From 1ce194007b684086dcf6af000fce946e36ffc445 Mon Sep 17 00:00:00 2001
From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Fri, 8 Jan 2021 19:18:44 +0100
Subject: [PATCH] software: allow BIOS compilation with UART disabled.

---
 litex/soc/software/bios/boot.c          |  4 ++++
 litex/soc/software/bios/cmds/cmd_boot.c |  2 ++
 litex/soc/software/bios/isr.c           |  2 ++
 litex/soc/software/bios/main.c          | 22 +++++++++++---------
 litex/soc/software/libbase/console.c    | 27 +++++++++++++++++++++++++
 litex/soc/software/libbase/uart.c       |  4 ++++
 6 files changed, 52 insertions(+), 9 deletions(-)

diff --git a/litex/soc/software/bios/boot.c b/litex/soc/software/bios/boot.c
index 64e0ffae5..ed2174f44 100644
--- a/litex/soc/software/bios/boot.c
+++ b/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                                                         */
 /*-----------------------------------------------------------------------*/
diff --git a/litex/soc/software/bios/cmds/cmd_boot.c b/litex/soc/software/bios/cmds/cmd_boot.c
index e46e8e97b..24743bf15 100644
--- a/litex/soc/software/bios/cmds/cmd_boot.c
+++ b/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"
diff --git a/litex/soc/software/bios/isr.c b/litex/soc/software/bios/isr.c
index e7bf91afc..a7fe63aee 100644
--- a/litex/soc/software/bios/isr.c
+++ b/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
 
diff --git a/litex/soc/software/bios/main.c b/litex/soc/software/bios/main.c
index 0ffb03bdf..86a797fef 100644
--- a/litex/soc/software/bios/main.c
+++ b/litex/soc/software/bios/main.c
@@ -49,27 +49,29 @@
 
 static void boot_sequence(void)
 {
-	if(serialboot()) {
+#ifdef CSR_UART_BASE
+	if (serialboot() == 0)
+		return;
+#endif
 #ifdef FLASH_BOOT_ADDRESS
-		flashboot();
+	flashboot();
 #endif
 #ifdef ROM_BOOT_ADDRESS
-		romboot();
+	romboot();
 #endif
 #if defined(CSR_SPISDCARD_BASE) || defined(CSR_SDCORE_BASE)
-		sdcardboot();
+	sdcardboot();
 #endif
 #if defined(CSR_SATA_SECTOR2MEM_BASE)
-		sataboot();
+	sataboot();
 #endif
 #ifdef CSR_ETHMAC_BASE
 #ifdef CSR_ETHPHY_MODE_DETECTION_MODE_ADDR
-		eth_mode();
+	eth_mode();
 #endif
-		netboot();
+	netboot();
 #endif
-		printf("No boot medium found\n");
-	}
+	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");
diff --git a/litex/soc/software/libbase/console.c b/litex/soc/software/libbase/console.c
index 7861a1d98..ec434643b 100644
--- a/litex/soc/software/libbase/console.c
+++ b/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) {
diff --git a/litex/soc/software/libbase/uart.c b/litex/soc/software/libbase/uart.c
index 81aa128b4..0f4b76c82 100644
--- a/litex/soc/software/libbase/uart.c
+++ b/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.
@@ -150,4 +152,6 @@ void uart_sync(void)
 	while (uart_txfull_read());
 }
 
+#endif
+
 #endif
\ No newline at end of file