Allow running GodMode9 in any environment

Makefile

@@ -139,7 +139,8 @@ binary: common
 	@$(MAKE) --no-print-directory -C $(BUILD) -f $(CURDIR)/Makefile
 
 firm: binary screeninit
-	firmtool build $(OUTPUT).firm -D $(OUTPUT).elf $(OUTPUT_D)/screeninit.elf -C NDMA XDMA
+	firmtool build $(OUTPUT).firm -n 0x08006000 -A 0x08006000 -D $(OUTPUT).bin $(OUTPUT_D)/screeninit.elf -C NDMA XDMA -S nand-retail
+	firmtool build $(OUTPUT)_dev.firm -n 0x08006000 -A 0x08006000 -D $(OUTPUT).bin $(OUTPUT_D)/screeninit.elf -C NDMA XDMA -S nand-dev
 
 gateway: binary
 	@cp resources/LauncherTemplate.dat $(OUTPUT_D)/Launcher.dat
@@ -172,6 +173,7 @@ release:
 	#@[ -d $(RELEASE)/$(TARGET) ] || mkdir -p $(RELEASE)/$(TARGET)
 	@cp $(OUTPUT).bin $(RELEASE)
 	@cp $(OUTPUT).firm $(RELEASE)
+	#@cp $(OUTPUT)_dev.firm $(RELEASE)
 	#@-cp $(OUTPUT).dat $(RELEASE)
 	#@-cp $(OUTPUT).nds $(RELEASE)
 	#@-cp $(OUTPUT).3dsx $(RELEASE)/$(TARGET)

link.ld

@@ -5,6 +5,7 @@ ENTRY(_start)
 SECTIONS
 {
     . = 0x23F00000;
+    __start__ = ABSOLUTE(.);
 
     .text.start : ALIGN(4) { *(.text.start) }
     .text       : ALIGN(4) { *(.text*) }
@@ -15,4 +16,7 @@ SECTIONS
     . = ALIGN(4);
 
     __end__ = ABSOLUTE(.);
+
+    __stack_top = __start__;
+    __code_size__ = __end__ - __start__;
 }

screeninit/source/main.c

@@ -7,12 +7,13 @@
 #define PDN_GPU_CNT (*(vu8  *)0x10141200)
 #define ARESCREENSINITIALIZED (PDN_GPU_CNT != 1)
 
-#define BRIGHTNESS 0x39
+#define BRIGHTNESS (0xBF)
 
 void main(void)
 {
+    char do_disco = !ARESCREENSINITIALIZED;
     vu32 *arm11Entry = (vu32 *)0x1FFFFFFC;
-    if (ARESCREENSINITIALIZED) return; // nothing to do in that case
+    u32 entry;
 
     *(vu32 *)0x10141200 = 0x1007F;
     *(vu32 *)0x10202014 = 0x00000001;
@@ -53,10 +54,6 @@ void main(void)
     *(vu32 *)0x10400490 = 0x000002D0;
     *(vu32 *)0x1040049C = 0x00000000;
 
-    //Disco register
-    for(u32 i = 0; i < 256; i++)
-        *(vu32 *)0x10400484 = 0x10101 * i;
-
     //Bottom screen
     *(vu32 *)0x10400500 = 0x000001c2;
     *(vu32 *)0x10400504 = 0x000000d1;
@@ -80,16 +77,19 @@ void main(void)
     *(vu32 *)0x1040055C = 0x00f00140;
     *(vu32 *)0x10400560 = 0x01c100d1;
     *(vu32 *)0x10400564 = 0x01920052;
-    *(vu32 *)0x10400568 = 0x18300000 + 0x46500;
+    *(vu32 *)0x10400568 = 0x18346500;
     *(vu32 *)0x10400570 = 0x80301;
     *(vu32 *)0x10400574 = 0x00010501;
     *(vu32 *)0x10400578 = 0;
     *(vu32 *)0x10400590 = 0x000002D0;
     *(vu32 *)0x1040059C = 0x00000000;
 
