Changed the RB_PAUSE flag from 0x40000 to 0x100000 and marked the old

value as reserved for internal use in boot blocks, because RB_PAUSE
broke binary compatibility by usurping the RB_DUAL flag.  Probably no
one except me has boot blocks for which this matters, since most boot
blocks based on biosboot including pc98's boot2 can't boot elf kernels,
and /boot/loader doesn't properly pass flags set by the previous stage.

reboot.h:
Also mark the historical RB_PROBEKBD flag (0x80000) as reserved for
internal use in boot blocks.

boot2.c:
Added comments to inhibit usurping of other flags.

Approved by:	guido, imp
MFC after: 	1 week

3 files changed, 30 insertions, 6 deletions

diff --git a/sys/boot/i386/boot2/boot2.c b/sys/boot/i386/boot2/boot2.c
index 2f9971a..bb58353 100644
--- a/sys/boot/i386/boot2/boot2.c
+++ b/sys/boot/i386/boot2/boot2.c
@@ -41,19 +41,30 @@ __FBSDID("$FreeBSD$");
 
 #define RBX_ASKNAME	0x0	/* -a */
 #define RBX_SINGLE	0x1	/* -s */
+/* 0x2 is reserved for log2(RB_NOSYNC). */
+/* 0x3 is reserved for log2(RB_HALT). */
+/* 0x4 is reserved for log2(RB_INITNAME). */
 #define RBX_DFLTROOT	0x5	/* -r */
 #define RBX_KDB 	0x6	/* -d */
+/* 0x7 is reserved for log2(RB_RDONLY). */
+/* 0x8 is reserved for log2(RB_DUMP). */
+/* 0x9 is reserved for log2(RB_MINIROOT). */
 #define RBX_CONFIG	0xa	/* -c */
 #define RBX_VERBOSE	0xb	/* -v */
 #define RBX_SERIAL	0xc	/* -h */
 #define RBX_CDROM	0xd	/* -C */
+/* 0xe is reserved for log2(RB_POWEROFF). */
 #define RBX_GDB 	0xf	/* -g */
 #define RBX_MUTE	0x10	/* -m */
-#define RBX_PAUSE	0x12	/* -p */
+/* 0x11 is reserved for log2(RB_SELFTEST). */
+/* 0x12 is reserved for boot programs. */
+/* 0x13 is reserved for boot programs. */
+#define RBX_PAUSE	0x14	/* -p */
 #define RBX_NOINTR	0x1c	/* -n */
+/* 0x1d is reserved for log2(RB_MULTIPLE) and is just misnamed here. */
 #define RBX_DUAL	0x1d	/* -D */
 #define RBX_PROBEKBD	0x1e	/* -P */
-/* 0x1f is reserved for the RB_BOOTINFO flag. */
+/* 0x1f is reserved for log2(RB_BOOTINFO). */
 
 /* pass: -a, -s, -r, -d, -c, -v, -h, -C, -g, -m, -p, -D */
 #define RBX_MASK	0x2005ffff
diff --git a/sys/boot/i386/gptboot/gptboot.c b/sys/boot/i386/gptboot/gptboot.c
index 2f9971a..bb58353 100644
--- a/sys/boot/i386/gptboot/gptboot.c
+++ b/sys/boot/i386/gptboot/gptboot.c
@@ -41,19 +41,30 @@ __FBSDID("$FreeBSD$");
 
 #define RBX_ASKNAME	0x0	/* -a */
 #define RBX_SINGLE	0x1	/* -s */
+/* 0x2 is reserved for log2(RB_NOSYNC). */
+/* 0x3 is reserved for log2(RB_HALT). */
+/* 0x4 is reserved for log2(RB_INITNAME). */
 #define RBX_DFLTROOT	0x5	/* -r */
 #define RBX_KDB 	0x6	/* -d */
+/* 0x7 is reserved for log2(RB_RDONLY). */
+/* 0x8 is reserved for log2(RB_DUMP). */
+/* 0x9 is reserved for log2(RB_MINIROOT). */
 #define RBX_CONFIG	0xa	/* -c */
 #define RBX_VERBOSE	0xb	/* -v */
 #define RBX_SERIAL	0xc	/* -h */
 #define RBX_CDROM	0xd	/* -C */
+/* 0xe is reserved for log2(RB_POWEROFF). */
 #define RBX_GDB 	0xf	/* -g */
 #define RBX_MUTE	0x10	/* -m */
-#define RBX_PAUSE	0x12	/* -p */
+/* 0x11 is reserved for log2(RB_SELFTEST). */
+/* 0x12 is reserved for boot programs. */
+/* 0x13 is reserved for boot programs. */
+#define RBX_PAUSE	0x14	/* -p */
 #define RBX_NOINTR	0x1c	/* -n */
+/* 0x1d is reserved for log2(RB_MULTIPLE) and is just misnamed here. */
 #define RBX_DUAL	0x1d	/* -D */
 #define RBX_PROBEKBD	0x1e	/* -P */
-/* 0x1f is reserved for the RB_BOOTINFO flag. */
+/* 0x1f is reserved for log2(RB_BOOTINFO). */
 
 /* pass: -a, -s, -r, -d, -c, -v, -h, -C, -g, -m, -p, -D */
 #define RBX_MASK	0x2005ffff
diff --git a/sys/sys/reboot.h b/sys/sys/reboot.h
index dd84899..7412e42 100644
--- a/sys/sys/reboot.h
+++ b/sys/sys/reboot.h
@@ -61,9 +61,11 @@
 #define	RB_GDB		0x8000	/* use GDB remote debugger instead of DDB */
 #define	RB_MUTE		0x10000	/* start up with the console muted */
 #define	RB_SELFTEST	0x20000	/* don't complete the boot; do selftest */
-#define	RB_PAUSE	0x40000	/* pause after each output line during probe */
+#define	RB_RESERVED1	0x40000	/* reserved for internal use of boot blocks */
+#define	RB_RESERVED2	0x80000	/* reserved for internal use of boot blocks */
+#define	RB_PAUSE	0x100000 /* pause after each output line during probe */
 #define	RB_MULTIPLE	0x20000000	/* use multiple consoles */
 
 #define	RB_BOOTINFO	0x80000000	/* have `struct bootinfo *' arg */
 
-#endif /* !_SYS_REBOOT_H_ */
+#endif