* Transcribed from Intel (as86) -> AT&T (gas) by Chris Noe, May 1999.
* <stiker@northlink.com>
*
- * Fix to work around buggy BIOSes which dont use carry bit correctly
+ * Fix to work around buggy BIOSes which don't use carry bit correctly
* and/or report extended memory in CX/DX for e801h memory size detection
* call. As a result the kernel got wrong figures. The int15/e801h docs
* from Ralf Brown interrupt list seem to indicate AX/BX should be used
# This is the setup header, and it must start at %cs:2 (old 0x9020:2)
.ascii "HdrS" # header signature
- .word 0x0203 # header version number (>= 0x0105)
+ .word 0x0204 # header version number (>= 0x0105)
# or else old loadlin-1.5 will fail)
realmode_swtch: .word 0, 0 # default_switch, SETUPSEG
start_sys_seg: .word SYSSEG
# can be located anywhere in
# low memory 0x10000 or higher.
-ramdisk_max: .long (MAXMEM-1) & 0x7fffffff
+ramdisk_max: .long (-__PAGE_OFFSET-(512 << 20)-1) & 0x7fffffff
# (Header version 0x0203 or later)
# The highest safe address for
# the contents of an initrd
trampoline: call start_of_setup
- .space 1024
+ .align 16
+ # The offset at this point is 0x240
+ .space (0xeff-0x240+1) # E820 & EDD space (ending at 0xeff)
# End of setup header #####################################################
start_of_setup:
# sizeof(e820rec).
#
good820:
- movb (E820NR), %al # up to 32 entries
+ movb (E820NR), %al # up to 128 entries
cmpb $E820MAX, %al
- jnl bail820
+ jae bail820
incb (E820NR)
movw %di, %ax
meme801:
stc # fix to work around buggy
- xorw %cx,%cx # BIOSes which dont clear/set
+ xorw %cx,%cx # BIOSes which don't clear/set
xorw %dx,%dx # carry on pass/error of
# e801h memory size call
# or merely pass cx,dx though
#
# but we yet haven't reloaded the CS register, so the default size
# of the target offset still is 16 bit.
-# However, using an operand prefix (0x66), the CPU will properly
+# However, using an operand prefix (0x66), the CPU will properly
# take our 48 bit far pointer. (INTeL 80386 Programmer's Reference
# Manual, Mixing 16-bit and 32-bit code, page 16-6)