LowLevel/Luma3DS-3GX
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The ARM11 exception handlers are now working.

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Refactored the exception handling code in general.
This commit is contained in:
TuxSH
2016-06-03 21:38:35 +02:00
parent 2d7dde9cf9
commit bb230de72c
9 changed files with 61 additions and 86 deletions
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67
source/exceptions.c
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@@ -13,47 +13,20 @@
#include "../build/arm9_exceptions.h"
#include "../build/arm11_exceptions.h"
#define _U __attribute__((unused)) //Silence "unused parameter" warnings
static void __attribute__((naked)) setupStack(_U u32 mode, _U void* SP)
{
__asm__ volatile(
"cmp r0, #0 \n"
"moveq r0, #0xf @ usr => sys \n"
"mrs r2, cpsr \n"
"bic r3, r2, #0xf \n"
"orr r3, r0 @ processor mode \n"
"msr cpsr_c, r3 @ change processor mode \n"
"mov sp, r1 \n"
"msr cpsr_c, r2 @ restore processor mode \n"
"bx lr \n"
);
}
#undef _U
void installArm9Handlers(void)
{
void *payloadAddress = (void *)0x01FF8000;
u32 *handlers = (u32 *)payloadAddress + 1;
void* SP = (void *)0x02000000; //We make the (full descending) stack point to the end of ITCM for our exception handlers.
//It doesn't matter if we're overwriting stuff, since we're going to reboot.
memcpy(payloadAddress, arm9_exceptions, arm9_exceptions_size);
setupStack(1, SP); //FIQ
setupStack(7, SP); //Abort
setupStack(11, SP); //Undefined
void *payloadAddress = (void *)0x01FF8000;
const u32 offsets[] = {0x08, 0x18, 0x20, 0x28};
memcpy(payloadAddress, arm9_exceptions + 32, arm9_exceptions_size - 32);
//IRQHandler is at 0x08000000, but we won't handle it for some reasons
//svcHandler is at 0x08000010, but we won't handle svc either
for(u32 i = 0; i < 4; i++)
{
*(vu32 *)(0x08000000 + offsets[i]) = 0xE51FF004;
*(vu32 *)(0x08000000 + offsets[i] + 4) = handlers[i];
*(vu32 *)(0x08000000 + offsets[i] + 4) = *((const u32 *)arm9_exceptions + 1 + i);
}
}
@@ -67,25 +40,25 @@ void installArm11Handlers(u32 *exceptionsPage, u32 stackAddr)
u32 *mcuReboot;
for(mcuReboot = exceptionsPage; mcuReboot < (exceptionsPage + 0x400) && (mcuReboot[0] != 0xE59F4104 || mcuReboot[1] != 0xE3A0A0C2); mcuReboot += 1);
mcuReboot--;
u32 *freeSpace;
for(freeSpace = initFPU; freeSpace < (exceptionsPage + 0x400) && (freeSpace[0] != 0xFFFFFFFF || freeSpace[1] != 0xFFFFFFFF); freeSpace += 1);
//freeSpace += 4 - ((u32)(freeSpace - exceptionsPage) & 3);
memcpy(freeSpace, arm11_exceptions + 20, arm11_exceptions_size - 20);
memcpy(freeSpace, arm11_exceptions + 32, arm11_exceptions_size - 32);
exceptionsPage[1] = MAKE_BRANCH(exceptionsPage + 1, (u8 *)freeSpace + *(u32 *)(arm11_exceptions + 8) - 20); //Undefined Instruction
exceptionsPage[3] = MAKE_BRANCH(exceptionsPage + 3, (u8 *)freeSpace + *(u32 *)(arm11_exceptions + 12) - 20); //Prefetch Abort
exceptionsPage[4] = MAKE_BRANCH(exceptionsPage + 4, (u8 *)freeSpace + *(u32 *)(arm11_exceptions + 16) - 20); //Data Abort
exceptionsPage[7] = MAKE_BRANCH(exceptionsPage + 7, (u8 *)freeSpace + *(u32 *)(arm11_exceptions + 4) - 20); //FIQ
exceptionsPage[1] = MAKE_BRANCH(exceptionsPage + 1, (u8 *)freeSpace + *(u32 *)(arm11_exceptions + 8) - 32); //Undefined Instruction
exceptionsPage[3] = MAKE_BRANCH(exceptionsPage + 3, (u8 *)freeSpace + *(u32 *)(arm11_exceptions + 12) - 32); //Prefetch Abort
exceptionsPage[4] = MAKE_BRANCH(exceptionsPage + 4, (u8 *)freeSpace + *(u32 *)(arm11_exceptions + 16) - 32); //Data Abort
exceptionsPage[7] = MAKE_BRANCH(exceptionsPage + 7, (u8 *)freeSpace + *(u32 *)(arm11_exceptions + 4) - 32); //FIQ
for(u32 *pos = freeSpace; pos < (u32 *)((u8 *)freeSpace + arm11_exceptions_size - 20); pos++)
for(u32 *pos = freeSpace; pos < (u32 *)((u8 *)freeSpace + arm11_exceptions_size - 32); pos++)
{
switch(*pos)
switch(*pos) //Perform relocations
{
case 0xFFFF3000: *pos = stackAddr; break;
case 0xEBFFFFFE: *pos = MAKE_BRANCH_LINK(pos, initFPU); break;
case 0xEAFFFFFE: *pos = MAKE_BRANCH(pos, mcuReboot); break;
case 0xE12FFF1C: pos[1] = 0xFFFF0000 + 4 * (u32)(freeSpace - exceptionsPage) + pos[1] - 20; break; // bx r12 (mainHandler)
case 0xE12FFF1C: pos[1] = 0xFFFF0000 + 4 * (u32)(freeSpace - exceptionsPage) + pos[1] - 32; break; // bx r12 (mainHandler)
default: break;
}
}
@@ -171,13 +144,23 @@ void detectAndProcessExceptionDumps(void)
}
posY += 2 * SPACING_Y;
u32 mode = dump[40 + 16] & 0xF;
if(dump[4] == 3 && (mode == 7 || mode == 11))
posY = drawString("Incorrect dump: failed to dump code and/or stack", 10, posY, 0x00FFFF) + 2 * SPACING_Y; //in yellow
posY = drawString("You can find a dump in the following file:", 10, posY, COLOR_WHITE) + SPACING_Y;
posY = drawString((dump[3] == 9) ? path9 : path11, 10, posY, COLOR_WHITE) + 2 * SPACING_Y;
drawString("Press any button to shutdown", 10, posY, COLOR_WHITE);
waitInput();
i2cWriteRegister(I2C_DEV_MCU, 0x20, 1);
*(vu32 *)0x25000000 = 0; //Make sure we won't detect a corrupted exception dump after we've rebooted. It doesn't seem to be sufficient though
*(vu32 *)0x25000004 = 0;
clearScreens();
i2cWriteRegister(I2C_DEV_MCU, 0x20, 1); //Shutdown
while(1);
}
}

2
source/firm.c
View File

@@ -335,7 +335,7 @@ static inline void patchNativeFirm(u32 nandType, u32 emuHeader, u32 a9lhMode)
//Install arm11 exception handlers
u32 stackAddress;
u32 *exceptionsPage = getInfoForArm11ExceptionHandlers(arm11Section1, section[1].size, &stackAddress);
//installArm11Handlers(exceptionsPage, stackAddress);
installArm11Handlers(exceptionsPage, stackAddress);
//Make FCRAM (and VRAM as a side effect) globally executable from arm11 kernel
patchKernelFCRAMAndVRAMMappingPermissions(arm11Section1, section[1].size);