esp32: move hw random

components/esp32/CMakeLists.txt

@@ -18,7 +18,6 @@ else()
         "crosscore_int.c"
         "dport_access.c"
         "esp_himem.c"
-        "hw_random.c"
         "spiram.c"
         "spiram_psram.c"
         "system_api_esp32.c")

components/esp32/hw_random.c

@@ -1,69 +0,0 @@
-// Copyright 2016 Espressif Systems (Shanghai) PTE LTD
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-
-#include <stdint.h>
-#include <stddef.h>
-#include <string.h>
-#include <sys/param.h>
-#include "esp_attr.h"
-#include "hal/cpu_hal.h"
-#include "esp32/clk.h"
-#include "soc/wdev_reg.h"
-
-uint32_t IRAM_ATTR esp_random(void)
-{
-    /* The PRNG which implements WDEV_RANDOM register gets 2 bits
-     * of extra entropy from a hardware randomness source every APB clock cycle
-     * (provided WiFi or BT are enabled). To make sure entropy is not drained
-     * faster than it is added, this function needs to wait for at least 16 APB
-     * clock cycles after reading previous word. This implementation may actually
-     * wait a bit longer due to extra time spent in arithmetic and branch statements.
-     *
-     * As a (probably unncessary) precaution to avoid returning the
-     * RNG state as-is, the result is XORed with additional
-     * WDEV_RND_REG reads while waiting.
-     */
-
-    /* This code does not run in a critical section, so CPU frequency switch may
-     * happens while this code runs (this will not happen in the current
-     * implementation, but possible in the future). However if that happens,
-     * the number of cycles spent on frequency switching will certainly be more
-     * than the number of cycles we need to wait here.
-     */
-    uint32_t cpu_to_apb_freq_ratio = esp_clk_cpu_freq() / esp_clk_apb_freq();
-
-    static uint32_t last_ccount = 0;
-    uint32_t ccount;
-    uint32_t result = 0;
-    do {
-        ccount = cpu_hal_get_cycle_count();
-        result ^= REG_READ(WDEV_RND_REG);
-    } while (ccount - last_ccount < cpu_to_apb_freq_ratio * 16);
-    last_ccount = ccount;
-    return result ^ REG_READ(WDEV_RND_REG);
-}
-
-void esp_fill_random(void *buf, size_t len)
-{
-    assert(buf != NULL);
-    uint8_t *buf_bytes = (uint8_t *)buf;
-    while (len > 0) {
-        uint32_t word = esp_random();
-        uint32_t to_copy = MIN(sizeof(word), len);
-        memcpy(buf_bytes, &word, to_copy);
-        buf_bytes += to_copy;
-        len -= to_copy;
-    }
-}

components/esp32c3/CMakeLists.txt

@@ -18,7 +18,6 @@ else()
              "esp_hmac.c"
              "esp_ds.c"
              "esp_crypto_lock.c"
-             "hw_random.c"
              "memprot.c"
              "system_api_esp32c3.c")
     set(include_dirs "include")

