fix: idk

inc/hw_i2c.h

@@ -150,10 +150,11 @@ static inline void i2c_init(void) {
   RCC->APB2PCENR |= RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO;
   RCC->APB1PCENR |= RCC_APB1Periph_I2C1;
 
-  // PB6 (SCL) and PB7 (SDA)
+  AFIO->PCFR1 |= AFIO_PCFR1_I2C1_REMAP;  // I2C1_RM: 1
-  GPIOB->CFGLR &= ~(0xFF << (4 * 6));
+
-  GPIOB->CFGLR |= ((GPIO_Speed_10MHz | GPIO_CNF_OUT_OD_AF) << (4 * 6)) |
+  // PB8 (SCL) and PB9 (SDA)
-                  ((GPIO_Speed_10MHz | GPIO_CNF_OUT_OD_AF) << (4 * 7));
+  funPinMode(PB8, GPIO_CFGLR_OUT_10Mhz_AF_OD);
+  funPinMode(PB9, GPIO_CFGLR_OUT_10Mhz_AF_OD);
 
   // Reset I2C1 to init all regs
   RCC->APB1PRSTR |= RCC_APB1Periph_I2C1;

port/ethernetif.c

@@ -70,6 +70,15 @@ err_t ethernetif_init(struct netif* netif) {
 static err_t low_level_output(struct netif* netif, struct pbuf* p) {
   (void)netif;
 
+  // single-segment pbuf
+  if (p->next == NULL && p->len <= ETH_TX_BUF_SIZE) {
+    if (eth_send_packet(p->payload, p->len) == 0) {
+      LINK_STATS_INC(link.xmit);
+      return ERR_OK;
+    }
+  }
+
+  // chain of pbufs
   static uint8_t tx_buffer[ETH_TX_BUF_SIZE];
   uint32_t total_len = 0;
 
@@ -82,21 +91,13 @@ static err_t low_level_output(struct netif* netif, struct pbuf* p) {
     total_len += q->len;
   }
 
-  // send packet via driver
+  if (eth_send_packet(tx_buffer, total_len) == 0) {
-  int result = eth_send_packet(tx_buffer, total_len);
-
-  if (result == -1) {
-    // tx queue full
-    LINK_STATS_INC(link.drop);
-    return ERR_BUF;
-  } else if (result == -2) {
-    // invalid length
-    LINK_STATS_INC(link.err);
-    return ERR_ARG;
-  }
-
     LINK_STATS_INC(link.xmit);
     return ERR_OK;
+  }
+
+  LINK_STATS_INC(link.drop);
+  return ERR_BUF;
 }
 
 void ethernetif_input(struct netif* netif) {
@@ -108,13 +109,8 @@ void ethernetif_input(struct netif* netif) {
     struct pbuf* p = pbuf_alloc(PBUF_RAW, length, PBUF_POOL);
 
     if (p != NULL) {
-      // copy packet into pbuf chain
+      // usually contiguous in PBUF_POOL
-      uint32_t offset = 0;
+      pbuf_take(p, packet, length);
-      for (struct pbuf* q = p; q != NULL; q = q->next) {
-        memcpy(q->payload, packet + offset, q->len);
-        offset += q->len;
-      }
-
       LINK_STATS_INC(link.recv);
 
       // pass to lwIP

port/lwipopts.h

@@ -11,7 +11,7 @@
 // #define ETHARP_DEBUG LWIP_DBG_ON
 
 #define NO_SYS 1
-#define SYS_LIGHTWEIGHT_PROT 1
+#define SYS_LIGHTWEIGHT_PROT 0
 #define LWIP_NETCONN 0
 #define LWIP_SOCKET 0