-    //Disco register
+    if (do_disco) {
-    for(u32 i = 0; i < 256; i++)
+        for(u32 i = 0; i < 256; i++) {
+            *(vu32 *)0x10400484 = 0x10101 * i;
             *(vu32 *)0x10400584 = 0x10101 * i;	
+        }
+    }
 
     //Set CakeBrah framebuffers
     fb->top_left = (u8 *)0x18300000;
@@ -118,12 +118,10 @@ void main(void)
 
     while(!((REGs_PSC0[3] & 2) && (REGs_PSC1[3] & 2)));
 
-    //Clear ARM11 entrypoint
+    // Clear ARM11 entrypoint
     *arm11Entry = 0;
 
-    //Wait for the entrypoint to be set
+    //Wait for the entrypoint to be set, then branch to it
-    while(!*arm11Entry);
+    while((entry=*arm11Entry) == 0);
-
+    ((void (*)())(entry))();
-    //Jump to it
-    ((void (*)())*arm11Entry)();
 }

source/common/ui.h

@@ -52,8 +52,8 @@
 #define COLOR_STD_BG        COLOR_BLACK
 #define COLOR_STD_FONT      COLOR_WHITE
 
-#define TOP_SCREEN          top_screen
+#define TOP_SCREEN          ((u8*)(*(u32*)0x23FFFE00))
-#define BOT_SCREEN          bottom_screen
+#define BOT_SCREEN          ((u8*)(*(u32*)0x23FFFE08))
 
 #ifdef SWITCH_SCREENS
 #define MAIN_SCREEN         TOP_SCREEN
@@ -67,8 +67,6 @@
 #define SCREEN_WIDTH_ALT    SCREEN_WIDTH_TOP
 #endif
 
-extern u8 *top_screen, *bottom_screen;
-
 void ClearScreen(unsigned char *screen, int color);
 void ClearScreenF(bool clear_main, bool clear_alt, int color);
 void DrawRectangle(u8* screen, int x, int y, int width, int height, int color);

source/main.c

@@ -1,28 +1,16 @@
 #include "common.h"
 #include "godmode.h"
-#include "ui.h"
 #include "i2c.h"
 #include "power.h"
 
-u8 *top_screen, *bottom_screen;
-
 void main(int argc, char** argv)
 {
+    (void) argc; // unused for now
+    (void) argv; // unused for now
+    
     // Turn on backlight
     I2C_writeReg(I2C_DEV_MCU, 0x22, 0x2A);
     
-    // Fetch the framebuffer addresses
-    if(argc >= 2) {
-        // newer entrypoints
-        u8 **fb = (u8 **)(void *)argv[1];
-        top_screen = fb[0];
-        bottom_screen = fb[2];
-    } else {
-        // outdated entrypoints
-        top_screen = (u8*)(*(u32*)0x23FFFE00);
-        bottom_screen = (u8*)(*(u32*)0x23FFFE08);
-    }
-    
     // Run the main program
     (GodMode() == GODMODE_EXIT_REBOOT) ? Reboot() : PowerOff();
 }

source/nand/nand.c

@@ -145,9 +145,9 @@ bool InitNandCrypto(void)
     for(u32 i = 0; i < 16; i++) // little endian and reversed order
         TwlNandCtr[i] = shasum[15-i];
     
-    // part #2: TWL KEY
+    // part #2: TWL KEY (if not already set up
     // see: https://www.3dbrew.org/wiki/Memory_layout#ARM9_ITCM
-    if (IS_A9LH && !IS_SIGHAX) { // only for a9lh
+    if (GetNandPartitionInfo(NULL, NP_TYPE_FAT, NP_SUBTYPE_TWL, 0, NAND_SYSNAND) != 0) {
         u8 TwlKeyY[16] __attribute__((aligned(32)));
 
         // k9l already did the part of the init that required the OTP registers
@@ -181,22 +181,27 @@ bool InitNandCrypto(void)
         use_aeskey(0x03);
     }
     