components/esp32c3/hw_random.c

@@ -1,68 +0,0 @@
-// Copyright 2020 Espressif Systems (Shanghai) PTE LTD
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include <stdint.h>
-#include <stddef.h>
-#include <string.h>
-#include <sys/param.h>
-#include "esp_attr.h"
-#include "esp32c3/clk.h"
-#include "soc/wdev_reg.h"
-#include "hal/cpu_hal.h"
-
-uint32_t IRAM_ATTR esp_random(void)
-{
-    /* The PRNG which implements WDEV_RANDOM register gets 2 bits
-     * of extra entropy from a hardware randomness source every APB clock cycle
-     * (provided WiFi or BT are enabled). To make sure entropy is not drained
-     * faster than it is added, this function needs to wait for at least 16 APB
-     * clock cycles after reading previous word. This implementation may actually
-     * wait a bit longer due to extra time spent in arithmetic and branch statements.
-     *
-     * As a (probably unncessary) precaution to avoid returning the
-     * RNG state as-is, the result is XORed with additional
-     * WDEV_RND_REG reads while waiting.
-     */
-
-    /* This code does not run in a critical section, so CPU frequency switch may
-     * happens while this code runs (this will not happen in the current
-     * implementation, but possible in the future). However if that happens,
-     * the number of cycles spent on frequency switching will certainly be more
-     * than the number of cycles we need to wait here.
-     */
-    uint32_t cpu_to_apb_freq_ratio = esp_clk_cpu_freq() / esp_clk_apb_freq();
-
-    static uint32_t last_ccount = 0;
-    uint32_t ccount;
-    uint32_t result = 0;
-    do {
-        ccount = cpu_hal_get_cycle_count();
-        result ^= REG_READ(WDEV_RND_REG);
-    } while (ccount - last_ccount < cpu_to_apb_freq_ratio * 16);
-    last_ccount = ccount;
-    return result ^ REG_READ(WDEV_RND_REG);
-}
-
-void esp_fill_random(void *buf, size_t len)
-{
-    assert(buf != NULL);
-    uint8_t *buf_bytes = (uint8_t *)buf;
-    while (len > 0) {
-        uint32_t word = esp_random();
-        uint32_t to_copy = MIN(sizeof(word), len);
-        memcpy(buf_bytes, &word, to_copy);
-        buf_bytes += to_copy;
-        len -= to_copy;
-    }
-}

components/esp32s2/CMakeLists.txt

@@ -16,7 +16,6 @@ else()
              "clk.c"
              "crosscore_int.c"
              "dport_access.c"
-             "hw_random.c"
              "spiram.c"
              "spiram_psram.c"
              "system_api_esp32s2.c"

components/esp32s2/test/test_random.c

@@ -1,66 +0,0 @@
-#include <stdio.h>
-#include <string.h>
-#include "unity.h"
-#include "esp_system.h"
-
-/* Note: these are just sanity tests, not the same as
-   entropy tests
-*/
-
-TEST_CASE("call esp_random()", "[random]")
-{
-    const size_t NUM_RANDOM = 128; /* in most cases this is massive overkill */
-
-    uint32_t zeroes = UINT32_MAX;
-    uint32_t ones = 0;
-    for (int i = 0; i < NUM_RANDOM - 1; i++) {
-        uint32_t r = esp_random();
-        ones |= r;
-        zeroes &= ~r;
-    }
-
-    /* assuming a 'white' random distribution, we can expect
-       usually at least one time each bit will be zero and at
-       least one time each will be one. Statistically this
-       can still fail, just *very* unlikely to. */
-    TEST_ASSERT_EQUAL_HEX32(0, zeroes);
-    TEST_ASSERT_EQUAL_HEX32(UINT32_MAX, ones);
-}
-
-TEST_CASE("call esp_fill_random()", "[random]")
-{
-    const size_t NUM_BUF = 200;
-    const size_t BUF_SZ = 16;
-    uint8_t buf[NUM_BUF][BUF_SZ];
-    uint8_t zero_buf[BUF_SZ];
-    uint8_t one_buf[BUF_SZ];
-
-    bzero(buf, sizeof(buf));
-    bzero(one_buf, sizeof(zero_buf));
-    memset(zero_buf, 0xFF, sizeof(one_buf));
-
-    for (int i = 0; i < NUM_BUF; i++) {
-        esp_fill_random(buf[i], BUF_SZ);
-    }
-    /* No two 128-bit buffers should be the same
-       (again, statistically this could happen but it's very unlikely) */
-    for (int i = 0; i < NUM_BUF; i++) {
-        for (int j = 0; j < NUM_BUF; j++) {
-            if (i != j) {
-                TEST_ASSERT_NOT_EQUAL(0, memcmp(buf[i], buf[j], BUF_SZ));
-            }
-        }
-    }
-
-    /* Do the same all bits are zero and one at least once test across the buffers */
-    for (int i = 0; i < NUM_BUF; i++) {
-        for (int x = 0; x < BUF_SZ; x++) {
-            zero_buf[x] &= ~buf[i][x];
-            one_buf[x] |= buf[i][x];
-        }
-    }
-    for (int x = 0; x < BUF_SZ; x++) {
-        TEST_ASSERT_EQUAL_HEX8(0, zero_buf[x]);
-        TEST_ASSERT_EQUAL_HEX8(0xFF, one_buf[x]);
-    }
-}

components/esp32s3/CMakeLists.txt

@@ -17,7 +17,6 @@ else()
              "crosscore_int.c"
              "dport_access.c"
              "esp_crypto_lock.c"
-             "hw_random.c"
 
