bootloader: add xmc spi_flash startup flow to improve reliability

components/bootloader/Kconfig.projbuild

@@ -219,6 +219,15 @@ menu "Bootloader config"
             It allow to test anti-rollback implemention without permanent write eFuse bits.
             In partition table should be exist this partition `emul_efuse, data, 5, , 0x2000`.
 
+    config BOOTLOADER_FLASH_XMC_SUPPORT
+        bool "Enable the support for flash chips of XMC (READ HELP FIRST)"
+        default y
+        help
+            Perform the startup flow recommended by XMC. Please consult XMC for the details of this flow.
+            XMC chips will be forbidden to be used, when this option is disabled.
+
+            DON'T DISABLE THIS UNLESS YOU KNOW WHAT YOU ARE DOING.
+
 endmenu  # Bootloader
 
 

components/bootloader_support/include_bootloader/flash_qio_mode.h

@@ -32,6 +32,22 @@ void bootloader_enable_qio_mode(void);
  */
 uint32_t bootloader_read_flash_id();
 
+/**
+ * @brief Read the SFDP of the flash
+ *
+ * @param sfdp_addr Address of the parameter to read
+ * @param miso_byte_num Bytes to read
+ * @return The read SFDP, little endian, 4 bytes at most
+ */
+uint32_t bootloader_flash_read_sfdp(uint32_t sfdp_addr, unsigned int miso_byte_num);
+
+/**
+ * @brief Startup flow recommended by XMC. Call at startup before any erase/write operation.
+ *
+ * @return ESP_OK When startup successfully, otherwise ESP_FAIL (indiciating you should reboot before erase/write).
+ */
+esp_err_t bootloader_flash_xmc_startup(void);
+
 #ifdef __cplusplus
 }
 #endif

components/bootloader_support/src/bootloader_init.c

@@ -122,6 +122,12 @@ static esp_err_t bootloader_main()
     bootloader_common_vddsdio_configure();
     /* Read and keep flash ID, for further use. */
     g_rom_flashchip.device_id = bootloader_read_flash_id();
+    /* Check and run XMC startup flow */
+    if (bootloader_flash_xmc_startup() != ESP_OK) {
+        ESP_LOGE(TAG, "failed when running XMC startup flow, reboot!");
+        return ESP_FAIL;
+    }
+
     esp_image_header_t fhdr;
     if (bootloader_flash_read(ESP_BOOTLOADER_OFFSET, &fhdr, sizeof(esp_image_header_t), true) != ESP_OK) {
         ESP_LOGE(TAG, "failed to load bootloader header!");

components/bootloader_support/src/flash_qio_mode.c

@@ -13,9 +13,11 @@
 // limitations under the License.
 #include <stddef.h>
 #include <stdint.h>
+#include "esp_err.h"
 #include "flash_qio_mode.h"
 #include "esp_log.h"
 #include "esp_err.h"
+#include "esp32/rom/ets_sys.h"
 #include "esp32/rom/spi_flash.h"
 #include "esp32/rom/efuse.h"
 #include "soc/spi_periph.h"
@@ -36,8 +38,12 @@
 #define CMD_RDSR       0x05
 #define CMD_RDSR2      0x35 /* Not all SPI flash uses this command */
 #define CMD_OTPEN      0x3A /* Enable OTP mode, not all SPI flash uses this command */
+#define CMD_RDSFDP     0x5A /* Read the SFDP of the flash */
 
-static const char *TAG = "qio_mode";
+#define BYTESHIFT(VAR, IDX)    (((VAR) >> ((IDX) * 8)) & 0xFF)
+
+
+static DRAM_ATTR char TAG[] = "qio_mode";
 
 typedef unsigned (*read_status_fn_t)();
 typedef void (*write_status_fn_t)(unsigned);
@@ -121,7 +127,7 @@ static uint32_t execute_flash_command(uint8_t command, uint32_t mosi_data, uint8
 