-    // part #3: CTRNAND N3DS KEY / AGBSAVE CMAC KEY
+    // part #3: CTRNAND N3DS KEY (if not set up)
     // thanks AuroraWright and Gelex for advice on this
     // see: https://github.com/AuroraWright/Luma3DS/blob/master/source/crypto.c#L347
-    if (IS_A9LH && !IS_SIGHAX) { // only on A9LH, not required on sighax
+    if (GetNandPartitionInfo(NULL, NP_TYPE_FAT, NP_SUBTYPE_CTR, 0, NAND_SYSNAND) != 0) {
+        if (IS_A9LH && !IS_SIGHAX) { // only on A9LH
             // keyY 0x05 is encrypted @0x0EB014 in the FIRM90
             // keyY 0x05 is encrypted @0x0EB24C in the FIRM81
             if ((LoadKeyYFromP9(slot0x05KeyY, slot0x05KeyY_sha256, 0x0EB014, 0x05) != 0) &&
                 (LoadKeyYFromP9(slot0x05KeyY, slot0x05KeyY_sha256, 0x0EB24C, 0x05) != 0))
                 LoadKeyFromFile(slot0x05KeyY, 0x05, 'Y', NULL);
+        } else LoadKeyFromFile(slot0x05KeyY, 0x05, 'Y', NULL);
+    }
     
+    // part #4: AGBSAVE CMAC KEY (source see above)
+    if (IS_A9LH && !IS_SIGHAX) { // only on A9LH
         // keyY 0x24 is encrypted @0x0E62DC in the FIRM90
         // keyY 0x24 is encrypted @0x0E6514 in the FIRM81
         if ((LoadKeyYFromP9(NULL, slot0x24KeyY_sha256, 0x0E62DC, 0x24) != 0) &&
             (LoadKeyYFromP9(NULL, slot0x24KeyY_sha256, 0x0E6514, 0x24) != 0))
             LoadKeyFromFile(NULL, 0x24, 'Y', NULL);
-    }
+    } else LoadKeyFromFile(NULL, 0x24, 'Y', NULL);
     
     return true;
 }

source/start.s

@@ -1,86 +1,50 @@
 .section .text.start
-.global _start
 .align 4
 .arm
 
-@ if the binary is booted from Brahma/CakeHax/k9lh
+@ make sure not to clobber r0-r2
-@ the entrypoint is <start + 0x0>
+.global _start
-@ framebuffers are already set
 _start:
-    nop
+    @ Switch to supervisor mode and disable interrupts
-    nop
+    msr cpsr_c, #0xD3
-    nop
-    nop
-    nop
-    nop
-    nop
-    nop
-    nop
-    nop
-    nop @ dummy
-    b _skip_gw
 
-@ if the binary is booted from the GW exploit
+    @ Short delay (not always necessary, just in case)
-@ the entrypoint is <start + 0x30>
+    mov r3, #0x40000
-_start_gw:
+    .Lwaitloop:
+        subs r3, #1
+        bgt .Lwaitloop
 
-    @@wait for the arm11 kernel threads to be ready
+    @ Check the load address
-    mov r1, #0x10000
+    adr r3, _start
-    waitLoop9:
+    ldr r4, =__start__
-        sub r1, #1
+    cmp r3, r4
-        cmp r1, #0
+    beq _start_gm
-        bgt waitLoop9
 
-    mov r1, #0x10000
+    @ Relocate the binary to the correct location and branch to it
-    waitLoop92:
+    ldr r5, =__code_size__
-        sub r1, #1
+    .Lbincopyloop:
-        cmp r1, #0
+        subs r5, #4
-        bgt waitLoop92
+        ldrge r6, [r3, r5]
+        strge r6, [r4, r5]
+        bge .Lbincopyloop
 
