From fe5967a09f12cc09640d8284ac6f554ee3bf4357 Mon Sep 17 00:00:00 2001
From: Jonas Hvid <mail@johv.dk>
Date: Mon, 5 Oct 2020 06:22:27 +0200
Subject: [PATCH] Use Graphics Output Protocol to draw a rectangle

---
 main.asm | 46 ++++++++++++++++++++++++++++++++++++++++++++--
 uefi.f   | 25 ++++++++++++++++++++++++-
 2 files changed, 68 insertions(+), 3 deletions(-)

diff --git a/main.asm b/main.asm
index 54b2a5d..e510410 100644
--- a/main.asm
+++ b/main.asm
@@ -599,13 +599,55 @@ forth_asm EFICALL2, 'EFICALL2'
   pop rdx ; 2nd argument
   pop rcx ; 1st argument
 
-  push rsi
+  sub rsp, 32
+  call rax
+  add rsp, 32
+
+  next
+
+forth_asm EFICALL3, 'EFICALL3'
+  pop rax ; function pointer
+  pop r8  ; 3rd argument
+  pop rdx ; 2nd argument
+  pop rcx ; 1st argument
 
   sub rsp, 32
   call rax
   add rsp, 32
 
-  pop rsi
+  push rax
+
+  next
+
+forth_asm EFICALL10, 'EFICALL10'
+  pop rax ; function pointer
+
+  mov rcx, [rsp + 8 * 9]
+  mov rdx, [rsp + 8 * 8]
+  mov r8, [rsp + 8 * 7]
+  mov r9, [rsp + 8 * 6]
+
+  ;; Reverse order of stack arguments
+  mov r10, [rsp + 8 * 5]
+  mov r11, [rsp + 8 * 0]
+  mov [rsp + 8 * 5], r11
+  mov [rsp + 8 * 0], r10
+
+  mov r10, [rsp + 8 * 4]
+  mov r11, [rsp + 8 * 1]
+  mov [rsp + 8 * 4], r11
+  mov [rsp + 8 * 1], r10
+
+  mov r10, [rsp + 8 * 3]
+  mov r11, [rsp + 8 * 2]
+  mov [rsp + 8 * 3], r11
+  mov [rsp + 8 * 2], r10
+
+  sub rsp, 32
+  call rax
+  add rsp, 32 + 8 * 10
+
+  push rax
 
   next
 
diff --git a/uefi.f b/uefi.f
index 03587a8..91ea453 100644
--- a/uefi.f
+++ b/uefi.f
@@ -2,6 +2,18 @@
 : ConOut.OutputString ConOut 8 + @ ;
 : ConOut.OutputString() ConOut SWAP ConOut.OutputString EFICALL2 ;
 
+: BootServices SystemTable 96 + @ ;
+: BootServices.LocateProtocol BootServices 320 + @ ;
+: BootServices.LocateProtocol(GOP)
+  HERE @ 5348063987722529246 , 7661046075708078998 , \ *Protocol = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID
+  0 \ *Registration
+  HERE @ 0 , \ **Interface
+  BootServices.LocateProtocol EFICALL3 DROP
+  HERE @ 8 - @ \ *Interface
+  ;
+: GOP.Blt BootServices.LocateProtocol(GOP) 16 + @ ;
+: GOP.SetMode BootServices.LocateProtocol(GOP) 8 + @ ;
+
 \ Store a null-terminated UTF-16 string HERE, and return a pointer to its buffer
 \ at runtime.
 : UTF16"
@@ -14,4 +26,15 @@
   0 C, 0 C, \ Null terminator
   ;
 
-UTF16" Hello UEFI!" ConOut.OutputString()
+  BootServices.LocateProtocol(GOP) \ *This
+  HERE @ 255 C, 0 C, 0 C, 0 C, \ *BltBuffer = single blue pixel
+  0 \ BltOperation = EfiBltVideoFill
+  0 \ SourceX
+  0 \ SourceY
+  100 \ DestinationX
+  200 \ DestinationY
+  400 \ Width
+  20 \ Height
+  0 \ Delta (unused)
+GOP.Blt EFICALL10
+.U NEWLINE
-- 
2.39.2