vector, 0, ( 0x13 * 4 ),
sizeof ( int13con_vector ) );
DBG ( "INT13CON using original INT13 vector %04x:%04x\n",
int13con_vector.segment, int13con_vector.offset );
/* Locate log partition */
if ( ( rc = int13con_find() ) != 0)
return;
/* Enable console */
int13con.disabled = 0;
}
/**
* INT13 console initialisation function
*/
struct init_fn int13con_init_fn __init_fn ( INIT_CONSOLE ) = {
.initialise = int13con_init,
};
/** INT13 console driver */
struct console_driver int13con __console_driver = {
.putchar = int13con_putchar,
.disabled = CONSOLE_DISABLED,
.usage = CONSOLE_INT13,
};