 /* dummy_len_plus values defined in ROM for SPI flash configuration */
 extern uint8_t g_rom_spiflash_dummy_len_plus[];
-uint32_t bootloader_read_flash_id()
+uint32_t IRAM_ATTR bootloader_read_flash_id(void)
 {
     uint32_t id = execute_flash_command(CMD_RDID, 0, 0, 24);
     id = ((id & 0xff) << 16) | ((id >> 16) & 0xff) | (id & 0xff00);
@@ -271,37 +277,188 @@ static void write_status_8b_xmc25qu64a(unsigned new_status)
     execute_flash_command(CMD_WRDI, 0, 0, 0);   /* Exit OTP mode */
 }
 
-static uint32_t execute_flash_command(uint8_t command, uint32_t mosi_data, uint8_t mosi_len, uint8_t miso_len)
+IRAM_ATTR static uint32_t bootloader_flash_execute_command_common(
+    uint8_t command,
+    uint32_t addr_len, uint32_t address,
+    uint8_t dummy_len,
+    uint8_t mosi_len, uint32_t mosi_data,
+    uint8_t miso_len)
 {
+    assert(mosi_len <= 32);
+    assert(miso_len <= 32);
     uint32_t old_ctrl_reg = SPIFLASH.ctrl.val;
     SPIFLASH.ctrl.val = SPI_WP_REG_M; // keep WP high while idle, otherwise leave DIO mode
-    SPIFLASH.user.usr_dummy = 0;
-    SPIFLASH.user.usr_addr = 0;
+    //command phase
     SPIFLASH.user.usr_command = 1;
     SPIFLASH.user2.usr_command_bitlen = 7;
-
     SPIFLASH.user2.usr_command_value = command;
-    SPIFLASH.user.usr_miso = miso_len > 0;
-    SPIFLASH.miso_dlen.usr_miso_dbitlen = miso_len ? (miso_len - 1) : 0;
+    //addr phase
+    SPIFLASH.user.usr_addr = addr_len > 0;
+    SPIFLASH.user1.usr_addr_bitlen = addr_len - 1;
+    SPIFLASH.addr = (addr_len > 0)? (address << (32-addr_len)) : 0;
+    //dummy phase
+    if (miso_len > 0) {
+        uint32_t total_dummy = dummy_len + g_rom_spiflash_dummy_len_plus[1];
+        SPIFLASH.user.usr_dummy = total_dummy > 0;
+        SPIFLASH.user1.usr_dummy_cyclelen = total_dummy - 1;
+    } else {
+        SPIFLASH.user.usr_dummy = 0;
+        SPIFLASH.user1.usr_dummy_cyclelen = 0;
+    }
+    //output data
     SPIFLASH.user.usr_mosi = mosi_len > 0;
     SPIFLASH.mosi_dlen.usr_mosi_dbitlen = mosi_len ? (mosi_len - 1) : 0;
     SPIFLASH.data_buf[0] = mosi_data;
-
-    if (g_rom_spiflash_dummy_len_plus[1]) {
-        /* When flash pins are mapped via GPIO matrix, need a dummy cycle before reading via MISO */
-        if (miso_len > 0) {
-            SPIFLASH.user.usr_dummy = 1;
-            SPIFLASH.user1.usr_dummy_cyclelen = g_rom_spiflash_dummy_len_plus[1] - 1;
-        } else {
-            SPIFLASH.user.usr_dummy = 0;
-            SPIFLASH.user1.usr_dummy_cyclelen = 0;
-        }
-    }
+    //input data
+    SPIFLASH.user.usr_miso = miso_len > 0;
+    SPIFLASH.miso_dlen.usr_miso_dbitlen = miso_len ? (miso_len - 1) : 0;
 
