fix broken cross-buffer assumption, check nvram reads

arm11/link.ld

@@ -4,7 +4,7 @@ ENTRY(__boot)
 
 MEMORY
 {
-    AXIWRAM (RWX) : ORIGIN = 0x1FF80000, LENGTH = 96K
+    AXIWRAM (RWX) : ORIGIN = 0x1FF80000, LENGTH = 128K
     HIGHRAM (RWX) : ORIGIN = 0xFFFF0000, LENGTH = 4K
 }
 

arm11/source/main.c

@@ -31,6 +31,7 @@
 #include "hw/nvram.h"
 
 #include "system/sys.h"
+#include "system/xalloc.h"
 
 static GlobalSharedMemory SharedMemory_State;
 
@@ -57,7 +58,7 @@ void VBlank_Handler(u32 __attribute__((unused)) irqn)
 	#endif
 
 	// the state should probably be stored on its own
-	// setion without caching enabled, since it must
+	// section without caching enabled, since it must
 	// be readable by the ARM9 at all times anyway
 	SharedMemory_State.hid_state = HID_GetState();
 	ARM_WbDC_Range(&SharedMemory_State, sizeof(SharedMemory_State));
@@ -158,6 +159,12 @@ void PXI_RX_Handler(u32 __attribute__((unused)) irqn)
 			break;
 		}
 
+		case PXI_XALLOC:
+		{
+			ret = (u32)XAlloc(args[0]);
+			break;
+		}
+
 		/* New CMD template:
 		case CMD_ID:
 		{

arm11/source/system/xalloc.c

@@ -0,0 +1,37 @@
+/*
+ *   This file is part of GodMode9
+ *   Copyright (C) 2019 Wolfvak
+ *
+ *   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 2 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/>.
+ */
+
+// super simple watermark allocator for ARM9 <-> ARM11 xfers
+// designed to be request once, free never
+
+#include "system/xalloc.h"
+
+static char xalloc_buf[XALLOC_BUF_SIZE];
+static size_t mark = 0;
+
+void *XAlloc(size_t size)
+{ // not thread-safe at all
+	void *ret;
+	size_t end = size + mark;
+	if (end >= XALLOC_BUF_SIZE)
+		return NULL;
+
+	ret = &xalloc_buf[mark];
+	mark = end;
+	return ret;
+}

arm11/source/system/xalloc.h

@@ -0,0 +1,25 @@
+/*
+ *   This file is part of GodMode9
+ *   Copyright (C) 2019 Wolfvak
+ *
+ *   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 2 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/>.
+ */
+
+#pragma once
+
+#include "types.h"
+
+#define XALLOC_BUF_SIZE	(16384)
+
+void *XAlloc(size_t size);

arm9/source/common/touchcal.c

@@ -106,7 +106,9 @@ bool CalibrateTouchFromFlash(void) {
  
     // check NVRAM console ID
     u32 console_id = 0;
-    spiflash_read(0x001C, 4, (u8*)&console_id);
+    if (!spiflash_read(0x001C, 4, (u8*)&console_id))
+        return false;
+
     if (((console_id >> 8) & 0xFF) != 0x57)
         return false; // not a 3DS
 
@@ -114,7 +116,9 @@ bool CalibrateTouchFromFlash(void) {
     // see: https://problemkaputt.de/gbatek.htm#dsfirmwareusersettings
     u32 fw_usercfg_buf[0x100 / 0x4];
     u8* fw_usercfg = (u8*) fw_usercfg_buf;
-    spiflash_read(0x1FE00, 0x100, fw_usercfg);
+    if (!spiflash_read(0x1FE00, 0x100, fw_usercfg))
+        return false;
+
     if (getle16(fw_usercfg + 0x72) != crc16_quick(fw_usercfg, 0x70))
         return false;
 

arm9/source/system/i2c.c

@@ -4,63 +4,57 @@
 #include "i2c.h"
 #include "pxi.h"
 
-/*
+// buffer is allocated only once and remains through runtime
- disgusting hack that deserves to die in hell
+static char *i2c_xfer_buf = NULL;
- ideally all buffers would be able to be accessed
- by the ARM11, but those in ARM9 RAM are inaccessible
- (.data, .rodata & .bss)
 
- the current hack assumes all buffers in the heap are
+static bool I2C_AllocBuffer(void)
- located in FCRAM, which is accessible to both processors
+{
- but it's horrendous, and hopefully temporary
+	if (!i2c_xfer_buf) {
-*/
+		u32 xbuf = PXI_DoCMD(PXI_XALLOC, (u32[]){256}, 1);
+		if (xbuf == 0 || xbuf == 0xFFFFFFFF)
+			return false;
+		i2c_xfer_buf = (char*)xbuf;
+	}
+	return true;
+}
 
-static char *i2c_fcram_buf = NULL;
 bool I2C_readRegBuf(I2cDevice devId, u8 regAddr, u8 *out, u32 size)
 {
-	if (!i2c_fcram_buf)
-		i2c_fcram_buf = malloc(256);
-
 	int ret;
-	u32 args[] = {devId, regAddr, (u32)i2c_fcram_buf, size};
+	u32 *args;
 
-	ARM_WbDC_Range(i2c_fcram_buf, size);
+	if (!I2C_AllocBuffer())
+		return false;
+
+	args = (u32[]){devId, regAddr, (u32)i2c_xfer_buf, size};
+
+	ARM_WbDC_Range(i2c_xfer_buf, size);
 	ARM_DSB();
 
 	ret = PXI_DoCMD(PXI_I2C_READ, args, 4);
 
