]> git.zerfleddert.de Git - proxmark3-svn/blobdiff - bootrom/bootrom.c
minor fix when reading blocks
[proxmark3-svn] / bootrom / bootrom.c
index c8c695cc9f6c097b4b7b4f70771ff02711e0c7b6..fc1c8a2c55c82d59d4b34d010543ecee2fca6596 100644 (file)
-#include <proxmark3.h>\r
-\r
-struct common_area common_area __attribute__((section(".commonarea")));\r
-unsigned int start_addr, end_addr, bootrom_unlocked; \r
-extern char _bootrom_start, _bootrom_end, _flash_start, _flash_end;\r
-\r
-static void ConfigClocks(void)\r
-{\r
-    // we are using a 16 MHz crystal as the basis for everything\r
-    // slow clock runs at 32Khz typical regardless of crystal\r
-\r
-    // enable system clock and USB clock\r
-    PMC_SYS_CLK_ENABLE = PMC_SYS_CLK_PROCESSOR_CLK | PMC_SYS_CLK_UDP_CLK;\r
-\r
-       // enable the clock to the following peripherals\r
-    PMC_PERIPHERAL_CLK_ENABLE =\r
-        (1<<PERIPH_PIOA) |\r
-        (1<<PERIPH_ADC) |\r
-        (1<<PERIPH_SPI) |\r
-        (1<<PERIPH_SSC) |\r
-        (1<<PERIPH_PWMC) |\r
-        (1<<PERIPH_UDP);\r
-\r
-       // worst case scenario, with 16Mhz xtal startup delay is 14.5ms\r
-       // with a slow clock running at it worst case (max) frequency of 42khz\r
-       // max startup delay = (14.5ms*42k)/8 = 76 = 0x4C round up to 0x50\r
-\r
-       // enable main oscillator and set startup delay\r
-    PMC_MAIN_OSCILLATOR = PMC_MAIN_OSCILLATOR_ENABLE |\r
-        PMC_MAIN_OSCILLATOR_STARTUP_DELAY(0x50);\r
-\r
-       // wait for main oscillator to stabilize\r
-       while ( !(PMC_INTERRUPT_STATUS & PMC_MAIN_OSCILLATOR_STABILIZED) )\r
-               ;\r
-\r
-    // minimum PLL clock frequency is 80 MHz in range 00 (96 here so okay)\r
-    // frequency is crystal * multiplier / divisor = 16Mhz * 12 / 2 = 96Mhz\r
-    PMC_PLL = PMC_PLL_DIVISOR(2) | PMC_PLL_COUNT_BEFORE_LOCK(0x50) |\r
-        PMC_PLL_FREQUENCY_RANGE(0) | PMC_PLL_MULTIPLIER(12) |\r
-        PMC_PLL_USB_DIVISOR(1);\r
-\r
-       // wait for PLL to lock\r
-       while ( !(PMC_INTERRUPT_STATUS & PMC_MAIN_OSCILLATOR_PLL_LOCK) )\r
-               ;\r
-\r
-       // we want a master clock (MCK) to be PLL clock / 2 = 96Mhz / 2 = 48Mhz\r
-       // as per datasheet, this register must be programmed in two operations\r
-       // when changing to PLL, program the prescaler first then the source\r
-    PMC_MASTER_CLK = PMC_CLK_PRESCALE_DIV_2;\r
-\r
-       // wait for main clock ready signal\r
-       while ( !(PMC_INTERRUPT_STATUS & PMC_MAIN_OSCILLATOR_MCK_READY) )\r
-               ;\r
-\r
-       // set the source to PLL\r
-    PMC_MASTER_CLK = PMC_CLK_SELECTION_PLL_CLOCK | PMC_CLK_PRESCALE_DIV_2;\r
-\r
-       // wait for main clock ready signal\r
-       while ( !(PMC_INTERRUPT_STATUS & PMC_MAIN_OSCILLATOR_MCK_READY) )\r
-               ;\r
-}\r
-\r
-static void Fatal(void)\r
-{\r
-    for(;;);\r
-}\r
-\r
-void UsbPacketReceived(BYTE *packet, int len)\r
-{\r
-    int i, dont_ack=0;\r
-    UsbCommand *c = (UsbCommand *)packet;\r
-    volatile DWORD *p;\r
