From 9c5e60f6560e909effa2a5d31b3a630c23198aac Mon Sep 17 00:00:00 2001
From: Alexander von Gluck IV <kallisti5@unixzen.com>
Date: Tue, 22 May 2012 07:03:56 -0500
Subject: [PATCH] rPi MMU: Fixes to hrev44189

* I had the wrong addresses, 0x20 was the physical
  address not a mapped one.
* Attempt to map uart in mmu post mmu_init.
---
 headers/private/kernel/arch/arm/bcm2708.h        | 11 +++++------
 src/system/boot/platform/raspberrypi_arm/mmu.cpp | 16 +++++++++-------
 .../boot/platform/raspberrypi_arm/serial.cpp     |  6 +++++-
 src/system/boot/platform/raspberrypi_arm/start.c |  2 +-
 4 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/headers/private/kernel/arch/arm/bcm2708.h b/headers/private/kernel/arch/arm/bcm2708.h
index 010851ccef..740837224b 100644
--- a/headers/private/kernel/arch/arm/bcm2708.h
+++ b/headers/private/kernel/arch/arm/bcm2708.h
@@ -36,10 +36,9 @@
  *  - BCM2835-ARM-Peripherals.pdf
  */
 
-// 1.2.2 notes that peripherals are remapped from 0x7e to 0x20
+// Section 1.2.2
 #define BCM2708_SDRAM_BASE		0x00000000
-#define BCM2708_DEVICEHW_BASE	0x7E000000 // Real Hardware Base
-#define BCM2708_DEVICEFW_BASE	0x20000000 // Firmware Mapped Base
+#define BCM2708_PERIPHERAL_BASE	0x20000000
 
 #define ST_BASE			0x3000
 	// System Timer, sec 12.0, page 172
@@ -77,11 +76,11 @@
 #define ARM_CTRL_0_SBM_BASE		(ARM_BASE + 0x800)
 	// ARM Semaphores, Doorbells, and Mailboxes
 
-#define VECT_BASE 0xffff0000
+#define VECT_BASE 0xFFFF0000
 #define VECT_SIZE SIZE_4K
 
-#define DEVICE_BASE		BCM2708_DEVICEHW_BASE
-#define DEVICE_SIZE		0x1000000
+#define PERIPHERAL_BASE	BCM2708_PERIPHERAL_BASE
+#define PERIPHERAL_SIZE 0xFFFFFF
 
 #define SDRAM_BASE		BCM2708_SDRAM_BASE
 #define SDRAM_SIZE		0x4000000
diff --git a/src/system/boot/platform/raspberrypi_arm/mmu.cpp b/src/system/boot/platform/raspberrypi_arm/mmu.cpp
index e628255c90..f5f0368dda 100644
--- a/src/system/boot/platform/raspberrypi_arm/mmu.cpp
+++ b/src/system/boot/platform/raspberrypi_arm/mmu.cpp
@@ -62,12 +62,16 @@ struct memblock {
 static struct memblock LOADER_MEMORYMAP[] = {
 	{
 		"devices",
-		DEVICE_BASE,
-		DEVICE_BASE + DEVICE_SIZE - 1,
+		PERIPHERAL_BASE,
+		PERIPHERAL_BASE + PERIPHERAL_SIZE,
 		MMU_L2_FLAG_B,
 	},
+	// Device memory between 0x0 and 0x10000000
+	// (0x0) Ram / Video ram (0x10000000) (256MB)
+	// We don't detect the split yet, se we have to be
+	// careful not to run into video ram.
 	{
-		"RAM_loader", // 1MB loader
+		"RAM_loader", // 1MB for the loader
 		SDRAM_BASE + 0,
 		SDRAM_BASE + 0x0fffff,
 		MMU_L2_FLAG_C,
@@ -84,7 +88,6 @@ static struct memblock LOADER_MEMORYMAP[] = {
 		SDRAM_BASE + 0x11FFFFF,
 		MMU_L2_FLAG_C,
 	},
-#if 0
 	{
 		"RAM_stack", // stack
 		SDRAM_BASE + 0x1200000,
@@ -97,7 +100,7 @@ static struct memblock LOADER_MEMORYMAP[] = {
 		SDRAM_BASE + 0x2500000,
 		MMU_L2_FLAG_C,
 	},
-
+	// (0x2500000 ~37MB)
 #ifdef FB_BASE
 	{
 		"framebuffer", // 2MB framebuffer ram
@@ -106,7 +109,6 @@ static struct memblock LOADER_MEMORYMAP[] = {
 		MMU_L2_FLAG_AP_RW|MMU_L2_FLAG_C,
 	},
 #endif
-#endif
 };
 
 
@@ -585,7 +587,7 @@ mmu_init(void)
 {
 	CALLED();
 
-	mmu_write_C1(mmu_read_C1() & ~((1<<29)|(1<<28)|(1<<0)));
+	mmu_write_C1(mmu_read_C1() & ~((1 << 29) | (1 << 28) | (1 << 0)));
 		// access flag disabled, TEX remap disabled, mmu disabled
 
 	uint32 highestRAMAddress = SDRAM_BASE;
diff --git a/src/system/boot/platform/raspberrypi_arm/serial.cpp b/src/system/boot/platform/raspberrypi_arm/serial.cpp
index 3d58f87011..b97d0b7a6a 100644
--- a/src/system/boot/platform/raspberrypi_arm/serial.cpp
+++ b/src/system/boot/platform/raspberrypi_arm/serial.cpp
@@ -14,6 +14,7 @@
 #include <boot/platform.h>
 #include <arch/cpu.h>
 #include <boot/stage2.h>
+#include "mmu.h"
 
 #include <string.h>
 
@@ -87,7 +88,10 @@ serial_cleanup(void)
 extern "C" void
 serial_init(void)
 {
-	gUART = arch_get_uart_pl011(BOARD_UART_DEBUG, BOARD_UART_CLOCK);
+	addr_t uart0 = mmu_map_physical_memory(PERIPHERAL_BASE + BOARD_UART_DEBUG,
+		0x00004000, kDefaultPageFlags);
+
+	gUART = arch_get_uart_pl011(uart0, BOARD_UART_CLOCK);
 	gUART->InitEarly();
 	gUART->InitPort(9600);
 
diff --git a/src/system/boot/platform/raspberrypi_arm/start.c b/src/system/boot/platform/raspberrypi_arm/start.c
index c7ee41ed85..6b3de48b38 100644
--- a/src/system/boot/platform/raspberrypi_arm/start.c
+++ b/src/system/boot/platform/raspberrypi_arm/start.c
@@ -112,7 +112,7 @@ pi_start(void)
 	gpio_init();
 
 	// Flick on "OK" led, use pre-mmu firmware base
-	gpio_write(BCM2708_DEVICEFW_BASE + GPIO_BASE, 16, 0);
+	gpio_write(PERIPHERAL_BASE + GPIO_BASE, 16, 0);
 
 	mmu_init();