-
+    mov r5, r0
-    @ copy the payload to the standard entrypoint (0x23F00000)
+    mov r6, r1
-    adr r0, _start
+    mov r7, r2
-    add r1, r0, #0x100000
+    ldr r3, =0xFFFF0830       @ Writeback & Invalidate DCache
-    ldr r2, .entry
-    .copy_binary_fcram:
-        cmp r0, r1
-        ldrlt r3, [r0], #4
-        strlt r3, [r2], #4
-        blt .copy_binary_fcram
-
-    @ setup framebuffers to look like Brahma/etc
-
-    ldr r0, .gw_fba
-    ldr r1, [r0, #0x18]
-    and r1, #1
-    ldr r1, [r0, r1, lsl #2] @ r1 := top framebuffer loc
-    mov r2, r1               @ r2 := top framebuffer loc
-
-    ldr r0, .gw_fbb
-    ldr r3, [r0, #0xC]
-    and r3, #1
-    ldr r3, [r0, r3, lsl #2] @ r3 := bottom framebuffer loc
-
-    ldr r0, .cakehax
-    stmia r0, {r1,r2,r3}
-    @ framebuffers properly set
-
-    ldr r3, =0xFFFF0830         @ flush (clean & invalidate) entire dcache b9 func
     blx r3
+    mov r0, r5
+    mov r1, r6
+    mov r2, r7
 
-    mov r3, #0
+    mov lr, #0
-    mcr p15, 0, r3, c7, c5, 0   @ invalidate I-cache
+    mcr p15, 0, lr, c7, c5, 0 @ Invalidate ICache
 
-    mov r2, #0
+    bx r4
-    ldr r3, .entry
-    bx r3
 
-.gw_fba:  .word 0x080FFFC0
+_start_gm:
-.gw_fbb:  .word 0x080FFFD0
+    ldr sp, =__stack_top
-.cakehax: .word 0x23FFFE00
-.entry:   .word 0x23F00000
 
-_skip_gw:
     mov r9, r0      @ argc
     mov r10, r1     @ argv
 
@@ -102,11 +66,10 @@ _skip_gw:
     ldr r0, =__bss_start
     ldr r1, =__bss_end
     mov r2, #0
-
+    .Lbss_clr:
-    .bss_clr:
         cmp r0, r1
         strlt r2, [r0], #4
-        blt .bss_clr
+        blt .Lbss_clr
 
     @ Invalidate caches
     mov r5, #0
@@ -121,14 +84,14 @@ _skip_gw:
 
     @ Sets MPU permissions and cache settings
     ldr r0, =0xFFFF001F	@ ffff0000 64k  | bootrom (unprotected / protected)
-    ldr r1, =0x3000801B	@ 30000000 16k  | dtcm
+    ldr r1, =0x3000801B	@ 30008000 16k  | dtcm
     ldr r2, =0x01FF801D	@ 01ff8000 32k  | itcm
     ldr r3, =0x08000029	@ 08000000 2M   | arm9 mem (O3DS / N3DS)
     ldr r4, =0x10000029	@ 10000000 2M   | io mem (ARM9 / first 2MB)
     ldr r5, =0x20000037	@ 20000000 256M | fcram (O3DS / N3DS)
     ldr r6, =0x1FF00027	@ 1FF00000 1M   | dsp / axi wram
     ldr r7, =0x1800002D	@ 18000000 8M   | vram (+ 2MB)
-    mov r8, #0x2D
+    mov r8, #0b00101101 @ bootrom/itcm/arm9 mem and fcram are cacheable/bufferable
     mcr p15, 0, r0, c6, c0, 0
     mcr p15, 0, r1, c6, c1, 0
     mcr p15, 0, r2, c6, c2, 0
@@ -145,6 +108,13 @@ _skip_gw:
     ldr r1, =0x3000800A        @ set dtcm
     mcr p15, 0, r1, c9, c1, 0  @ set the dtcm Region Register
 
+    @ Wait for screen init
+    mov r0, #0x20000000
+    .Lwaitforsi:
+        ldr r1, [r0, #-4]
+        cmp r1, #0
+        bne .Lwaitforsi
+
     @ Enable caches
     mrc p15, 0, r4, c1, c0, 0  @ read control register
     orr r4, r4, #(1<<18)       @ - itcm enable
@@ -159,10 +129,6 @@ _skip_gw:
     mov r1, #0x340
     str r1, [r0]
 
-    ldr sp, =0x23F00000
-
     mov r0, r9
     mov r1, r10
     b main
-
-.pool