-\r
-    if(len != sizeof(*c)) {\r
-        Fatal();\r
-    }\r
-\r
-    switch(c->cmd) {\r
-        case CMD_DEVICE_INFO:\r
-            dont_ack = 1;\r
-            c->cmd = CMD_DEVICE_INFO;\r
-            c->ext1 = DEVICE_INFO_FLAG_BOOTROM_PRESENT | DEVICE_INFO_FLAG_CURRENT_MODE_BOOTROM | \r
-                DEVICE_INFO_FLAG_UNDERSTANDS_START_FLASH;\r
-            if(common_area.flags.osimage_present) c->ext1 |= DEVICE_INFO_FLAG_OSIMAGE_PRESENT;\r
-            UsbSendPacket(packet, len);\r
-            break;\r
-\r
-        case CMD_SETUP_WRITE:\r
-            /* The temporary write buffer of the embedded flash controller is mapped to the\r
+//-----------------------------------------------------------------------------
+// This code is licensed to you under the terms of the GNU GPL, version 2 or,
+// at your option, any later version. See the LICENSE.txt file for the text of
+// the license.
+//-----------------------------------------------------------------------------
+// Main code for the bootloader
+//-----------------------------------------------------------------------------
+
+#include <proxmark3.h>
+#include "usb_hid.h"
+
+struct common_area common_area __attribute__((section(".commonarea")));
+unsigned int start_addr, end_addr, bootrom_unlocked;
+extern char _bootrom_start, _bootrom_end, _flash_start, _flash_end;
+
+static void ConfigClocks(void)
+{
+    // we are using a 16 MHz crystal as the basis for everything
+    // slow clock runs at 32Khz typical regardless of crystal
+
+    // enable system clock and USB clock
+    AT91C_BASE_PMC->PMC_SCER = AT91C_PMC_PCK | AT91C_PMC_UDP;
+
+       // enable the clock to the following peripherals
+    AT91C_BASE_PMC->PMC_PCER =
+               (1<<AT91C_ID_PIOA)      |
+               (1<<AT91C_ID_ADC)       |
+               (1<<AT91C_ID_SPI)       |
+               (1<<AT91C_ID_SSC)       |
+               (1<<AT91C_ID_PWMC)      |
+               (1<<AT91C_ID_UDP);
+
+       // worst case scenario, with MAINCK = 16Mhz xtal, startup delay is 1.4ms
+       // if SLCK slow clock runs at its worst case (max) frequency of 42khz
+       // max startup delay = (1.4ms*42k)/8 = 7.356 so round up to 8
+
+       // enable main oscillator and set startup delay
+    AT91C_BASE_PMC->PMC_MOR =
+        AT91C_CKGR_MOSCEN |
+        PMC_MAIN_OSC_STARTUP_DELAY(8);
+
+       // wait for main oscillator to stabilize
+       while ( !(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MOSCS) )
+               ;
+
+    // PLL output clock frequency in range  80 - 160 MHz needs CKGR_PLL = 00
+    // PLL output clock frequency in range 150 - 180 MHz needs CKGR_PLL = 10
+    // PLL output is MAINCK * multiplier / divisor = 16Mhz * 12 / 2 = 96Mhz
+    AT91C_BASE_PMC->PMC_PLLR =
+       PMC_PLL_DIVISOR(2) |
+               PMC_PLL_COUNT_BEFORE_LOCK(0x50) |
+               PMC_PLL_FREQUENCY_RANGE(0) |
+               PMC_PLL_MULTIPLIER(12) |
+               PMC_PLL_USB_DIVISOR(1);
+
