/*
* core.c
* ------
* This module contains code to probe the FPGA for its installed cores.
*
* Author: Paul Selkirk, Rob Austein
* Copyright (c) 2015, NORDUnet A/S All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of the NORDUnet nor the names of its contributors may
* be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include "hal.h"
#include "hal_internal.h"
/*
* Each Cryptech core has a set of 4-byte registers, which are accessed
* through a 16-bit address. The address space is divided as follows:
* 3 bits segment selector | up to 8 segments
* 5 bits core selector | up to 32 cores/segment (see note below)
* 8 bits register selector | up to 256 registers/core (see modexp below)
*
* i.e, the address is structured as:
* sss ccccc rrrrrrrr
*
* The I2C and UART communication channels use this 16-bit address format
* directly in their read and write commands.
*
* The EIM communications channel translates this 16-bit address into a
* 32-bit memory-mapped address in the range 0x08000000..807FFFF:
* 00001000000000 sss 0 ccccc rrrrrrrr 00
*
* EIM, as implemented on the Novena, uses a 19-bit address space:
* Bits 18..16 are the semgent selector.
* Bits 15..10 are the core selector.
* Bits 9..2 are the register selector.
* Bits 1..0 are zero, because reads and writes are always word aligned.
*
* Note that EIM can support 64 cores per segment, but we sacrifice one bit
* in order to map it into a 16-bit address space.
*/
/*
* Structure of our internal database is private, in case we want to
* be change representation (array, tree, list of lists, whatever) at
* some later date without having to change the public API.
*/
struct hal_core {
hal_core_info_t info;
struct hal_core *next;
};
/*
* Check whether a core's name matches a particular string. This is a
* bit nasty due to non-null-terminated fixed-length names.
*/
static int name_matches(const hal_core_t *const core, const char * const name)
{
return (core != NULL && name != NULL && *name != '\0' &&
strncmp(name, core->info.name, strnlen(name, sizeof(core->info.name))) == 0);
}
/*
* Probe the FPGA and build our internal database.
*
* At the moment this knows far more than it should about pecularities
* of certain cores. In theory at least some of this will be fixed
* soon on the Verilog side. Adding a core-length word to the core
* header sure would make this simpler.
*/
#define CORE_MIN 0
#define CORE_MAX 0x10000
#define CORE_SIZE 0x100
/* Extra space to leave after particular cores. Yummy. */
static const struct { const char *name; hal_addr_t extra; } gaps[] = {
{ "csprng", 11 * CORE_SIZE }, /* empty slots after csprng */
{ "modexps6", 3 * CORE_SIZE }, /* ModexpS6 uses four slots */
};
static hal_core_t *probe_cores(void)
{
static hal_core_t *head = NULL;
if (head != NULL)
return head;
hal_core_t **tail = &head;
hal_core_t *core = NULL;
hal_error_t err = HAL_OK;
for (hal_addr_t addr = CORE_MIN; addr < CORE_MAX; addr += CORE_SIZE) {
if (core == NULL && (core = malloc(sizeof(hal_core_t))) == NULL) {
err = HAL_ERROR_ALLOCATION_FAILURE;
goto fail;
}
memset(core, 0, sizeof(*core));
core->info.base = addr;
if ((err = hal_io_read(core, ADDR_NAME0, (uint8_t *) core->info.name, 8)) != HAL_OK ||
(err = hal_io_read(core, ADDR_VERSION, (uint8_t *) core->info.version, 4)) != HAL_OK)
goto fail;
if (core->info.name[0] == '\0')
continue;
for (int i = 0; i < sizeof(gaps)/sizeof(*gaps); i++) {
if (name_matches(core, gaps[i].name)) {
addr += gaps[i].extra;
break;
}
}
*tail = core;
tail = &core->next;
core = NULL;
}
if (core != NULL)
free(core);
return head;
fail:
if (core != NULL)
free(core);
while ((core = head) != NULL) {
head = core->next;
free(core);
}
return NULL;
}
const hal_core_t * hal_core_iterate(const hal_core_t *core)
{
return core == NULL ? probe_cores() : core->next;
}
const hal_core_t *hal_core_find(const char *name, const hal_core_t *core)
{
for (core = hal_core_iterate(core); core != NULL; core = core->next)
if (name_matches(core, name))
return core;
return NULL;
}
hal_error_t hal_core_check_name(const hal_core_t **core, const char *name)
{
if (core == NULL || name == NULL)
return HAL_ERROR_BAD_ARGUMENTS;
if (*core == NULL && (*core = hal_core_find(name, NULL)) != NULL)
return HAL_OK;
if (*core == NULL || !name_matches(*core, name))
return HAL_ERROR_CORE_NOT_FOUND;
return HAL_OK;
}
hal_addr_t hal_core_base(const hal_core_t *core)
{
return core == NULL ? 0 : core->info.base;
}
const hal_core_info_t *hal_core_info(const hal_core_t *core)
{
return core == NULL ? NULL : &core->info;
}
/*
* Local variables:
* indent-tabs-mode: nil
* End:
*/
