git: bd5dc94b998f - main - boot0: Expand the description of BOOT_BOOT0_ORG.

The branch main has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=bd5dc94b998fe9ea0cd2ce9fcaf8481465b95b27

commit bd5dc94b998fe9ea0cd2ce9fcaf8481465b95b27
Author:     John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2023-04-18 18:02:50 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2023-04-18 18:02:50 +0000

    boot0: Expand the description of BOOT_BOOT0_ORG.
    
    This really shouldn't even be an option given it is hardcoded as a
    constant named ORIGIN in the assembly.  mbr.S also uses 0x600 and
    hardcodes it in both the assembly and the Makefile.
---
 stand/i386/boot0/Makefile | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/stand/i386/boot0/Makefile b/stand/i386/boot0/Makefile
index 1453f17751b9..cd645011b8e7 100644
--- a/stand/i386/boot0/Makefile
+++ b/stand/i386/boot0/Makefile
@@ -36,8 +36,11 @@ BOOT_BOOT0_FLAGS?=	0x8f
 # 0xb6 (182d) corresponds to 10 seconds.
 BOOT_BOOT0_TICKS?=	0xb6
 
-# The base address that we the boot0 code to to run it.  Don't change this
-# unless you are glutton for punishment.
+# The BIOS loads boot0 to the hardcoded address 0x7c00.  boot0 copies
+# itself to this alternate base address before continuing execution so
+# that next level boot blocks can be loaded at the 0x7c00 address they
+# expect.  Don't change this unless you are glutton for punishment
+# (and fix ORIGIN in the source to match).
 BOOT_BOOT0_ORG?=	0x600
 ORG=${BOOT_BOOT0_ORG}