     SPIFLASH.cmd.usr = 1;
     while(SPIFLASH.cmd.usr != 0)
     { }
-
     SPIFLASH.ctrl.val = old_ctrl_reg;
-    return SPIFLASH.data_buf[0];
+
+    uint32_t ret = SPIFLASH.data_buf[0];
+    if (miso_len < 32) {
+        //set unused bits to 0
+        ret &= ~(UINT32_MAX << miso_len);
+    }
+    return ret;
 }
+
+static uint32_t IRAM_ATTR execute_flash_command(uint8_t command, uint32_t mosi_data, uint8_t mosi_len, uint8_t miso_len)
+{
+    const uint8_t addr_len = 0;
+    const uint8_t address = 0;
+    const uint8_t dummy_len = 0;
+
+    return bootloader_flash_execute_command_common(command, addr_len, address,
+            dummy_len, mosi_len, mosi_data, miso_len);
+}
+
+// cmd(0x5A) + 24bit address + 8 cycles dummy
+uint32_t IRAM_ATTR bootloader_flash_read_sfdp(uint32_t sfdp_addr, unsigned int miso_byte_num)
+{
+    assert(miso_byte_num <= 4);
+    const uint8_t command = CMD_RDSFDP;
+    const uint8_t addr_len = 24;
+    const uint8_t dummy_len = 8;
+    const uint8_t mosi_len = 0;
+    const uint32_t mosi_data = 0;
+    const uint8_t miso_len = miso_byte_num * 8;
+
+    return bootloader_flash_execute_command_common(command, addr_len, sfdp_addr,
+            dummy_len, mosi_len, mosi_data, miso_len);
+}
+
+/*******************************************************************************
+ * XMC startup flow
+ ******************************************************************************/
+
+#define XMC_SUPPORT CONFIG_BOOTLOADER_FLASH_XMC_SUPPORT
+#define XMC_VENDOR_ID 0x20
+
+#if BOOTLOADER_BUILD
+#define BOOTLOADER_FLASH_LOG(level, ...)    ESP_LOG##level(TAG, ##__VA_ARGS__)
+#else
+#define BOOTLOADER_FLASH_LOG(level, ...)    ESP_DRAM_LOG##level(TAG, ##__VA_ARGS__)
+
+#define ESP_DRAM_LOGE( tag, format, ... ) ESP_DRAM_LOG_IMPL(tag, format, ESP_LOG_ERROR,   E, ##__VA_ARGS__)
+#define ESP_DRAM_LOGW( tag, format, ... ) ESP_DRAM_LOG_IMPL(tag, format, ESP_LOG_WARN,   E, ##__VA_ARGS__)
+#define ESP_DRAM_LOGI( tag, format, ... ) ESP_DRAM_LOG_IMPL(tag, format, ESP_LOG_INFO,   E, ##__VA_ARGS__)
+#define ESP_DRAM_LOGD( tag, format, ... ) ESP_DRAM_LOG_IMPL(tag, format, ESP_LOG_DEBUG,   E, ##__VA_ARGS__)
+#define ESP_DRAM_LOGV( tag, format, ... ) ESP_DRAM_LOG_IMPL(tag, format, ESP_LOG_VERBOSE,   E, ##__VA_ARGS__)
+
+#define ESP_DRAM_LOG_IMPL(tag, format, log_level, log_tag_letter, ...) do {                       \
+        if (LOG_LOCAL_LEVEL >= (log_level)) {                                                  \
+            ets_printf(DRAM_STR(#log_tag_letter " %s: " format "\n"), tag, ##__VA_ARGS__); \
+        }} while(0)
+
+#endif
+
+#if XMC_SUPPORT
+//strictly check the model
+static IRAM_ATTR bool is_xmc_chip_strict(uint32_t rdid)
+{
+    uint32_t vendor_id = BYTESHIFT(rdid, 2);
+    uint32_t mfid = BYTESHIFT(rdid, 1);
+    uint32_t cpid = BYTESHIFT(rdid, 0);
+
+    if (vendor_id != XMC_VENDOR_ID) {
+        return false;
+    }
+
+    bool matched = false;
+    if (mfid == 0x40) {
+        if (cpid >= 0x13 && cpid <= 0x20) {
+            matched = true;
+        }
+    } else if (mfid == 0x41) {
+        if (cpid >= 0x17 && cpid <= 0x20) {
+            matched = true;
+        }
+    } else if (mfid == 0x50) {
+        if (cpid >= 0x15 && cpid <= 0x16) {
+            matched =  true;
+        }
+    }
+    return matched;
+}
+
+//No log print in normal path, since we are not sure the console is OK at this time
+esp_err_t IRAM_ATTR bootloader_flash_xmc_startup(void)
+{
+    // If the RDID value is a valid XMC one, may skip the flow
+    const bool fast_check = true;
+    if (fast_check && is_xmc_chip_strict(g_rom_flashchip.device_id)) {
+        return ESP_OK;
+    }
+
+    // Check the Manufacturer ID in SFDP registers (JEDEC standard). If not XMC chip, no need to run the flow
+    const int sfdp_mfid_addr = 0x10;
+    uint8_t mf_id = (bootloader_flash_read_sfdp(sfdp_mfid_addr, 1) & 0xff);
+    if (mf_id != XMC_VENDOR_ID) {
+        return ESP_OK;
+    }
+
+    //XM25QHxxC startup flow
+    // Enter DPD
+    execute_flash_command(0xB9, 0, 0, 0);
+    // Enter UDPD
+    execute_flash_command(0x79, 0, 0, 0);
+    // Exit UDPD
+    execute_flash_command(0xFF, 0, 0, 0);
+    // Delay tXUDPD
+    ets_delay_us(2000);
+    // Release Power-down
+    execute_flash_command(0xAB, 0, 0, 0);
+    ets_delay_us(20);
+    // Read flash ID and check again
+    g_rom_flashchip.device_id = bootloader_read_flash_id();
+    if (!is_xmc_chip_strict(g_rom_flashchip.device_id)) {
+        BOOTLOADER_FLASH_LOG(E, "XMC flash startup fail");
+        return ESP_FAIL;
+    }
+
+    return ESP_OK;
+}
+
+#else
+//only compare the vendor id
+static IRAM_ATTR bool is_xmc_chip(uint32_t rdid)
+{
+    uint32_t vendor_id = (rdid >> 16) & 0xFF;
+    return (vendor_id == XMC_VENDOR_ID);
+}
+
+esp_err_t IRAM_ATTR bootloader_flash_xmc_startup(void)
+{
+    if (is_xmc_chip(g_rom_flashchip.device_id)) {
+        BOOTLOADER_FLASH_LOG(E, "XMC chip detected (%08X) while support disabled.", g_rom_flashchip.device_id);
+        return ESP_FAIL;
+    }
+    return ESP_OK;
+}
+
+#endif //XMC_SUPPORT
+

