Rename MCU

stm32f103t8u6-bootloader/src/usb_com.c

@@ -0,0 +1,189 @@
+#include "usb_com.h"
+#include "usb_util.h"
+#include "commands.h"
+#include "buildinfo.h"
+#include "flash.h"
+
+static const BootloaderInfo_t BootloaderInfo =
+{
+    .build_date = BUILD_DATE,
+    .build_number = BUILD_NUMBER,
+    .flash_application_start = FLASH_APPLICATION_BASE,
+    .flash_application_size = (FLASH_PAGES - FLASH_BOOTLOADER_PAGES)
+        * FLASH_PAGE_BYTES,
+    .version_major = BUILD_VERSION_MAJOR,
+    .version_minor = BUILD_VERSION_MINOR,
+    .version_patch = BUILD_VERSION_PATCH,
+    .identifier = "STM32F103T8U6"
+};
+
+
+static Command_t USB_PendingCommand = CMD_NOP;
+
+static void USB_EP1Transmit(const void *data, uint16_t length)
+{
+    USB_MemoryToPMA(USB_BTABLE_ENTRIES[1].ADDR_TX, data, length);
+    USB_BTABLE_ENTRIES[1].COUNT_TX = length;
+
+    // Assume that STAT_TX is currently NAK (which is the case after a reset or
+    // after a correct transfer, just not if the function is called multiple
+    // times without an actual transfer in between)
+    USB->EP1R = (USB_EP_TX_NAK ^ USB_EP_TX_VALID)
+        | USB_EP_CTR_RX | USB_EP_CTR_TX | USB_EPR_EP_TYPE_BULK | 1;
+}
+
+bool USB_HandleCommand(const USB_SetupPacket_t *sp)
+{
+    // The command is stored in the second byte (bRequest field) of the setup
+    // packet
+    Command_t command = sp->bRequest;
+
+    const void *reply_data = NULL;
+    int reply_length = 0;
+
+    switch(command)
+    {
+        case CMD_BOOTLOADER_INFO:
+            reply_data = &BootloaderInfo;
+            reply_length = sizeof(BootloaderInfo)
+                + strlen(BootloaderInfo.identifier);
+            break;
+
+        case CMD_READ_CRC:
+            // The command will be executed as soon as the start address and
+            // length are transferred via EP2
+            USB_PendingCommand = CMD_READ_CRC;
+            break;
+
+        case CMD_READ_MEMORY:
+            // The command will be executed as soon as the start address and
+            // length are transferred via EP2
+            USB_PendingCommand = CMD_READ_MEMORY;
+            break;
+
+        case CMD_ERASE_PAGE:
+            // The command will be executed as soon as the page number is
+            // transferred via EP2. Since only a single byte is needed for the
+            // page index, this would also be technically be possible with just
+            // one setup packet. Since this is the only command, this minor
+            // USB bandwith saving is not worth the extra special case.
+            USB_PendingCommand = CMD_ERASE_PAGE;
+            break;
+
+        case CMD_PROGRAM:
+            USB_PendingCommand = CMD_PROGRAM;
+            break;
+
+        case CMD_EXIT:
+            return false;
+
+        default:
+            // Invalid commands get ignored
+            break;
+    }
+
+    if(reply_length > 0)
+    {
+        USB_EP1Transmit(reply_data, reply_length);
+    }
+
+    return true;
+}
+
+void USB_HandleEP2Out(void)
+{
+    // Read how many bytes have been received by EP2
+    int packet_length = USB_BTABLE_ENTRIES[2].COUNT_RX & 0x3ff;
+
+    // The meaning of the received data depends on the command transmitted via
+    // a setup packet before it
+    switch(USB_PendingCommand)
+    {
+        case CMD_READ_CRC:
+            if(packet_length == 8)
+            {
+                uint32_t buff[2];
+                USB_PMAToMemory(buff, USB_BTABLE_ENTRIES[2].ADDR_RX,
+                    sizeof(buff));
+                uint32_t *addr = (uint32_t*)(buff[0]);
+                uint32_t length = buff[1];
+
+                CRC->CR = CRC_CR_RESET;
+
+                // TODO: Add basic sanity checks so it isn't possible to crash
+                // the bootloader with this command (or at least not as easy)
+                while(length > 4)
+                {
+                    CRC->DR = *addr++;
+                    length -= 4;
+                }
+                CRC->DR = *addr & (0xffffffffU >> (32 - 8 * length));
+
+                buff[0] = CRC->DR;
+                USB_EP1Transmit(buff, 4);
+            }
+            break;
+
+        case CMD_READ_MEMORY:
+            if(packet_length == 8)
+            {
+                uint32_t buff[2];
+                USB_PMAToMemory(buff, USB_BTABLE_ENTRIES[2].ADDR_RX,
+                    sizeof(buff));
+                uint8_t *start = (uint8_t*)(buff[0]);
+                uint32_t length = buff[1];
+
+                if(length > 64)
+                {
+                    length = 64;
+                }
+
+                USB_EP1Transmit(start, length);
+            }
+            break;
+
+        case CMD_ERASE_PAGE:
+            if(packet_length == 1)
+            {
+                // Not that only one byte has been received but since the PMA
+                // can only be accessed word-wise, we'll have to copy two
+                uint8_t buff[2];
+                USB_PMAToMemory(buff, USB_BTABLE_ENTRIES[2].ADDR_RX,
+                    sizeof(buff));
+
+                unsigned int page_index = buff[0];
+                if(page_index < FLASH_BOOTLOADER_PAGES)
+                {
+                    // Do not allow erasing the bootloader
+                    buff[0] = FLASH_PROHIBITED;
+                }
+                else
+                {
+                    buff[0] = Flash_ErasePage(page_index);
+                }
+
+                // Reply with status byte
+                USB_EP1Transmit(buff, 1);
+            }
+            break;
+
+        case CMD_PROGRAM:;
+            uint32_t start;
+            USB_PMAToMemory(&start, USB_BTABLE_ENTRIES[2].ADDR_RX, 4);
+            uint32_t length = packet_length - 4;
+            if(start >= FLASH_APPLICATION_BASE && start + length
+                <= FLASH_BASE + FLASH_PAGE_BYTES * FLASH_PAGES)
+            {
+                // Program directly from PMA without an intermediate buffer in
+                // RAM
+                Flash_ProgramFromPMA(start, USB_BTABLE_ENTRIES[2].ADDR_RX + 4,
+                    length);
+            }
+            break;
+
+        default:
+            break;
+    }
+
+    USB_PendingCommand = CMD_NOP;
+}