nasm-uefi/yo.asm

bits 64
org  0x200000
section .header

DOS:
    dd 0x00005a4d       
    times 14 dd 0
    dd 0x00000080
    times 16 dd 0

PECOFF:
        dd `PE\0\0`     ; sig
    dw 0x8664       ; type
    dw 3            ; sections
    dd 0x5cba52f6       ; timestamp
    dq 0            ; * symbol table + # symbols
    dw osize        ; oheader size
    dw 0x202e       ; characteristics

OHEADER:
    dd 0x0000020b       ; oheader + 0000 linker sig
    dd 4096 ;codesize       ; code size
    dd 8192 ;datasize       ; data size
    dd 0            ; uninitialized data size
    dd 4096         ; * entry
    dd 4096         ; * code base
    dq 0x200000        ; * image base
    dd 4096         ; section alignment
    dd 4096         ; file alignment
    dq 0            ; os maj, min, image maj, min
    dq 0            ; subsys maj, min, reserved
    dd 0x4000       ; image size
    dd 4096         ; headers size
    dd 0            ; checksum
    dd 0x0040000A       ; dll characteristics & subsystem
    dq 0x10000      ; stack reserve size
    dq 0x10000      ; stack commit size
    dq 0x10000      ; heap reserve size
    dq 0            ; heap reserve commit
    dd 0            ; loader flags
    dd 0x10         ; rva count

DIRS:
    times 5 dq 0        ; unused
    dd 0x004000        ; virtual address .reloc
    dd 0            ; size .reloc
        times 10 dq 0       ; unused 
OEND:
osize equ OEND - OHEADER

SECTS:
.1:
    dq  `.text`     ; name
    dd  4096 ;codesize      ; virtual size
    dd  4096        ; virtual address   
    dd  4096        ; raw data size
    dd  4096        ; * raw data
    dq  0           ; * relocations, * line numbers
    dd  0           ; # relocations, # line numbers
    dd  0x60000020      ; characteristics

.2:
        dq  `.data`
        dd  8192 ;datasize      
        dd  8192
        dd  8192 
        dd  8192       
        dq  0
        dd  0
        dd  0xC0000040      


.3:
    dq  `.reloc`
    dd  0   
    dd  0 ;20480
    dd  0
    dd  0 ;20480
    dq  0
    dd  0
    dd  0x02000040

    times 4096 - ($-$$) db 0  ;align the text section on a 4096 byte boundary

section .text follows=.header 

EFI_SUCCESS                                 equ 0
EFI_SYSTEM_TABLE_SIGNATURE                  equ 0x5453595320494249
EFI_SYSTEM_TABLE_CONOUT                         equ 64
EFI_SYSTEM_TABLE_RUNTIMESERVICES                equ 88
EFI_SYSTEM_TABLE_BOOTSERVICES                   equ 96

EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL_RESET           equ 0
EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL_OUTPUTSTRING        equ 8

EFI_BOOT_SERVICES_GETMEMORYMAP              equ 56
EFI_BOOT_SERVICES_LOCATEHANDLE              equ 176
EFI_BOOT_SERVICES_LOADIMAGE             equ 200
EFI_BOOT_SERVICES_EXIT                  equ 216
EFI_BOOT_SERVICES_EXITBOOTSERVICES          equ 232
EFI_BOOT_SERVICES_LOCATEPROTOCOL            equ 320

EFI_RUNTIME_SERVICES_RESETSYSTEM            equ 104


 sub rsp, 6*8    
 mov [Handle], rcx         
 mov [SystemTable], rdx    

 mov rax, [SystemTable]
 mov rax, [rax + EFI_SYSTEM_TABLE_BOOTSERVICES]
 mov [BS], rax

 mov rax, [SystemTable]
 mov rax, [rax + EFI_SYSTEM_TABLE_RUNTIMESERVICES]
 mov [RTS], rax

 lea rdx, [herewego]
 mov rcx, [SystemTable]
 mov rcx, [rcx + EFI_SYSTEM_TABLE_CONOUT]
 call [rcx + EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL_OUTPUTSTRING]

 ; get the memory map
 mov qword [memmapsize], 4096
 lea rcx, [memmapsize]
 lea rdx, [memmap]
 lea r8, [memmapkey]
 lea r9, [memmapdescsize]
 lea r10, [memmapdescver]
 mov [STK],rsp
 push r10
 sub rsp, 4*8
 mov rbx, [BS]
 call [rbx + EFI_BOOT_SERVICES_GETMEMORYMAP]
 add rsp, 4*8
 pop r10
 mov rsp, [STK]
 cmp rax, EFI_SUCCESS
 jne oops

