ErrDisp

This system process handles displaying the error screens, such as "an error has occurred, the system needs shutdown". This can also display a register dump for exceptions, and info for fatal errors. (Normally the black-screen errors are displayed on retail, while the latter is displayed on development units.)

The register dump/fatal error info can also be written to nandrw/sys/native.log. On retail consoles, the system does not notify ErrDisp that any user-land exceptions occurred, ErrDisp is only notified for this on dev/debug units. Therefore, on retail consoles native.log only contains info from fatal errors. Starting with 5.0.0-11 ErrDisp no longer writes logs to native.log, except when the error-type is value 5 and when other checks with the errorinfo structure are successful (normally processes using this port never use error-type 5).

The bottom screen displays the error screen like "error has occurred", even with a development 3DS. The top screen can display the development error info, this is only displayed when UNITINFO bit0 is clear, for a development 3DS.

ErrDisp handles "returning" to Home Menu via NSS:RebootSystem, which triggers a hardware system reboot.

ErrDisp error port "err:f"

Command Header	Description
0x00010800	ThrowFatalError(0x80-byte errorinfo)
0x00020042	(size, (size<<14) | 2, errorinfoptr) This is similar to cmd1, except with this the input buffer is copied to final output errorinfo+0x80 instead of +0x0, via the ARM11 kernel. Max size is 0x100. ErrDisp doesn't do anything in the cmd-handler for this command at all, besides checking the command header and buffer header.

output, where *((u8*)errinfo) == 0 or 1

Entry	Format string	Format args	Description
PID	0x%08X_0x%08X	*(u32*)(errinfo + 0x10), *(u32*)(errinfo + 0x14)	Process ID
REV	%d	*(u16*)(errinfo + 2) | (*(u8*)(errinfo + 1) << 16)	?
AID	0x%08X_0x%08X	*(u32*)(errinfo + 0x18), *(u32*)(errinfo + 0x1C)	Application ID?
ADR	0x%08X	*(u32*)(errinfo + 8)	Address where the error was thrown from
RSL	0x%08X	*(u32*)(errinfo + 4)	Error code
Level	%d	*(u32*)(errinfo + 4) & 0x80000000 ? (*(u32*)(errinfo + 4) >> 27) - 0x20 : *(u32*)(errinfo + 4) >> 27	Error code level
Summary	%d	(*(u32*)(errinfo + 4) & 0x7E00000) >> 21	Error code summary
Module	%d	(*(u32*)(errinfo + 4) & 0x3FC00) >> 10	Error code module
Desc	%d	*(u32*)(errinfo + 4) & 0x3FF	Error code description
Datetime	%04d/%02d/%02d %02d:%02d:%02d	?	?

output, where *((u8*)errinfo) == 4

Entry	Format string	Format args	Description
PID	0x%08X_0x%08X	*(u32*)(errinfo + 0x10), *(u32*)(errinfo + 0x14)	Process ID
REV	%d	*(u16*)(errinfo + 2) | (*(u8*)(errinfo + 1) << 16)	?
AID	0x%08X_0x%08X	*(u32*)(errinfo + 0x18), *(u32*)(errinfo + 0x1C)	Application ID?
RSL	0x%08X	*(u32*)(errinfo + 4)	Error code
Level	%d	*(u32*)(errinfo + 4) & 0x80000000 ? (*(u32*)(errinfo + 4) >> 27) - 0x20 : *(u32*)(errinfo + 4) >> 27	Error code level
Summary	%d	(*(u32*)(errinfo + 4) & 0x7E00000) >> 21	Error code summary
Module	%d	(*(u32*)(errinfo + 4) & 0x3FC00) >> 10	Error code module
Desc	%d	*(u32*)(errinfo + 4) & 0x3FF	Error code description
?	%.*s	0x2E, for (int i = 0; i < 2; i++) errinfo + (i * 46) + 0x20	?
Datetime	%04d/%02d/%02d %02d:%02d:%02d	?	?