+       // wait for PLL to lock
+       while ( !(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCK) )
+               ;
+
+       // we want a master clock (MCK) to be PLL clock / 2 = 96Mhz / 2 = 48Mhz
+       // datasheet recommends that this register is programmed in two operations
+       // when changing to PLL, program the prescaler first then the source
+    AT91C_BASE_PMC->PMC_MCKR = AT91C_PMC_PRES_CLK_2;
+
+       // wait for main clock ready signal
+       while ( !(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY) )
+               ;
+
+       // set the source to PLL
+    AT91C_BASE_PMC->PMC_MCKR = AT91C_PMC_PRES_CLK_2 | AT91C_PMC_CSS_PLL_CLK;
+
+       // wait for main clock ready signal
+       while ( !(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY) )
+               ;
+}
+
+static void Fatal(void)
+{
+    for(;;);
+}
+
+void UsbPacketReceived(uint8_t *packet, int len)
+{
+    int i, dont_ack=0;
+    UsbCommand *c = (UsbCommand *)packet;
+    volatile uint32_t *p;
+
+    if(len != sizeof(*c)) {
+        Fatal();
+    }
+
+    switch(c->cmd) {
+        case CMD_DEVICE_INFO:
+            dont_ack = 1;
+            c->cmd = CMD_DEVICE_INFO;
+            c->arg[0] = DEVICE_INFO_FLAG_BOOTROM_PRESENT | DEVICE_INFO_FLAG_CURRENT_MODE_BOOTROM |
+                DEVICE_INFO_FLAG_UNDERSTANDS_START_FLASH;
+            if(common_area.flags.osimage_present) c->arg[0] |= DEVICE_INFO_FLAG_OSIMAGE_PRESENT;
+            UsbSendPacket(packet, len);
+            break;
+
+        case CMD_SETUP_WRITE:
+            /* The temporary write buffer of the embedded flash controller is mapped to the
              * whole memory region, only the last 8 bits are decoded.
-             */\r
-            p = (volatile DWORD *)&_flash_start;\r
-            for(i = 0; i < 12; i++) {\r
-                p[i+c->ext1] = c->d.asDwords[i];\r
-            }\r
-            break;\r
-\r
-        case CMD_FINISH_WRITE:\r
-            p = (volatile DWORD *)&_flash_start;\r
-            for(i = 0; i < 4; i++) {\r
-                p[i+60] = c->d.asDwords[i];\r
-            }\r
-\r
-            /* Check that the address that we are supposed to write to is within our allowed region */\r
-            if( ((c->ext1+FLASH_PAGE_SIZE_BYTES-1) >= end_addr) || (c->ext1 < start_addr) ) {\r
-                /* Disallow write */\r
-                dont_ack = 1;\r
-                c->cmd = CMD_NACK;\r
-                UsbSendPacket(packet, len);\r
-            } else {\r
-                /* Translate address to flash page and do flash, update here for the 512k part */\r
-                MC_FLASH_COMMAND = MC_FLASH_COMMAND_KEY |\r
-                    MC_FLASH_COMMAND_PAGEN((c->ext1-(int)&_flash_start)/FLASH_PAGE_SIZE_BYTES) |\r
-                    FCMD_WRITE_PAGE;\r
-            }\r
-            while(!(MC_FLASH_STATUS & MC_FLASH_STATUS_READY))\r
-                ;\r
-            break;\r
-\r
-        case CMD_HARDWARE_RESET:\r
-            USB_D_PLUS_PULLUP_OFF();\r