 ; find the interface to GOP
 mov rbx, [SystemTable]
 mov rbx, [rbx + EFI_SYSTEM_TABLE_BOOTSERVICES]
 mov rcx, _EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID
 mov rdx, 0
 lea r8, [Interface]
 call [rbx + EFI_BOOT_SERVICES_LOCATEPROTOCOL]
 cmp rax, EFI_SUCCESS
 jne oops

 mov rcx, [Interface]
 mov rcx, [rcx + 0x18 ] ;EFI_GRAPHICS_OUTPUT_PROTOCOL_MODE
 mov rbx, [rcx + 0x18 ] ;EFI_GRAPHICS_OUTPUT_PROTOCOL_MODE_FRAMEBUFFERBASE
 mov [FB], rbx
 mov rcx, [rcx + 0x20 ] ;EFI_GRAPHICS_OUTPUT_PROTOCOL_MODE_FRAMEBUFFERSIZE
 mov [FBS], rcx
 cmp rax, EFI_SUCCESS
 jne oops

       mov rbx, [FB]
       push rax
       push rcx
       push rdx
       call printhex
       pop rdx
       pop rcx
       pop rax

       mov rbx, [FBS]
       push rax
       push rcx
       push rdx
       call printhex
       pop rdx
       pop rcx
       pop rax

 ; exit boot services
 mov rcx, [Handle]
 mov rdx, [memmapkey]
 mov rbx, [SystemTable]
 mov rbx, [rbx + EFI_SYSTEM_TABLE_BOOTSERVICES]
 call [rbx + EFI_BOOT_SERVICES_EXITBOOTSERVICES]
 cmp rax, EFI_SUCCESS
 je g5

       mov rbx, [memmapkey]
       push rax
       push rcx
       push rdx
       call printhex
       pop rdx
       pop rcx
       pop rax

 ; repeat the call to get the memory map
 mov qword [memmapsize], 4096
 lea rcx, [memmapsize]
 lea rdx, [memmap]
 lea r8, [memmapkey]
 lea r9, [memmapdescsize]
 lea r10, [memmapdescver]
 mov [STK],rsp
 push r10
 sub rsp, 4*8
 mov rbx, [BS]
 call [rbx + EFI_BOOT_SERVICES_GETMEMORYMAP]
 add rsp, 4*8
 pop r10
 mov rsp, [STK]
 cmp rax, EFI_SUCCESS
 jne oops

       mov rbx, [memmapkey]
       push rax
       push rcx
       push rdx
       call printhex
       pop rdx
       pop rcx
       pop rax

 ; exit boot services again
 mov rcx, [Handle]
 mov rdx, [memmapkey]
 xor r8, r8
 mov rbx, [SystemTable]
 mov rbx, [rbx + EFI_SYSTEM_TABLE_BOOTSERVICES]
 call [rbx + EFI_BOOT_SERVICES_EXITBOOTSERVICES]
 ;cmp rax, EFI_SUCCESS
 ;je g5
 ;jmp oops

Z:
 jmp Z

 mov rcx, [FB]
 mov rax, [FBS]
Q:
 dec rax
 mov byte[rcx+rax],255
 jnz Q

W:
 jmp W

g5:
 mov rcx, 2 ;EfiResetShutdown    
 mov rdx, EFI_SUCCESS
 mov rax, [SystemTable]
 mov rax, [rax + EFI_SYSTEM_TABLE_RUNTIMESERVICES]
 call [rax + EFI_RUNTIME_SERVICES_RESETSYSTEM]

oops:
 lea rdx, [fail]
 mov rcx, [SystemTable]
 mov rcx, [rcx + EFI_SYSTEM_TABLE_CONOUT]
 call [rcx + EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL_OUTPUTSTRING]
 jmp $-1

printhex:
 mov rbp, 16
.loop:
	rol rbx, 4
	mov rax, rbx
	and rax, 0Fh
	lea rcx, [_Hex]
	mov rax, [rax + rcx]
	mov byte [_Num], al
        lea rdx, [_Num]
        mov rcx, [SystemTable]
        mov rcx, [rcx + EFI_SYSTEM_TABLE_CONOUT]
        call [rcx + EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL_OUTPUTSTRING]
	dec rbp
 jnz .loop
 lea rdx, [_Nl]
 mov rcx, [SystemTable]
 mov rcx, [rcx + EFI_SYSTEM_TABLE_CONOUT] 
 call [rcx + EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL_OUTPUTSTRING]

 ret

    times 8192-($-$$) db 0  

codesize equ $ - $$

section .data follows=.text 

Handle          dq 0
SystemTable     dq 0
Interface       dq 0
BS		dq 0
RTS		dq 0
STK	        dq 0
FB              dq 0
FBS             dq 0
memmapsize      dq 4096
memmapkey       dq 0
memmapdescsize  dq 48
memmapdescver   dq 0

_EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID db 0xde, 0xa9, 0x42, 0x90, 0xdc, 0x23, 0x38, 0x4a
                                  db 0x96, 0xfb, 0x7a, 0xde, 0xd0, 0x80, 0x51, 0x6a
fail     db __utf16__ `fail.\r\n\0`
nok      db __utf16__ `Not OK.\r\n\0`
yok      db __utf16__ `OK.\r\n\0`
herewego db __utf16__ `here we go\r\n\0`
_Hex     db '0123456789ABCDEF'
_Num     dw 0,0
_Nl      dw 13,10,0

    times 4096-($-$$) db 0

memmap:
    times 4096 db 0

datasize equ $ - $$


section .reloc follows=.data