              "memprot.c"
              "spiram.c"

components/esp32s3/hw_random.c

@@ -1,69 +0,0 @@
-// Copyright 2020 Espressif Systems (Shanghai) PTE LTD
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-
-#include <stdint.h>
-#include <stddef.h>
-#include <string.h>
-#include <sys/param.h>
-#include "esp_attr.h"
-#include "hal/cpu_hal.h"
-#include "esp32s3/clk.h"
-#include "soc/wdev_reg.h"
-
-uint32_t IRAM_ATTR esp_random(void)
-{
-    /* The PRNG which implements WDEV_RANDOM register gets 2 bits
-     * of extra entropy from a hardware randomness source every APB clock cycle
-     * (provided WiFi or BT are enabled). To make sure entropy is not drained
-     * faster than it is added, this function needs to wait for at least 16 APB
-     * clock cycles after reading previous word. This implementation may actually
-     * wait a bit longer due to extra time spent in arithmetic and branch statements.
-     *
-     * As a (probably unncessary) precaution to avoid returning the
-     * RNG state as-is, the result is XORed with additional
-     * WDEV_RND_REG reads while waiting.
-     */
-
-    /* This code does not run in a critical section, so CPU frequency switch may
-     * happens while this code runs (this will not happen in the current
-     * implementation, but possible in the future). However if that happens,
-     * the number of cycles spent on frequency switching will certainly be more
-     * than the number of cycles we need to wait here.
-     */
-    uint32_t cpu_to_apb_freq_ratio = esp_clk_cpu_freq() / esp_clk_apb_freq();
-
-    static uint32_t last_ccount = 0;
-    uint32_t ccount;
-    uint32_t result = 0;
-    do {
-        ccount = cpu_hal_get_cycle_count();
-        result ^= REG_READ(WDEV_RND_REG);
-    } while (ccount - last_ccount < cpu_to_apb_freq_ratio * 16);
-    last_ccount = ccount;
-    return result ^ REG_READ(WDEV_RND_REG);
-}
-
-void esp_fill_random(void *buf, size_t len)
-{
-    assert(buf != NULL);
-    uint8_t *buf_bytes = (uint8_t *)buf;
-    while (len > 0) {
-        uint32_t word = esp_random();
-        uint32_t to_copy = MIN(sizeof(word), len);
-        memcpy(buf_bytes, &word, to_copy);
-        buf_bytes += to_copy;
-        len -= to_copy;
-    }
-}

components/esp_hw_support/CMakeLists.txt

@@ -7,7 +7,7 @@ endif()
 
 set(srcs "compare_set.c" "cpu_util.c")
 if(NOT BOOTLOADER_BUILD)
-    list(APPEND srcs "clk_ctrl_os.c" "mac_addr.c")
+    list(APPEND srcs "clk_ctrl_os.c" "mac_addr.c" "hw_random.c")
 endif()
 
 idf_component_register(SRCS ${srcs}

components/esp32s2/hw_random.c → components/esp_hw_support/hw_random.c

@@ -19,9 +19,18 @@
 #include <sys/param.h>
 #include "esp_attr.h"
 #include "hal/cpu_hal.h"
-#include "esp32s2/clk.h"
 #include "soc/wdev_reg.h"
 
+#if CONFIG_IDF_TARGET_ESP32
+#include "esp32/clk.h"
+#elif CONFIG_IDF_TARGET_ESP32S2
+#include "esp32s2/clk.h"
+#elif CONFIG_IDF_TARGET_ESP32S3
+#include "esp32s3/clk.h"
+#elif CONFIG_IDF_TARGET_ESP32C3
+#include "esp32c3/clk.h"
+#endif
+
 uint32_t IRAM_ATTR esp_random(void)
 {
     /* The PRNG which implements WDEV_RANDOM register gets 2 bits