-            RSTC_CONTROL = RST_CONTROL_KEY | RST_CONTROL_PROCESSOR_RESET;\r
-            break;\r
-        \r
-        case CMD_START_FLASH:\r
-            if(c->ext3 == START_FLASH_MAGIC) bootrom_unlocked = 1;\r
-            else bootrom_unlocked = 0;\r
-            {\r
-                int prot_start = (int)&_bootrom_start;\r
-                int prot_end = (int)&_bootrom_end;\r
-                int allow_start = (int)&_flash_start;\r
-                int allow_end = (int)&_flash_end;\r
-                int cmd_start = c->ext1;\r
-                int cmd_end = c->ext2;\r
-                \r
-                /* Only allow command if the bootrom is unlocked, or the parameters are outside of the protected\r
+             */
+            p = (volatile uint32_t *)&_flash_start;
+            for(i = 0; i < 12; i++) {
+                p[i+c->arg[0]] = c->d.asDwords[i];
+            }
+            break;
+
+        case CMD_FINISH_WRITE:
+            p = (volatile uint32_t *)&_flash_start;
+            for(i = 0; i < 4; i++) {
+                p[i+60] = c->d.asDwords[i];
+            }
+
+            /* Check that the address that we are supposed to write to is within our allowed region */
+            if( ((c->arg[0]+AT91C_IFLASH_PAGE_SIZE-1) >= end_addr) || (c->arg[0] < start_addr) ) {
+                /* Disallow write */
+                dont_ack = 1;
+                c->cmd = CMD_NACK;
+                UsbSendPacket(packet, len);
+            } else {
+                /* Translate address to flash page and do flash, update here for the 512k part */
+                AT91C_BASE_EFC0->EFC_FCR = MC_FLASH_COMMAND_KEY |
+                    MC_FLASH_COMMAND_PAGEN((c->arg[0]-(int)&_flash_start)/AT91C_IFLASH_PAGE_SIZE) |
+                    AT91C_MC_FCMD_START_PROG;
+            }
+
+            uint32_t sr;
+
+            while(!((sr = AT91C_BASE_EFC0->EFC_FSR) & AT91C_MC_FRDY))
+                ;
+            if(sr & (AT91C_MC_LOCKE | AT91C_MC_PROGE)) {
+                   dont_ack = 1;
+                    c->cmd = CMD_NACK;
+                    UsbSendPacket(packet, len);
+            }
+            break;
+
+        case CMD_HARDWARE_RESET:
+            USB_D_PLUS_PULLUP_OFF();
+            AT91C_BASE_RSTC->RSTC_RCR = RST_CONTROL_KEY | AT91C_RSTC_PROCRST;
+            break;
+
+        case CMD_START_FLASH:
+            if(c->arg[2] == START_FLASH_MAGIC) bootrom_unlocked = 1;
+            else bootrom_unlocked = 0;
+            {
+                int prot_start = (int)&_bootrom_start;
+                int prot_end = (int)&_bootrom_end;
+                int allow_start = (int)&_flash_start;
+                int allow_end = (int)&_flash_end;
+                int cmd_start = c->arg[0];
+                int cmd_end = c->arg[1];
+
+                /* Only allow command if the bootrom is unlocked, or the parameters are outside of the protected
                  * bootrom area. In any case they must be within the flash area.
