Flash: make btldr check/reset the copy FW flag in user flash space

e4909f3a · Christos Gentsos · 79fccc98 · e4909f3a · e4909f3a · e4909f3a
Commit e4909f3a authored Jul 29, 2019 by Christos Gentsos
5 changed files
--- a/main_fw/atmel_start_prj/samd21a/gcc/gcc/samd21g18a_flash.ld
+++ b/main_fw/atmel_start_prj/samd21a/gcc/gcc/samd21g18a_flash.ld
@@ -35,7 +35,8 @@ SEARCH_DIR(.)
 /* Memory Spaces Definitions */
 MEMORY
 {
-  bootloader (rx)  : ORIGIN = 0x00000000, LENGTH = 0x00002000
+  bootloader (rx)  : ORIGIN = 0x00000000, LENGTH = 0x00001f00
+  user_flash (rx)  : ORIGIN = 0x00001f00, LENGTH = 0x00000100
  fw_storage (rx)  : ORIGIN = 0x00022000, LENGTH = 0x0001c000
  ram        (rwx) : ORIGIN = 0x20000000, LENGTH = 0x00008000
 }
@@ -111,6 +112,14 @@ SECTIONS
        _emockbl = .;
    } > bootloader

+    .user_flash :
+    {
+        . = ALIGN(4);
+        user_flash = .;
+        LONG(0xBEC0ABCD)
+        . = ALIGN(4);
+    } > user_flash
+
    .relocate : AT (_etext)
    {
        . = ALIGN(4);

--- a/main_fw/atmel_start_prj/samd21a/gcc/gcc/samd21g18a_flash_mockbl.ld
+++ b/main_fw/atmel_start_prj/samd21a/gcc/gcc/samd21g18a_flash_mockbl.ld
@@ -35,7 +35,7 @@ SEARCH_DIR(.)
 /* Memory Spaces Definitions */
 MEMORY
 {
-  bootloader (rx)  : ORIGIN = 0x00000000, LENGTH = 0x00002000
+  bootloader (rx)  : ORIGIN = 0x00000000, LENGTH = 0x00001f00
  ram        (rwx) : ORIGIN = 0x20000000, LENGTH = 0x00008000
 }

@@ -97,6 +97,8 @@ SECTIONS
    . = ALIGN(4);
    _etext = .;

+    user_flash = LENGTH(bootloader);
+
    .relocate : AT (_etext)
    {
        . = ALIGN(4);

--- a/main_fw/src/flash_utils.h
+++ b/main_fw/src/flash_utils.h
@@ -3,6 +3,15 @@

 #define FLASH_ROW_SIZE 256

+
+typedef struct {
+        uint32_t copy_fw;
+        uint8_t user_data[252];
+} user_flash_t;
+
+extern user_flash_t user_flash;
+
+
 void flash_erase_row(uint32_t *dst);

 void flash_write_words(uint32_t *dst, uint32_t *src, uint32_t n_words);

--- a/main_fw/src/i2c_slave.c
+++ b/main_fw/src/i2c_slave.c
@@ -42,11 +42,11 @@ static addr_space_t regs = {.n_addrs = N_REGS,
                            .i2c_reg_w_callback = (fp_t[N_REGS]){},
                            .i2c_reg_r_callback = (fp_t[N_REGS]){}};

-#define N_EXT_REGS 4
+#define N_EXT_REGS 6

 static addr_space_t ext_regs = {.n_addrs = N_EXT_REGS,
-                                .i2c_reg_addrs = (uint8_t[N_EXT_REGS]){1, 2, 3, 4},
-                                .i2c_reg_lengths = (uint8_t[N_EXT_REGS]){2, 8, 2, 1},
+                                .i2c_reg_addrs = (uint8_t[N_EXT_REGS]){1, 2, 3, 4, 5, 6},
+                                .i2c_reg_lengths = (uint8_t[N_EXT_REGS]){2, 8, 2, 1, 1, 1},
                                .i2c_reg_pointers = (uint8_t*[N_EXT_REGS]){},
                                .i2c_reg_w_callback = (fp_t[N_REGS]){},
                                .i2c_reg_r_callback = (fp_t[N_REGS]){}};
@@ -288,14 +288,18 @@ void written_fw_checksum()
 }


