os-workshop

commit 8fb61c246547b061114c2ad9a397f81c25748be1
parent 7f131a68cdeb3babc153df74f5950506c15e07a7
Author: Brian Swetland <swetland@frotz.net>
Date:   Wed,  4 May 2022 16:57:01 -0700

hw: update linker scripts and glue code to use new hw defs

Diffstat:
M
hw/bios.ld
 | 
2
+-
M
hw/simple.ld
 | 
2
+-
M
hw/src/debug.c
 | 
12
++++++++----
M
hw/src/start.S
 | 
4
+++-

4 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/hw/bios.ld b/hw/bios.ld
@@ -3,7 +3,7 @@ ENTRY(_start)
 
 SECTIONS
 {
-  . = 0x80000000;
+  . = 0x40000000;
   .start  : { *(.start) }
   .text   : { *(.text*) }
   .rodata : { *(.rodata*) }
diff --git a/hw/simple.ld b/hw/simple.ld
@@ -3,7 +3,7 @@ ENTRY(_start)
 
 SECTIONS
 {
-  . = 0x80004000;
+  . = 0x40008000;
   .start  : { *(.start) }
   .text   : { *(.text*) }
   .rodata : { *(.rodata*) }
diff --git a/hw/src/debug.c b/hw/src/debug.c
@@ -4,15 +4,19 @@
 #include <stdio.h>
 #include <stdarg.h>
 
-#define UART_BASE 0x10000000
+#include <hw/platform.h>
+#include <hw/litex.h>
 
-#define wr8(v,a) (*((volatile unsigned char*) (a)) = v)
+#define uart_rd(a) io_rd32(UART0_BASE + LX_UART_ ## a)
+#define uart_wr(a,v) io_wr32(UART0_BASE + LX_UART_ ## a, v)
 
 void xputc(unsigned c) {
 	if (c == '\n') {
-		wr8('\r', UART_BASE);
+		while (uart_rd(TXFULL)) ;
+		uart_wr(TX, '\r');
 	}
-	wr8(c, UART_BASE);
+	while (uart_rd(TXFULL)) ;
+	uart_wr(TX, c);
 }
 
 void xputs(const char* s) {
diff --git a/hw/src/start.S b/hw/src/start.S
@@ -1,9 +1,11 @@
 // Copyright 2022, Brian Swetland <swetland@frotz.net>
 // Licensed under the Apache License, Version 2.0
 
+#include <hw/platform.h>
+
 .globl _start
 _start:
-	li sp, 0x81000000
+	li sp, (DRAM_BASE + DRAM_SIZE)
 	jal start
 
 .globl exit