Slow down flash access during eboot firmware copy on XMC chips

Part 2 - Identify the chip type. Note: there may still be issues with the access speed change. This is very much experimental.

bootloaders/eboot/eboot.c

@@ -124,7 +124,28 @@ int copy_raw(const uint32_t src_addr,
  return 0;
 }
 
+#define XMC_SUPPORT
+#ifdef XMC_SUPPORT
+// Define a few SPI0 registers we need access to
+#define ESP8266_REG(addr) *((volatile uint32_t *)(0x60000000+(addr)))
+#define SPI0CMD ESP8266_REG(0x200)
+#define SPI0CLK ESP8266_REG(0x218)
+#define SPI0C ESP8266_REG(0x208)
+#define SPI0W0 ESP8266_REG(0x240)
 
+#define SPICMDRDID (1 << 28)
+
+/* spi_flash_get_id()
+ Returns the flash chip ID - same as the SDK function.
+ We need our own version as the SDK isn't available here.
+ */
+uint32_t __attribute__((noinline)) spi_flash_get_id() {
+ SPI0W0=0;
+ SPI0CMD=SPICMDRDID;
+ while (SPI0CMD) {}
+ return SPI0W0;
+}
+#endif // XMC_SUPPORT
 
 void main()
 {
@@ -148,15 +169,12 @@ void main()
  if (cmd.action == ACTION_COPY_RAW) {
  ets_putc('c'); ets_putc('p'); ets_putc(':');
 
-#define ESP8266_REG(addr) *((volatile uint32_t *)(0x60000000+(addr)))
-#define SPI0CLK ESP8266_REG(0x218)
-#define SPI0C ESP8266_REG(0x208)
-
+#ifdef XMC_SUPPORT
  // save the flash access speed registers
  uint32_t spi0clk = SPI0CLK;
  uint32_t spi0c = SPI0C;
 
- uint32_t vendor = 0;//spi_flash_get_id() & 0x000000ff;
+ uint32_t vendor = spi_flash_get_id() & 0x000000ff;
  if (vendor == SPI_FLASH_VENDOR_XMC) {
  uint32_t flashinfo=0;
  if (SPIRead(0, &flashinfo, 4)) {
@@ -182,14 +200,16 @@ void main()
  }
  }
  }
+#endif // XMC_SUPPORT
  ets_wdt_disable();
  res = copy_raw(cmd.args[0], cmd.args[1], cmd.args[2]);
  ets_wdt_enable();
 
+#ifdef XMC_SUPPORT
  // restore the saved flash access speed registers
  SPI0CLK = spi0clk;
  SPI0C = spi0c;
-
+#endif 
  ets_putc('0'+res); ets_putc('\n');
  if (res == 0) {
  cmd.action = ACTION_LOAD_APP;