aboutsummaryrefslogtreecommitdiff
path: root/core.c
diff options
context:
space:
mode:
Diffstat (limited to 'core.c')
-rw-r--r--core.c211
1 files changed, 211 insertions, 0 deletions
diff --git a/core.c b/core.c
new file mode 100644
index 0000000..8746ec4
--- /dev/null
+++ b/core.c
@@ -0,0 +1,211 @@
+/*
+ * 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 "verilog_constants.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[] = {
+ { "trng", 4 * CORE_SIZE }, /* Four empty slots after trng */
+ { "rosc ent", 3 * CORE_SIZE }, /* Three empty slots after rosc */
+ { "csprng", 4 * CORE_SIZE }, /* Four 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:
+ */