-                 */\r
-                if( (bootrom_unlocked || ((cmd_start >= prot_end) || (cmd_end < prot_start)))\r
-                    && (cmd_start >= allow_start) && (cmd_end <= allow_end) ) {\r
-                    start_addr = cmd_start;\r
-                    end_addr = cmd_end;\r
-                } else {\r
-                    start_addr = end_addr = 0;\r
-                    dont_ack = 1;\r
-                    c->cmd = CMD_NACK;\r
-                    UsbSendPacket(packet, len);\r
-                }\r
-            }\r
-            break;\r
-        \r
-        default:\r
-            Fatal();\r
-            break;\r
-    }\r
-\r
-    if(!dont_ack) {\r
-        c->cmd = CMD_ACK;\r
-        UsbSendPacket(packet, len);\r
-    }\r
-}\r
-\r
-static void flash_mode(int externally_entered)\r
-{\r
-       start_addr = 0;\r
-       end_addr = 0;\r
-       bootrom_unlocked = 0;\r
-       \r
-       UsbStart();\r
-       for(;;) {\r
-               WDT_HIT();\r
-               \r
-               UsbPoll(TRUE);\r
-               \r
-               if(!externally_entered && !BUTTON_PRESS()) {\r
-                       /* Perform a reset to leave flash mode */\r
-                       USB_D_PLUS_PULLUP_OFF();\r
-                       LED_B_ON();\r
-                       RSTC_CONTROL = RST_CONTROL_KEY | RST_CONTROL_PROCESSOR_RESET;\r
-                       for(;;);\r
-               }\r
-               if(externally_entered && BUTTON_PRESS()) {\r
-                       /* Let the user's button press override the automatic leave */\r
-                       externally_entered = 0;\r
-               }\r
-       }\r
-}\r
-\r
-extern char _osimage_entry;\r
-void BootROM(void)\r
-{\r
-    //------------\r
-    // First set up all the I/O pins; GPIOs configured directly, other ones\r
-    // just need to be assigned to the appropriate peripheral.\r
-\r
-    // Kill all the pullups, especially the one on USB D+; leave them for\r
-    // the unused pins, though.\r
-    PIO_NO_PULL_UP_ENABLE =     (1 << GPIO_USB_PU)          |\r
-                                (1 << GPIO_LED_A)           |\r
-                                (1 << GPIO_LED_B)           |\r
-                                (1 << GPIO_LED_C)           |\r
-                                (1 << GPIO_LED_D)           |\r
-                                (1 << GPIO_FPGA_DIN)        |\r
-                                (1 << GPIO_FPGA_DOUT)       |\r
-                                (1 << GPIO_FPGA_CCLK)       |\r
-                                (1 << GPIO_FPGA_NINIT)      |\r
-                                (1 << GPIO_FPGA_NPROGRAM)   |\r
-                                (1 << GPIO_FPGA_DONE)       |\r
-                                (1 << GPIO_MUXSEL_HIPKD)    |\r
-                                (1 << GPIO_MUXSEL_HIRAW)    |\r
-                                (1 << GPIO_MUXSEL_LOPKD)    |\r
-                                (1 << GPIO_MUXSEL_LORAW)    |\r
-                                (1 << GPIO_RELAY)              |\r
-                                (1 << GPIO_NVDD_ON);\r
-                                // (and add GPIO_FPGA_ON)\r
-       // These pins are outputs\r
-    PIO_OUTPUT_ENABLE =         (1 << GPIO_LED_A)           |\r
-                                (1 << GPIO_LED_B)           |\r
-                                (1 << GPIO_LED_C)           |\r
-                                (1 << GPIO_LED_D)           |\r
-                                (1 << GPIO_RELAY)              |\r
-                                (1 << GPIO_NVDD_ON);\r
-       // PIO controls the following pins\r
-    PIO_ENABLE =                (1 << GPIO_USB_PU)          |\r
-                                (1 << GPIO_LED_A)           |\r
-                                (1 << GPIO_LED_B)           |\r
-                                (1 << GPIO_LED_C)           |\r
-                                (1 << GPIO_LED_D);\r