-void print_checksum_and_goto_bootloader()
+void print_checksum()
 {
        if (fw_local_checksum == *(uint16_t *)(&ext_regs.i2c_reg_pointers[2][0])) {
                debug("locally computed checksum %u is correct!", fw_local_checksum);
        } else {
                debug("locally computed checksum %u differs from %u!", fw_local_checksum, *(uint16_t *)(&ext_regs.i2c_reg_pointers[2][0]));
        }
+}
+

+void uc_reset()
+{
        usbdc_detach();
        usbdc_stop();
        usbdc_deinit();
@@ -304,6 +308,26 @@ void print_checksum_and_goto_bootloader()
 }


+void boot_new_fw()
+{
+        uint8_t *char_user_flash = (uint8_t *)&user_flash;
+        user_flash_t *tmp_user_flash = (user_flash_t *)fw_write_buf;
+
+        /* backup existing user data */
+        for (uint8_t i = 0; i < 8; ++i)
+                fw_write_buf[i] = char_user_flash[i];
+
+        /* set 0xBEC0ABCD copy FW code */
+        tmp_user_flash->copy_fw = 0xbec0abcd;
+
+        /* copy modified block back to the flash */
+        flash_write_row((uint32_t *)&user_flash, (uint32_t *)fw_write_buf);
+
+        /* reset the uC */
+        uc_reset();
+}
+
+
 void setup_I2C_slave(void)
 {
        init_addr_space(&regs);
@@ -312,7 +336,9 @@ void setup_I2C_slave(void)
        regs.i2c_reg_pointers[3][1] = 0xad;
        ext_regs.i2c_reg_w_callback[1] = &written_fw_block;
        ext_regs.i2c_reg_w_callback[2] = &written_fw_checksum;
-        ext_regs.i2c_reg_w_callback[3] = &print_checksum_and_goto_bootloader;
+        ext_regs.i2c_reg_w_callback[3] = &print_checksum;
+        ext_regs.i2c_reg_w_callback[4] = &boot_new_fw;
+        ext_regs.i2c_reg_w_callback[5] = &uc_reset;
        fw_write_addr = (uint32_t *)0x22000;
        fw_write_buf = (uint8_t *)malloc(FLASH_ROW_SIZE);
        hri_sercomi2cs_clear_CTRLB_SMEN_bit(SERCOM3);

--- a/main_fw/src/main_mockbl.c
+++ b/main_fw/src/main_mockbl.c
@@ -4,6 +4,8 @@

 #define SECOND_APP_START_ADDRESS 0x2000

+static uint8_t tmp_buf[256];
+
 void jump_to_secondary()
 {
        uint32_t app_start_address;
@@ -21,7 +23,23 @@ void jump_to_secondary()

 int main(void)
 {
-        flash_copy((uint32_t*)0x2000, (uint32_t*)0x22000, 0x1e000);
+        if (user_flash.copy_fw == 0xBEC0ABCD) {
+                flash_copy((uint32_t*)0x2000, (uint32_t*)0x22000, 0x1e000);
+
+                uint8_t *char_user_flash = (uint8_t *)&user_flash;
+
+                user_flash_t *tmp_user_flash = (user_flash_t *)tmp_buf;
+
+                /* backup existing user data */
+                for (uint8_t i = 0; i < 8; ++i)
+                        tmp_buf[i] = char_user_flash[i];
+
+                /* reset copy FW code */
+                tmp_user_flash->copy_fw = 0;
+
+                /* copy modified block back to the flash */
+                flash_write_row((uint32_t *)&user_flash, (uint32_t *)tmp_buf);
+        }

        jump_to_secondary();
 }