-	ARM_InvDC_Range(i2c_fcram_buf, size);
+	ARM_InvDC_Range(i2c_xfer_buf, size);
-	memcpy(out, i2c_fcram_buf, size);
+	memcpy(out, i2c_xfer_buf, size);
 	return ret;
 }
 
 bool I2C_writeRegBuf(I2cDevice devId, u8 regAddr, const u8 *in, u32 size)
 {
-	if (!i2c_fcram_buf)
-		i2c_fcram_buf = malloc(256);
-
 	int ret;
-	u32 args[] = {devId, regAddr, (u32)i2c_fcram_buf, size};
 
-	memcpy(i2c_fcram_buf, in, size);
+	if (!I2C_AllocBuffer())
-	ARM_WbDC_Range(i2c_fcram_buf, size);
+		return false;
+
+	u32 args[] = {devId, regAddr, (u32)i2c_xfer_buf, size};
+
+	memcpy(i2c_xfer_buf, in, size);
+	ARM_WbDC_Range(i2c_xfer_buf, size);
 	ARM_DSB();
 
 	ret = PXI_DoCMD(PXI_I2C_WRITE, args, 4);
 	return ret;
 }
 
-/*bool I2C_readRegBuf(I2cDevice devId, u8 regAddr, u8 *out, u32 size)
-{
-	int ret;
-	u32 args[] = {devId, regAddr, (u32)out, size};
-	cpu_writeback_invalidate_dc_range(out, size);
-	cpu_membarrier();
-	ret = PXI_DoCMD(PXI_I2C_READ, args, 4);
-	cpu_invalidate_dc_range(out, size);
-	return ret;
-}*/
-
 u8 I2C_readReg(I2cDevice devId, u8 regAddr)
 {
 	u8 data;
@@ -69,16 +63,6 @@ u8 I2C_readReg(I2cDevice devId, u8 regAddr)
 	return data;
 }
 
-/*bool I2C_writeRegBuf(I2cDevice devId, u8 regAddr, const u8 *in, u32 size)
-{
-	int ret;
-	u32 args[] = {devId, regAddr, (u32)in, size};
-	cpu_writeback_dc_range(in, size);
-	cpu_membarrier();
-	ret = PXI_DoCMD(PXI_I2C_WRITE, args, 4);
-	return ret;
-}*/
-
 bool I2C_writeReg(I2cDevice devId, u8 regAddr, u8 data)
 {
 	return I2C_writeRegBuf(devId, regAddr, &data, 1);

arm9/source/system/spiflash.c

@@ -0,0 +1,44 @@
+#include "common.h"
+#include "arm.h"
+#include "pxi.h"
+
+#define SPIFLASH_CHUNK_SIZE	(0x1000)
+
+static char *spiflash_xalloc_buf = NULL;
+
+bool spiflash_get_status(void)
+{
+	return PXI_DoCMD(PXI_NVRAM_ONLINE, NULL, 0);
+}
+
+bool spiflash_read(u32 offset, u32 size, u8 *buf)
+{
+	u32 args[3];
+
+	if (!spiflash_xalloc_buf) {
+		u32 xbuf = PXI_DoCMD(PXI_XALLOC, (u32[]){SPIFLASH_CHUNK_SIZE}, 1);
+		if (xbuf == 0 || xbuf == 0xFFFFFFFF)
+			return false;
+		spiflash_xalloc_buf = (char*)xbuf;
+	}
+
+	args[1] = (u32)spiflash_xalloc_buf;
+
+	while(size > 0) {
+		u32 rem = min(size, SPIFLASH_CHUNK_SIZE);
+
+		args[0] = offset;
+		args[2] = rem;
+
+		ARM_DSB();
+		PXI_DoCMD(PXI_NVRAM_READ, args, 3);
+		ARM_InvDC_Range(spiflash_xalloc_buf, rem); 
+		memcpy(buf, spiflash_xalloc_buf, rem);
+
+		buf += rem;
+		size -= rem;
+		offset += rem;
+	}
+
+	return true;
+}

arm9/source/system/spiflash.h

@@ -25,16 +25,6 @@
 #define NVRAM_SIZE  0x20000 // 1 Mbit (128kiB)
 
 // true if spiflash is installed, false otherwise
-static inline bool spiflash_get_status(void)
+bool spiflash_get_status(void);
-{ // there should probably be a command for this...
-	return PXI_DoCMD(PXI_NVRAM_ONLINE, NULL, 0);
-}
 
-static inline void spiflash_read(u32 offset, u32 size, u8 *buf)
+bool spiflash_read(u32 offset, u32 size, u8 *buf);
-{
-	u32 args[] = {offset, (u32)buf, size};
-	ARM_WbDC_Range(buf, size);
-	ARM_DSB();
-	PXI_DoCMD(PXI_NVRAM_READ, args, 3);
-	ARM_InvDC_Range(buf, size);
-}

arm9/source/virtual/vmem.c

@@ -165,8 +165,9 @@ int ReadVMemNVRAM(const VirtualFile* vfile, void* buffer, u64 offset, u64 count)
         wififlash_initialized = spiflash_get_status();
         if (!wififlash_initialized) return 1;
     }
-    
+
-    spiflash_read((u32) offset, (u32) count, buffer);
+    if (!spiflash_read((u32) offset, (u32) count, buffer))
+        return 1;
     return 0;
 }
 

common/pxi.h

@@ -40,6 +40,8 @@ enum {
 
 	PXI_NOTIFY_LED,
 	PXI_BRIGHTNESS,
+
+	PXI_XALLOC,
 };
 
 /*