components/spi_flash/test/test_spi_flash.c

@@ -11,6 +11,8 @@
 #include "esp_intr_alloc.h"
 #include "test_utils.h"
 #include "esp_log.h"
+#include "../include_bootloader/flash_qio_mode.h"   //for bootloader_flash_xmc_startup
+
 
 struct flash_test_ctx {
     uint32_t offset;
@@ -352,3 +354,22 @@ TEST_CASE("spi_flash deadlock with high priority busy-waiting task", "[spi_flash
     TEST_ASSERT_EQUAL_INT(uxTaskPriorityGet(NULL), UNITY_FREERTOS_PRIORITY);
 }
 #endif // portNUM_PROCESSORS > 1
+
+
+static IRAM_ATTR NOINLINE_ATTR void test_xmc_startup(void)
+{
+    extern void spi_flash_disable_interrupts_caches_and_other_cpu(void);
+    extern void spi_flash_enable_interrupts_caches_and_other_cpu(void);
+    esp_err_t ret = ESP_OK;
+
+    spi_flash_disable_interrupts_caches_and_other_cpu();
+    ret = bootloader_flash_xmc_startup();
+    spi_flash_enable_interrupts_caches_and_other_cpu();
+
+    TEST_ASSERT_EQUAL(ESP_OK, ret);
+}
+
+TEST_CASE("bootloader_flash_xmc_startup can be called when cache disabled", "[spi_flash]")
+{
+    test_xmc_startup();
+}