software: allow BIOS compilation with UART disabled.

litex/soc/software/bios/boot.c

@@ -100,6 +100,8 @@ void romboot(void)
 /* Serial Boot                                                           */
 /*-----------------------------------------------------------------------*/
 
+#ifdef CSR_UART_BASE
+
 static int check_ack(void)
 {
 	int recognized;
@@ -265,6 +267,8 @@ int serialboot(void)
 	return 1;
 }
 
+#endif
+
 /*-----------------------------------------------------------------------*/
 /* Ethernet Boot                                                         */
 /*-----------------------------------------------------------------------*/

litex/soc/software/bios/cmds/cmd_boot.c

@@ -50,7 +50,9 @@ define_command(romboot, romboot, "Boot from ROM", BOOT_CMDS);
  * Boot software from serial interface
  *
  */
+#ifdef CSR_UART_BASE
 define_command(serialboot, serialboot, "Boot from Serial (SFL)", BOOT_CMDS);
+#endif
 
 /**
  * Command "netboot"

litex/soc/software/bios/isr.c

@@ -151,10 +151,12 @@ void isr(void)
 
 	irqs = irq_pending() & irq_getmask();
 
+#ifdef CSR_UART_BASE
 #ifndef UART_POLLING
 	if(irqs & (1 << UART_INTERRUPT))
 		uart_isr();
 #endif
+#endif
 }
 #endif
 

litex/soc/software/bios/main.c

@@ -49,7 +49,10 @@
 
 static void boot_sequence(void)
 {
-	if(serialboot()) {
+#ifdef CSR_UART_BASE
+	if (serialboot() == 0)
+		return;
+#endif
 #ifdef FLASH_BOOT_ADDRESS
 	flashboot();
 #endif
@@ -70,7 +73,6 @@ static void boot_sequence(void)
 #endif
 	printf("No boot medium found\n");
 }
-}
 
 int main(int i, char **c)
 {
@@ -85,7 +87,9 @@ int main(int i, char **c)
 	irq_setmask(0);
 	irq_setie(1);
 #endif
+#ifdef CSR_UART_BASE
 	uart_init();
+#endif
 
 	printf("\n");
 	printf("\e[1m        __   _ __      _  __\e[0m\n");

litex/soc/software/libbase/console.c

@@ -3,6 +3,8 @@
 #include <stdio.h>
 #include <stdarg.h>
 
+#include <generated/csr.h>
+
 FILE *stdin, *stdout, *stderr;
 
 static console_write_hook write_hook;
@@ -20,6 +22,7 @@ void console_set_read_hook(console_read_hook r, console_read_nonblock_hook rn)
 	read_nonblock_hook = rn;
 }
 
+#ifdef CSR_UART_BASE
 int putchar(int c)
 {
 	uart_write(c);
@@ -46,6 +49,30 @@ int readchar_nonblock(void)
 		|| ((read_nonblock_hook != NULL) && read_nonblock_hook()));
 }
 
+#else
+
+int putchar(int c)
+{
+	if(write_hook != NULL)
+		write_hook(c);
+	return c;
+}
+
+char readchar(void)
+{
+	while(1) {
+		if((read_nonblock_hook != NULL) && read_nonblock_hook())
+			return read_hook();
+	}
+}
+
+int readchar_nonblock(void)
+{
+	return ((read_nonblock_hook != NULL) && read_nonblock_hook());
+}
+
+#endif
+
 int puts(const char *s)
 {
 	while(*s) {

litex/soc/software/libbase/uart.c

@@ -2,6 +2,8 @@
 #include <irq.h>
 #include <generated/csr.h>
 
+#ifdef CSR_UART_BASE
+
 /*
  * Buffer sizes must be a power of 2 so that modulos can be computed
  * with logical AND.
@@ -151,3 +153,5 @@ void uart_sync(void)
 }
 
 #endif
+
+#endif