--- /dev/null
+/*
+ * Copyright (C) 2007 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 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.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <ipxe/uaccess.h>
+#include <ipxe/smbios.h>
+
+/** @file
+ *
+ * System Management BIOS
+ *
+ */
+
+/** SMBIOS entry point descriptor */
+static struct smbios smbios = {
+ .address = UNULL,
+};
+
+/**
+ * Scan for SMBIOS entry point structure
+ *
+ * @v start Start address of region to scan
+ * @v len Length of region to scan
+ * @v entry SMBIOS entry point structure to fill in
+ * @ret rc Return status code
+ */
+int find_smbios_entry ( userptr_t start, size_t len,
+ struct smbios_entry *entry ) {
+ uint8_t buf[256]; /* 256 is maximum length possible */
+ static size_t offset = 0; /* Avoid repeated attempts to locate SMBIOS */
+ size_t entry_len;
+ unsigned int i;
+ uint8_t sum;
+
+ /* Try to find SMBIOS */
+ for ( ; offset < len ; offset += 0x10 ) {
+
+ /* Read start of header and verify signature */
+ copy_from_user ( entry, start, offset, sizeof ( *entry ) );
+ if ( entry->signature != SMBIOS_SIGNATURE )
+ continue;
+
+ /* Read whole header and verify checksum */
+ entry_len = entry->len;
+ assert ( entry_len <= sizeof ( buf ) );
+ copy_from_user ( buf, start, offset, entry_len );
+ for ( i = 0, sum = 0 ; i < entry_len ; i++ ) {
+ sum += buf[i];
+ }
+ if ( sum != 0 ) {
+ DBG ( "SMBIOS at %08lx has bad checksum %02x\n",
+ user_to_phys ( start, offset ), sum );
+ continue;
+ }
+
+ /* Fill result structure */
+ DBG ( "Found SMBIOS v%d.%d entry point at %08lx\n",
+ entry->major, entry->minor,
+ user_to_phys ( start, offset ) );
+ return 0;
+ }
+
+ DBG ( "No SMBIOS found\n" );
+ return -ENODEV;
+}
+
+/**
+ * Find SMBIOS strings terminator
+ *
+ * @v offset Offset to start of strings
+ * @ret offset Offset to strings terminator, or 0 if not found
+ */
+static size_t find_strings_terminator ( size_t offset ) {
+ size_t max_offset = ( smbios.len - 2 );
+ uint16_t nulnul;
+
+ for ( ; offset <= max_offset ; offset++ ) {
+ copy_from_user ( &nulnul, smbios.address, offset, 2 );
+ if ( nulnul == 0 )
+ return ( offset + 1 );
+ }
+ return 0;
+}
+
+/**
+ * Find specific structure type within SMBIOS
+ *
+ * @v type Structure type to search for
+ * @v instance Instance of this type of structure
+ * @v structure SMBIOS structure descriptor to fill in
+ * @ret rc Return status code
+ */
+int find_smbios_structure ( unsigned int type, unsigned int instance,
+ struct smbios_structure *structure ) {
+ unsigned int count = 0;
+ size_t offset = 0;
+ size_t strings_offset;
+ size_t terminator_offset;
+ int rc;
+
+ /* Find SMBIOS */
+ if ( ( smbios.address == UNULL ) &&
+ ( ( rc = find_smbios ( &smbios ) ) != 0 ) )
+ return rc;
+ assert ( smbios.address != UNULL );
+
+ /* Scan through list of structures */
+ while ( ( ( offset + sizeof ( structure->header ) ) < smbios.len )
+ && ( count < smbios.count ) ) {
+
+ /* Read next SMBIOS structure header */
+ copy_from_user ( &structure->header, smbios.address, offset,
+ sizeof ( structure->header ) );
+
+ /* Determine start and extent of strings block */
+ strings_offset = ( offset + structure->header.len );
+ if ( strings_offset > smbios.len ) {
+ DBG ( "SMBIOS structure at offset %zx with length "
+ "%x extends beyond SMBIOS\n", offset,
+ structure->header.len );
+ return -ENOENT;
+ }
+ terminator_offset = find_strings_terminator ( strings_offset );
+ if ( ! terminator_offset ) {
+ DBG ( "SMBIOS structure at offset %zx has "
+ "unterminated strings section\n", offset );
+ return -ENOENT;
+ }
+ structure->strings_len = ( terminator_offset - strings_offset);
+
+ DBG ( "SMBIOS structure at offset %zx has type %d, length %x, "
+ "strings length %zx\n", offset, structure->header.type,
+ structure->header.len, structure->strings_len );
+
+ /* If this is the structure we want, return */
+ if ( ( structure->header.type == type ) &&
+ ( instance-- == 0 ) ) {
+ structure->offset = offset;
+ return 0;
+ }
+
+ /* Move to next SMBIOS structure */
+ offset = ( terminator_offset + 1 );
+ count++;
+ }
+
+ DBG ( "SMBIOS structure type %d not found\n", type );
+ return -ENOENT;
+}
+
+/**
+ * Copy SMBIOS structure
+ *
+ * @v structure SMBIOS structure descriptor
+ * @v data Buffer to hold SMBIOS structure
+ * @v len Length of buffer
+ * @ret rc Return status code
+ */
+int read_smbios_structure ( struct smbios_structure *structure,
+ void *data, size_t len ) {
+
+ assert ( smbios.address != UNULL );
+
+ if ( len > structure->header.len )
+ len = structure->header.len;
+ copy_from_user ( data, smbios.address, structure->offset, len );
+ return 0;
+}
+
+/**
+ * Find indexed string within SMBIOS structure
+ *
+ * @v structure SMBIOS structure descriptor
+ * @v index String index
+ * @v data Buffer for string
+ * @v len Length of string buffer
+ * @ret rc Length of string, or negative error
+ */
+int read_smbios_string ( struct smbios_structure *structure,
+ unsigned int index, void *data, size_t len ) {
+ size_t strings_start = ( structure->offset + structure->header.len );
+ size_t strings_end = ( strings_start + structure->strings_len );
+ size_t offset;
+ size_t string_len;
+
+ assert ( smbios.address != UNULL );
+
+ /* String numbers start at 1 (0 is used to indicate "no string") */
+ if ( ! index )
+ return -ENOENT;
+
+ for ( offset = strings_start ; offset < strings_end ;
+ offset += ( string_len + 1 ) ) {
+ /* Get string length. This is known safe, since the
+ * smbios_strings struct is constructed so as to
+ * always end on a string boundary.
+ */
+ string_len = strlen_user ( smbios.address, offset );
+ if ( --index == 0 ) {
+ /* Copy string, truncating as necessary. */
+ if ( len > string_len )
+ len = string_len;
+ copy_from_user ( data, smbios.address, offset, len );
+ return string_len;
+ }
+ }
+
+ DBG ( "SMBIOS string index %d not found\n", index );
+ return -ENOENT;
+}
+
+/**
+ * Get SMBIOS version
+ *
+ * @ret version Version, or negative error
+ */
+int smbios_version ( void ) {
+ int rc;
+
+ /* Find SMBIOS */
+ if ( ( smbios.address == UNULL ) &&
+ ( ( rc = find_smbios ( &smbios ) ) != 0 ) )
+ return rc;
+ assert ( smbios.address != UNULL );
+
+ return smbios.version;
+}
Code Review / kvmfornfv.git / blobdiff