Improved power functions

source/common/cache.h

@@ -0,0 +1,43 @@
+/*
+*   This file is part of Luma3DS
+*   Copyright (C) 2016-2017 Aurora Wright, TuxSH
+*
+*   This program is free software: you can redistribute it and/or modify
+*   it under the terms of the GNU General Public License as published by
+*   the Free Software Foundation, either version 3 of the License, or
+*   (at your option) any later version.
+*
+*   This program is distributed in the hope that it will be useful,
+*   but WITHOUT ANY WARRANTY; without even the implied warranty of
+*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*   GNU General Public License for more details.
+*
+*   You should have received a copy of the GNU General Public License
+*   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*
+*   Additional Terms 7.b and 7.c of GPLv3 apply to this file:
+*       * Requiring preservation of specified reasonable legal notices or
+*         author attributions in that material or in the Appropriate Legal
+*         Notices displayed by works containing it.
+*       * Prohibiting misrepresentation of the origin of that material,
+*         or requiring that modified versions of such material be marked in
+*         reasonable ways as different from the original version.
+*/
+
+#pragma once
+
+#include "common.h"
+
+/***
+    The following functions flush the data cache, then waits for all memory transfers to be finished.
+    The data cache and/or the instruction cache MUST be flushed before doing one of the following:
+        - rebooting
+        - powering down
+        - setting the ARM11 entrypoint to execute a function
+        - jumping to a payload
+***/
+
+void flushEntireDCache(void); //actually: "clean and flush"
+void flushDCacheRange(void *startAddress, u32 size);
+void flushEntireICache(void);
+void flushICacheRange(void *startAddress, u32 size);

source/common/cache.s

@@ -0,0 +1,93 @@
+@   This file is part of Luma3DS
+@   Copyright (C) 2016-2017 Aurora Wright, TuxSH
+@
+@   This program is free software: you can redistribute it and/or modify
+@   it under the terms of the GNU General Public License as published by
+@   the Free Software Foundation, either version 3 of the License, or
+@   (at your option) any later version.
+@
+@   This program is distributed in the hope that it will be useful,
+@   but WITHOUT ANY WARRANTY; without even the implied warranty of
+@   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+@   GNU General Public License for more details.
+@
+@   You should have received a copy of the GNU General Public License
+@   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+@
+@   Additional Terms 7.b and 7.c of GPLv3 apply to this file:
+@       * Requiring preservation of specified reasonable legal notices or
+@         author attributions in that material or in the Appropriate Legal
+@         Notices displayed by works containing it.
+@       * Prohibiting misrepresentation of the origin of that material,
+@         or requiring that modified versions of such material be marked in
+@         reasonable ways as different from the original version.
+
+.text
+.arm
+.align 4
+
+.global flushEntireDCache
+.type flushEntireDCache, %function
+flushEntireDCache:
+    @ Adapted from http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0155a/ch03s03s05.html,
+    @ and https://github.com/gemarcano/libctr9_io/blob/master/src/ctr_system_ARM.c#L39 as well
+    @ Note: ARM's example is actually for a 8KB DCache (which is what the 3DS has)
+
+    @ Implemented in bootROM at address 0xffff0830
+    mov r1, #0                          @ segment counter
+    outer_loop:
+        mov r0, #0                      @ line counter
+
+        inner_loop:
+            orr r2, r1, r0                  @ generate segment and line address
+            mcr p15, 0, r2, c7, c14, 2      @ clean and flush the line
+            add r0, #0x20                   @ increment to next line
+            cmp r0, #0x400
+            bne inner_loop
+
+        add r1, #0x40000000
+        cmp r1, #0
+        bne outer_loop
+
+    mcr p15, 0, r1, c7, c10, 4              @ drain write buffer
+    bx lr
+
+.global flushDCacheRange
+.type flushDCacheRange, %function
+flushDCacheRange:
+    @ Implemented in bootROM at address 0xffff08a0
+    add r1, r0, r1                      @ end address
+    bic r0, #0x1f                       @ align source address to cache line size (32 bytes)
+
+    flush_dcache_range_loop:
+        mcr p15, 0, r0, c7, c14, 1      @ clean and flush the line corresponding to the address r0 is holding
+        add r0, #0x20
+        cmp r0, r1
+        blo flush_dcache_range_loop
+
+    mov r0, #0
+    mcr p15, 0, r0, c7, c10, 4          @ drain write buffer
+    bx lr
+
+.global flushEntireICache
+.type flushEntireICache, %function
+flushEntireICache:
+    @ Implemented in bootROM at address 0xffff0ab4
+    mov r0, #0
+    mcr p15, 0, r0, c7, c5, 0
+    bx lr
+
+.global flushICacheRange
+.type flushICacheRange, %function
+flushICacheRange:
+    @ Implemented in bootROM at address 0xffff0ac0
+    add r1, r0, r1                      @ end address
+    bic r0, #0x1f                       @ align source address to cache line size (32 bytes)
+
+    flush_icache_range_loop:
+        mcr p15, 0, r0, c7, c5, 1      @ flush the line corresponding to the address r0 is holding
+        add r0, #0x20
+        cmp r0, r1
+        blo flush_icache_range_loop
+
+    bx lr

source/common/power.c

@@ -0,0 +1,19 @@
+#include "power.h"
+#include "i2c.h"
+#include "cache.h"
+#include "ui.h"
+
+void Reboot() {
+    ClearScreenF(true, true, COLOR_STD_BG);
+    flushEntireDCache();
+    i2cWriteRegister(I2C_DEV_MCU, 0x20, 1 << 2);
+    while(true);
+}
+
+void PowerOff()
+{
+    ClearScreenF(true, true, COLOR_STD_BG);
+    flushEntireDCache();
+    i2cWriteRegister(I2C_DEV_MCU, 0x20, 1 << 0);
+    while (true);
+}

source/common/power.h

@@ -1,12 +1,6 @@
-#include "i2c.h"
+#pragma once
 
-inline static void Reboot() {
-    i2cWriteRegister(I2C_DEV_MCU, 0x20, 1 << 2);
-    while(true);
-}
+#include "common.h"
 
-inline static void PowerOff()
-{
-    i2cWriteRegister(I2C_DEV_MCU, 0x20, 1 << 0);
-    while (true);
-}
+void Reboot();
+void PowerOff();

source/main.c

@@ -19,6 +19,5 @@ void main(int argc, char** argv)
         bottom_screen = (u8*)(*(u32*)0x23FFFE08);
     }
     u32 godmode_exit = GodMode();
-    ClearScreenF(true, true, COLOR_STD_BG);
     (godmode_exit == GODMODE_EXIT_REBOOT) ? Reboot() : PowerOff();
 }