Merge branch 'master' of https://github.com/LabNelson/rpi4-osdev

README.md

@@ -4,7 +4,7 @@ Writing a "bare metal" operating system for Raspberry Pi 4
 Introduction
 ------------
 
-As a tech CEO @RealVNC, I don't write code any more. And I've recently realised just how much I miss it.
+As a tech CEO, I don't write code any more. And I've recently realised just how much I miss it.
 
 Currently in the throes of a nationwide "lockdown" due to Covid-19 (and having been spared my usual commute), I've found myself with more hours in the day. I have taken this time for myself and used it to fulfil a childhood ambition - to write a **bare metal** operating system that runs on commercial hardware.
 

part10-multicore/io.c

@@ -19,8 +19,8 @@ enum {
 
 enum {
     Pull_None = 0,
-    Pull_Down = 1, // Are down and up the right way around?
-    Pull_Up = 2
+    Pull_Down = 2,
+    Pull_Up = 1
 };
 
 void mmio_write(long reg, unsigned int val) { *(volatile unsigned int *)reg = val; }

part11-breakout-smp/Makefile.gcc

@@ -1,9 +1,8 @@
 CFILES = $(wildcard *.c lib/*.c)
 OFILES = $(CFILES:.c=.o)
-GCCFLAGS = -Wall -O2 -ffreestanding -nostdinc -nostdlib
+GCCFLAGS = -Wall -O2 -ffreestanding -nostdinc -nostdlib -nostartfiles
 GCCPATH = ../../gcc-arm-10.3-2021.07-x86_64-aarch64-none-elf/bin
 
-
 all: clean kernel8.img
 
 boot/boot.o: boot/boot.S

part11-breakout-smp/lib/io.c

@@ -19,8 +19,8 @@ enum {
 
 enum {
     Pull_None = 0,
-    Pull_Down = 1, // Are down and up the right way around?
-    Pull_Up = 2
+    Pull_Down = 2,
+    Pull_Up = 1
 };
 
 void mmio_write(long reg, unsigned int val) { *(volatile unsigned int *)reg = val; }

part12-wgt/lib/io.c

@@ -19,8 +19,8 @@ enum {
 
 enum {
     Pull_None = 0,
-    Pull_Down = 1, // Are down and up the right way around?
-    Pull_Up = 2
+    Pull_Down = 2,
+    Pull_Up = 1
 };
 
 void mmio_write(long reg, unsigned int val) { *(volatile unsigned int *)reg = val; }

part13-interrupts/lib/io.c

@@ -19,8 +19,8 @@ enum {
 
 enum {
     Pull_None = 0,
-    Pull_Down = 1, // Are down and up the right way around?
-    Pull_Up = 2
+    Pull_Down = 2,
+    Pull_Up = 1
 };
 
 void mmio_write(long reg, unsigned int val) { *(volatile unsigned int *)reg = val; }

part14-spi-ethernet/lib/io.c

@@ -19,8 +19,8 @@ enum {
 
 enum {
     Pull_None = 0,
-    Pull_Down = 1, // Are down and up the right way around?
-    Pull_Up = 2
+    Pull_Down = 2,
+    Pull_Up = 1
 };
 
 void mmio_write(long reg, unsigned int val) { *(volatile unsigned int *)reg = val; }

part4-miniuart/io.c

@@ -17,8 +17,8 @@ enum {
 
 enum {
     Pull_None = 0,
-    Pull_Down = 1, // Are down and up the right way around?
-    Pull_Up = 2
+    Pull_Down = 2,
+    Pull_Up = 1
 };
 
 void mmio_write(long reg, unsigned int val) { *(volatile unsigned int *)reg = val; }

part5-framebuffer/io.c

@@ -18,8 +18,8 @@ enum {
 
 enum {
     Pull_None = 0,
-    Pull_Down = 1, // Are down and up the right way around?
-    Pull_Up = 2
+    Pull_Down = 2,
+    Pull_Up = 1
 };
 
 void mmio_write(long reg, unsigned int val) { *(volatile unsigned int *)reg = val; }

part6-breakout/io.c

@@ -18,8 +18,8 @@ enum {
 
 enum {
     Pull_None = 0,
-    Pull_Down = 1, // Are down and up the right way around?
-    Pull_Up = 2
+    Pull_Down = 2,
+    Pull_Up = 1
 };
 
 void mmio_write(long reg, unsigned int val) { *(volatile unsigned int *)reg = val; }

part7-bluetooth/io.c

@@ -18,8 +18,8 @@ enum {
 
 enum {
     Pull_None = 0,
-    Pull_Down = 1, // Are down and up the right way around?
-    Pull_Up = 2
+    Pull_Down = 2,
+    Pull_Up = 1
 };
 
 void mmio_write(long reg, unsigned int val) { *(volatile unsigned int *)reg = val; }

part8-breakout-ble/io.c

@@ -18,8 +18,8 @@ enum {
 
 enum {
     Pull_None = 0,
-    Pull_Down = 1, // Are down and up the right way around?
-    Pull_Up = 2
+    Pull_Down = 2,
+    Pull_Up = 1
 };
 
 void mmio_write(long reg, unsigned int val) { *(volatile unsigned int *)reg = val; }

part9-sound/io.c

@@ -19,8 +19,8 @@ enum {
 
 enum {
     Pull_None = 0,
-    Pull_Down = 1, // Are down and up the right way around?
-    Pull_Up = 2
+    Pull_Down = 2,
+    Pull_Up = 1
 };
 
 void mmio_write(long reg, unsigned int val) { *(volatile unsigned int *)reg = val; }