/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright 2021 OmniOS Community Edition (OmniOSce) Association.
 * Copyright 2025 Oxide Computer Company
 */

#include <sys/types.h>
#include <sys/ucode.h>
#include <sys/ucode_amd.h>
#include <sys/stdbool.h>
#ifdef  _KERNEL
#include <sys/systm.h>
#else
#include <strings.h>
#endif

/*
 * Perform basic validation of an AMD microcode container file.
 */
ucode_errno_t
ucode_validate_amd(uint8_t *ucodep, size_t size)
{
        uint8_t *ptr = ucodep;
        bool first = true;
        uint32_t magic;

        if (ucodep == NULL || size <= 0)
                return (EM_INVALIDARG);

        /* Magic Number */
        bcopy(ptr, &magic, sizeof (magic));
        if (magic != UCODE_AMD_CONTAINER_MAGIC)
                return (EM_FILEFORMAT);
        ptr += sizeof (magic);
        size -= sizeof (magic);

        /*
         * There follow one or more TLV-encoded sections. We expect that the
         * first section is an equivalence table and all subsequent sections
         * are patches and return EM_FILEFORMAT if that is not the case.
         */
        while (size > sizeof (ucode_section_amd_t)) {
                ucode_section_amd_t section;

                bcopy(ptr, &section, sizeof (section));
                if (section.usa_size == 0 || section.usa_size > size)
                        return (EM_FILEFORMAT);
                ptr += sizeof (section);
                size -= sizeof (section);

                switch (section.usa_type) {
                case UCODE_AMD_CONTAINER_TYPE_EQUIV:
                        if (!first)
                                return (EM_FILEFORMAT);
                        /*
                         * The equivalence table maps processor IDs (family,
                         * stepping, model) to a Microcode Patch Equivalent
                         * Processor ID. We just verify that it its size is a
                         * whole number of entries.
                         */
                        if (section.usa_size % sizeof (ucode_eqtbl_amd_t) != 0)
                                return (EM_FILEFORMAT);
                        break;

                case UCODE_AMD_CONTAINER_TYPE_PATCH:
                        if (first)
                                return (EM_FILEFORMAT);
                        break;

                default:
                        return (EM_FILEFORMAT);
                }

                size -= section.usa_size;
                ptr += section.usa_size;
                first = false;
        }

        /* We don't expect there to be any unaccounted for trailing data */
        if (size != 0)
                return (EM_FILEFORMAT);

        return (EM_OK);
}