-\r
-    USB_D_PLUS_PULLUP_OFF();\r
-    LED_D_OFF();\r
-    LED_C_ON();\r
-    LED_B_OFF();\r
-    LED_A_OFF();\r
-    \r
-    // if 512K FLASH part - TODO make some defines :)\r
-    if ((DBGU_CIDR | 0xf00) == 0xa00) {\r
-           MC_FLASH_MODE0 = MC_FLASH_MODE_FLASH_WAIT_STATES(1) |\r
-           MC_FLASH_MODE_MASTER_CLK_IN_MHZ(0x48);\r
-           MC_FLASH_MODE1 = MC_FLASH_MODE_FLASH_WAIT_STATES(1) |\r
-           MC_FLASH_MODE_MASTER_CLK_IN_MHZ(0x48);\r
-    } else {\r
-           MC_FLASH_MODE0 = MC_FLASH_MODE_FLASH_WAIT_STATES(0) |\r
-           MC_FLASH_MODE_MASTER_CLK_IN_MHZ(48);\r
-    }\r
-    \r
-    // Initialize all system clocks\r
-    ConfigClocks();\r
-    \r
-    LED_A_ON();\r
-    \r
-    int common_area_present = 0;\r
-    switch(RSTC_STATUS & RST_STATUS_TYPE_MASK) {\r
-    case RST_STATUS_TYPE_WATCHDOG:\r
-    case RST_STATUS_TYPE_SOFTWARE:\r
-    case RST_STATUS_TYPE_USER:\r
-           /* In these cases the common_area in RAM should be ok, retain it if it's there */\r
-           if(common_area.magic == COMMON_AREA_MAGIC && common_area.version == 1) {\r
-                   common_area_present = 1;\r
-           }\r
-           break;\r
-    default: /* Otherwise, initialize it from scratch */\r
-           break;\r
-    }\r
-    \r
-    if(!common_area_present){\r
-           /* Common area not ok, initialize it */\r
-           int i; for(i=0; i<sizeof(common_area); i++) { /* Makeshift memset, no need to drag util.c into this */\r
-                   ((char*)&common_area)[i] = 0;\r
-           }\r
-           common_area.magic = COMMON_AREA_MAGIC;\r
-           common_area.version = 1;\r
-           common_area.flags.bootrom_present = 1;\r
-    }\r
-    \r
-    common_area.flags.bootrom_present = 1;\r
-    if(common_area.command == COMMON_AREA_COMMAND_ENTER_FLASH_MODE) {\r
-           common_area.command = COMMON_AREA_COMMAND_NONE;\r
-           flash_mode(1);\r
-    } else if(BUTTON_PRESS()) {\r
-           flash_mode(0);\r
-    } else {\r
-           // jump to Flash address of the osimage entry point (LSBit set for thumb mode)\r
-           asm("bx %0\n" : : "r" ( ((int)&_osimage_entry) | 0x1 ) );\r
-    }\r
-}\r
+                 */
+                if( (bootrom_unlocked || ((cmd_start >= prot_end) || (cmd_end < prot_start)))
+                    && (cmd_start >= allow_start) && (cmd_end <= allow_end) ) {
+                    start_addr = cmd_start;
+                    end_addr = cmd_end;
+                } else {
+                    start_addr = end_addr = 0;
+                    dont_ack = 1;
+                    c->cmd = CMD_NACK;
+                    UsbSendPacket(packet, len);
+                }
+            }
+            break;
+
+        default:
+            Fatal();
+            break;
+    }
+
+    if(!dont_ack) {
+        c->cmd = CMD_ACK;
+        UsbSendPacket(packet, len);
+    }
+}
+
+static void flash_mode(int externally_entered)
+{
+       start_addr = 0;
+       end_addr = 0;
+       bootrom_unlocked = 0;
+
+       UsbStart();
+       for(;;) {
+               WDT_HIT();
+
+               UsbPoll(TRUE);
+
+               if(!externally_entered && !BUTTON_PRESS()) {
+                       /* Perform a reset to leave flash mode */
+                       USB_D_PLUS_PULLUP_OFF();
+                       LED_B_ON();
+                       AT91C_BASE_RSTC->RSTC_RCR = RST_CONTROL_KEY | AT91C_RSTC_PROCRST;
+                       for(;;);
+               }
+               if(externally_entered && BUTTON_PRESS()) {
+                       /* Let the user's button press override the automatic leave */
+                       externally_entered = 0;
+               }
+       }
+}
+
+extern char _osimage_entry;
+void BootROM(void)
+{
+    //------------
+    // First set up all the I/O pins; GPIOs configured directly, other ones
+    // just need to be assigned to the appropriate peripheral.
