fix: works?

main.c

@@ -10,113 +10,132 @@
 #include "netif/ethernet.h"
 #include "systick.h"
 
-#define LED1_PIN 0
-#define LED2_PIN 2
+#define LED1_PIN 0  // PA0
+#define LED2_PIN 2  // PA2
+
+#define HSE_STARTUP_TIMEOUT 10000
+#define PLL_LOCK_TIMEOUT 10000
+#define LED_TOGGLE_INTERVAL_MS 500
+#define LINK_POLL_INTERVAL_MS 500
 
 #define RCC_PREDIV1_OFFSET 0
+#define HSE_CLOCK_MHZ 32
+#define PREDIV1_DIVISOR 4
+#define PLL_MULTIPLIER 15
 
 struct netif g_netif;
 
-void init_leds() {
-  RCC->APB2PCENR |= RCC_APB2Periph_GPIOA;
-  GPIOA->CFGLR &= ~((0xf << (4 * 0)) | (0xf << (4 * 2)));
-  GPIOA->CFGLR |= (GPIO_Speed_10MHz | GPIO_CNF_OUT_PP) << (4 * 0);
-  GPIOA->CFGLR |= (GPIO_Speed_10MHz | GPIO_CNF_OUT_PP) << (4 * 2);
-}
+int clock_init(void);
+void led_init(void);
+void lwip_stack_init(void);
 
-int main() {
-  SystemInit();
-
-  // 1. HSE (32MHz)
-  // 2. PREDIV1 / 4.
-  // 3. PLL source = HSE, PLL x15.
-  // 4. (32MHz / 4) * 15 = 120MHz SYSCLK
-
-  RCC->INTR = 0x009F0000;
+int clock_init(void) {
+  RCC->INTR = 0x009f0000;
   RCC->CTLR &= ~(RCC_HSE_ON | RCC_PLLON);
   RCC->CFGR0 = 0x00000000;
-  RCC->CTLR |= RCC_HSE_ON;
 
-  int timeout;
-  for (timeout = 10000; timeout > 0; timeout--) {
-    if (RCC->CTLR & RCC_HSERDY) break;  // wait for HSE
-  }
-  if (timeout == 0) {
-    printf("Error: HSE failed to start\n");
-    return -1;
+  RCC->CTLR |= RCC_HSE_ON;
+  for (int timeout = HSE_STARTUP_TIMEOUT; timeout > 0; timeout--) {
+    if (RCC->CTLR & RCC_HSERDY) break;
+    if (timeout == 1) {
+      printf("Error: HSE failed to start\n");
+      return -1;
+    }
   }
 
   RCC->CFGR0 |= (uint32_t)RCC_PPRE1_DIV2;
-  RCC->CFGR2 = ((3) << 0);  // PREDIV1 divisor = 3+1 = 4
+  RCC->CFGR2 = (PREDIV1_DIVISOR - 1);
   RCC->CFGR0 |= RCC_PLLSource_HSE_Div1 | RCC_PLLMul_15;
 
   RCC->CTLR |= RCC_PLLON;
-  printf("Main PLL enabled. Waiting for lock...\n");
-  for (timeout = 10000; timeout > 0; timeout--) {
+  printf("Main PLL en. Waiting for lock...\n");
+  for (int timeout = PLL_LOCK_TIMEOUT; timeout > 0; timeout--) {
     if (RCC->CTLR & RCC_PLLRDY) break;
-  }
-  if (timeout == 0) {
-    printf("error: main pll lock failed\n");
-    return -1;
+    if (timeout == 1) {
+      printf("Error: Main PLL lock failed\n");
+      return -1;
+    }
   }
   printf("Main PLL Locked\n");
 
   RCC->CFGR0 = (RCC->CFGR0 & ~RCC_SW) | RCC_SW_PLL;
-
   while ((RCC->CFGR0 & RCC_SWS) != RCC_SWS_PLL);
 
-  printf("SysClock set to 120MHz\n");
+  printf("System clock set to %dMHz.\n",
+         (HSE_CLOCK_MHZ / PREDIV1_DIVISOR) * PLL_MULTIPLIER);
+  return 0;
+}
 
-  systick_init();
-  init_leds();
+void led_init(void) {
+  RCC->APB2PCENR |= RCC_APB2Periph_GPIOA;
+  GPIOA->CFGLR &= ~((0xf << (4 * LED1_PIN)) | (0xf << (4 * LED2_PIN)));
+  GPIOA->CFGLR |= (GPIO_Speed_10MHz | GPIO_CNF_OUT_PP) << (4 * LED1_PIN);
+  GPIOA->CFGLR |= (GPIO_Speed_10MHz | GPIO_CNF_OUT_PP) << (4 * LED2_PIN);
+}
+
+void lwip_stack_init(void) {
+  ip_addr_t ipaddr, netmask, gw;
 
   lwip_init();
 
-  ip_addr_t ipaddr, netmask, gw;
   IP4_ADDR(&ipaddr, 0, 0, 0, 0);
   IP4_ADDR(&netmask, 0, 0, 0, 0);
   IP4_ADDR(&gw, 0, 0, 0, 0);
 
   netif_add(&g_netif, &ipaddr, &netmask, &gw, NULL, &ethernetif_init,
             &ethernet_input);
-  //   netif_set_link_callback(&g_netif, link_status_callback);
+
   netif_set_default(&g_netif);
   netif_set_up(&g_netif);
 
+  printf("Starting DHCP client...\n");
   dhcp_start(&g_netif);
+}
 
-  uint32_t last_led_toggle = 0;
-  uint32_t last_send_time = 0;
+int main() {
+  SystemInit();
+
+  if (clock_init() != 0) {
+    // eating dirt?
+    while (1);
+  }
+
+  systick_init();
+  led_init();
+  lwip_stack_init();
+
+  uint32_t last_led_toggle_time = 0;
+  uint32_t last_link_poll_time = 0;
   int led_state = 0;
+  int ip_address_printed = 0;
 
   while (1) {
-    ethernetif_link_poll(&g_netif);
+    ethernetif_input(&g_netif);
 
-    if (netif_is_link_up(&g_netif)) {
-      ethernetif_input(&g_netif);
+    if (millis() - last_link_poll_time > LINK_POLL_INTERVAL_MS) {
+      ethernetif_link_poll(&g_netif);
+      last_link_poll_time = millis();
     }
 
     sys_check_timeouts();
 
-    // run_tx_test();
-
     uint32_t now = millis();
-
-    if (now - last_led_toggle > 500) {
+    if (now - last_led_toggle_time > LED_TOGGLE_INTERVAL_MS) {
       if (led_state) {
-        GPIOA->BSHR = (1 << 0);
+        GPIOA->BSHR = (1 << LED1_PIN);
       } else {
-        GPIOA->BSHR = (1 << (0 + 16));
+        GPIOA->BSHR = (1 << (LED1_PIN + 16));
       }
       led_state = !led_state;
-      last_led_toggle = now;
+      last_led_toggle_time = now;
     }
 
-    static int ip_printed = 0;
-    if (g_netif.ip_addr.addr != 0 && !ip_printed) {
+    if (!ip_address_printed && g_netif.ip_addr.addr != 0) {
       printf("IP address assigned: %s\n",
              ip4addr_ntoa(netif_ip4_addr(&g_netif)));
-      ip_printed = 1;
+      ip_address_printed = 1;
+
+      GPIOA->BSHR = (1 << LED2_PIN);
     }
   }
 }