|
[ORG 0x10000]
[BITS 32]
; assemble using 'nasm' assembler
; C:>nasm header.asm -o simple.xbe
; XBE HEADER PART
------------------------------------------------------------
db 'XBEH'
resb 0x100 ; reserve 100 bytes for the
xbe security signature
; This only matters on
signed xbe's which are
; ms authorised :)
dd 0x10000 ; Base address of image
dd 0x760 ; Size of header
dd 0x7000 ; Size of image
dd 0x178 ; Size of image header
dd 0x3f16d3ce ; Time Date Stamp
dd cert_header ; Certificate Address (plus
offset)
dd 0x1 ; Number of sections
dd section_header ; Sectrion headers
Address(plus offset)
dd 0x1 ; Initialisation Flags
dd 0x11100 ^ 0xA8FC57AB
; Entry point (XOR with
0xA8FC57AB)
; ***** Very important -
this will be our entry
; point for our code - which
is the base address of
; our file added to the
actual file offset.
dd 0x16000 ; Thread local storage
directory address
dd 0x0 ; Size of stack commit
dd 0x0 ; Size of heap reserve
dd 0x0 ; Size of heap commit
dd 0x0 ; Original base address
dd 0x0 ; Original size of image
dd 0x0 ; Original checksum
dd 0x3f16d3ce ; Original time date stamp
dd debugpath ; Debug path name address
dd debugpath
dd szname
dd 0x11000 ^ 0x5B6D40B6
; Kernel image thunk address
; We XOR the original
address with 0x5B6D40B6
dd 0x0 ; Non-kernel import directory
address
dd 0x0 ; Number of library versions
dd 0x0 ; Library versions area addresses
dd 0x3 ; Kernel library version address
dd 0x0 ; XAPI library version address
dd 0 ; Logo bitmap address
dd 0 ; Logo bitmap size
; Not included a logo bitmap
for this simple example
; and will still run without
it, but you could encode
; a really cool image logo
for you app maybe :)
; Note: - a lot of assemblers use "[ORG 0x354]" to
align data within the assembled
; file, but for nasm, you have to use: TIMES
0x178-($-$$), which implies
; that everything from this line is from
0x178 in the file.
; XBE CERTIFICATION
----------------------------------------------------------
TIMES 0x178-($-$$) DB 0 ; I've aligned the
certificate to exactly 0x178 in
; the file, but you could
exclude this if you want.
cert_header:
dd 0x1dc ; Size of Certification
dd 0x3f16d3ce ; Date Stamp
dd 0x0 ; Title ID
resb 0x50 ; Title name null terminated
string
resb 0x40 ; Alt Title
dd 0x0 ; Allowed Media
dd 0x0 ; Game Region
dd 0x0 ; Game Rating
dd 0x0 ; Disk Number
dd 0x0 ; version
resb 0x10 ; Lan
resb 0x10 ; Signature Key
resb 0x100 ; Alt Sig
; SECTION HEADERS
------------------------------------------------------------
TIMES 0x354-($-$$) DB 0 ; Similar to the xbe cert
header, I've aligned the
; single section header to
offset 0x354 exactly, but
; you don't have to.
section_header:
dd 0x07 ; Flags
dd 0x11000 ; Virtual Address (remember
offset of 0x10000)
dd 0x6000 ; Virutal Size
dd 0x1000 ; File pointer to raw data
dd 0x6000 ; Size of raw data
dd section_name ; Address of the section
name (Null terminated)
dd 0x0 ;
dd rc1 ; head_count_address
dd rc2 ; tail_count_address
debugpath:
db 0x0,0x0,0x0,0x0,0x0,0,0,0,0,0,0,0,0,0,0
szname:
dw 'x','b','d','e','v',0,0,0
rc1:
dd 0
rc2:
dd 0
section_name:
db '.','t','e','x','t',0,0
; 'OUR CODE'
; THE SECTION WE DEFINED
-----------------------------------------------------
; This is the start of our section.. the start of
our simple
; code.
; Its offset in the file is at 0x1000
TIMES 0x1000-($-$$) DB 0
section_1_start: ; this should be 0x11000 in
memory when loaded
; kernel thunk table
MmAllocateContiguousMemoryEx:
dd 0x80000000 + 166
MmGetPhysicalAddress:
dd 0x80000000 + 173
NtAllocateVirtualMemory:
dd 0x80000000 + 184
dd 0 ; end of table
; Entry point of our code - offset 0x1100 in the
file.
TIMES 0x1100-($-$$) DB 0x90 ; this should be
0x11100 in memory when loaded
; Fantastic testing assembly function, which can be
found on xbox-linux site
; also, its used here to make sure our xbe is loaded
into memory okay, and is
; started :) This would be the point where you code
would go... the rest of
; its all over-head
flashingleds:
mov dx, 0xc004
mov al, 0x20
out dx, al
mov dx, 0xc008
mov al, 8
out dx, al
mov dx, 0xc006
; c = 0x80 + 0x04 + 0x20 + 0x02= 0xA6
mov al, 0xA6
out dx, al
mov dx, 0xc000
in ax, dx
out dx, al
mov dx, 0xc002
mov al, 0x1a
out dx, al
mov eax, 1000000
loopx:
dec eax
jne loopx
mov dx, 0xc004
mov al, 0x20
out dx, al
mov dx, 0xc008
mov al, 7
out dx, al
mov dx, 0xc006
mov al, 1
out dx, al
mov dx, 0xc000
in ax, dx
out dx, al
mov dx, 0xc002
mov al, 0x1a
out dx, al
aa:
jmp aa
TIMES 0x6000-($-$$) DB 0x90 ; this will make our
section finish at 0x6000
; from the start of
the file.
TIMES 0x7000-($-$$) DB 0x0 ; And of course, this
will make our file size
; equal to 0x7000 a
nice round number -
; 0x7000 is
28672bytes... so if you assemble the file
; you should find
its that size exactly. |