+
+    // Kill all the pullups, especially the one on USB D+; leave them for
+    // the unused pins, though.
+    AT91C_BASE_PIOA->PIO_PPUDR =
+       GPIO_USB_PU                     |
+               GPIO_LED_A                      |
+               GPIO_LED_B                      |
+               GPIO_LED_C                      |
+               GPIO_LED_D                      |
+               GPIO_FPGA_DIN           |
+               GPIO_FPGA_DOUT          |
+               GPIO_FPGA_CCLK          |
+               GPIO_FPGA_NINIT         |
+               GPIO_FPGA_NPROGRAM      |
+               GPIO_FPGA_DONE          |
+               GPIO_MUXSEL_HIPKD       |
+               GPIO_MUXSEL_HIRAW       |
+               GPIO_MUXSEL_LOPKD       |
+               GPIO_MUXSEL_LORAW       |
+               GPIO_RELAY                      |
+               GPIO_NVDD_ON;
+               // (and add GPIO_FPGA_ON)
+       // These pins are outputs
+    AT91C_BASE_PIOA->PIO_OER =
+       GPIO_LED_A                      |
+               GPIO_LED_B                      |
+               GPIO_LED_C                      |
+               GPIO_LED_D                      |
+               GPIO_RELAY                      |
+               GPIO_NVDD_ON;
+       // PIO controls the following pins
+    AT91C_BASE_PIOA->PIO_PER =
+       GPIO_USB_PU                     |
+               GPIO_LED_A                      |
+               GPIO_LED_B                      |
+               GPIO_LED_C                      |
+               GPIO_LED_D;
+
+    USB_D_PLUS_PULLUP_OFF();
+    LED_D_OFF();
+    LED_C_ON();
+    LED_B_OFF();
+    LED_A_OFF();
+
+       AT91C_BASE_EFC0->EFC_FMR =
+               AT91C_MC_FWS_1FWS |
+               MC_FLASH_MODE_MASTER_CLK_IN_MHZ(48);
+
+    // Initialize all system clocks
+    ConfigClocks();
+
+    LED_A_ON();
+
+    int common_area_present = 0;
+    switch(AT91C_BASE_RSTC->RSTC_RSR & AT91C_RSTC_RSTTYP) {
+    case AT91C_RSTC_RSTTYP_WATCHDOG:
+    case AT91C_RSTC_RSTTYP_SOFTWARE:
+    case AT91C_RSTC_RSTTYP_USER:
+           /* In these cases the common_area in RAM should be ok, retain it if it's there */
+           if(common_area.magic == COMMON_AREA_MAGIC && common_area.version == 1) {
+                   common_area_present = 1;
+           }
+           break;
+    default: /* Otherwise, initialize it from scratch */
+           break;
+    }
+
+    if(!common_area_present){
+           /* Common area not ok, initialize it */
+           int i; for(i=0; i<sizeof(common_area); i++) { /* Makeshift memset, no need to drag util.c into this */
+                   ((char*)&common_area)[i] = 0;
+           }
+           common_area.magic = COMMON_AREA_MAGIC;
+           common_area.version = 1;
+           common_area.flags.bootrom_present = 1;
+    }
+
+    common_area.flags.bootrom_present = 1;
+    if(common_area.command == COMMON_AREA_COMMAND_ENTER_FLASH_MODE) {
+           common_area.command = COMMON_AREA_COMMAND_NONE;
+           flash_mode(1);
+    } else if(BUTTON_PRESS()) {
+           flash_mode(0);
+    } else if(*(uint32_t*)&_osimage_entry == 0xffffffffU) {
+           flash_mode(1);
+    } else {
+           // jump to Flash address of the osimage entry point (LSBit set for thumb mode)
+           __asm("bx %0\n" : : "r" ( ((int)&_osimage_entry) | 0x1 ) );
+    }
+}
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