macOS Debug boot-args

debug.h

/* Debug boot-args */
#define DB_HALT			0x1.  /* Halt at boot-time and wait for debugger attach (gdb) */	
//#define DB_PRT          	0x2   /* Send kernel debugging printf output to console */ -- obsolete 
#define DB_NMI			0x4   /* Drop into debugger on NMI (Command–Power, Command-Option-Control-Shift-Escape,  
				      /* or interrupt switch) */
#define DB_KPRT			0x8   /* Send kernel debugging kprintf output to serial port*/
#define DB_KDB			0x10  /* Make ddb (kdb) the default debugger (requires a custom kernel) */
//#define DB_SLOG		0x20  /* Output certain diagnostic info to the system log */ -- obsolete
#define DB_ARP          	0x40  /* Allow debugger to ARP and route (allows debugging across routers and removes 
				      /* the need for a permanent ARP entry, but is a potential security hole)—not 
				      /* available in all kernels */
#define DB_KDP_BP_DIS   	0x80  /* Support old versions of gdb on newer systems */
//#define DB_LOG_PI_SCRN  	0x100 /* Disable graphical panic dialog */ -- obsolete
#define DB_KDP_GETC_ENA 	0x200 /* (useful) enable kdp_getc() prompt for (c) continue/(r) reboot */
#define DB_KERN_DUMP_ON_PANIC	0x400  /* Trigger core dump on panic*/
#define DB_KERN_DUMP_ON_NMI	0x800  /* Trigger core dump on NMI */
#define DB_DBG_POST_CORE	0x1000 /* Wait in debugger after NMI core */
#define DB_PANICLOG_DUMP	0x2000 /* Send paniclog on panic,not core */
#define DB_REBOOT_POST_CORE	0x4000 /* Attempt to reboot after */ post-panic crashdump/paniclog dump */
#define DB_NMI_BTN_ENA  	0x8000  /* Enable button to directly trigger NMI */
#define DB_PRT_KDEBUG   	0x10000 /* kprintf KDEBUG traces */
#define DB_DISABLE_LOCAL_CORE  0x20000 /* ignore local kernel core dump support */
#define DB_DISABLE_GZIP_CORE   0x40000 /* don't gzip kernel core dumps */