add basic drawing functions

.gitignore

@@ -1 +1,3 @@
-build/
+build/
+.cache/
+compile_commands.json

README.md

@@ -0,0 +1,5 @@
+Arch uefi_run fix: sudo ln -s /usr/share/edk2/x64/OVMF_CODE.4m.fd /usr/share/qemu/OVMF.fd
+
+cd  edk2
+source edksetup.sh
+make -C BaseTools # if first run

UEFI_fireworks.dsc

@@ -22,6 +22,9 @@ PrintLib|edk2/MdePkg/Library/BasePrintLib/BasePrintLib.inf
 PcdLib|edk2/MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
 RegisterFilterLib|edk2/MdePkg/Library/RegisterFilterLibNull/RegisterFilterLibNull.inf
 StackCheckLib|edk2/MdePkg/Library/StackCheckLibNull/StackCheckLibNull.inf
+TimerLib|edk2/MdePkg/Library/SecPeiDxeTimerLibCpu/SecPeiDxeTimerLibCpu.inf
+IoLib|edk2/MdePkg/Library/BaseIoLibIntrinsic/BaseIoLibIntrinsic.inf
+
 
 
 [Components]

build.sh

@@ -2,4 +2,4 @@
 export PACKAGES_PATH=$PWD:$PWD/edk2
 build -a X64 -t GCC5 -p UEFI_fireworks.dsc
 mkdir -p build
-cp edk2/Build/UEFI_fireworks/DEBUG_GCC5/X64/UEFI_fireworks.efi build/
+cp edk2/Build/UEFI_fireworks/DEBUG_GCC5/X64/UEFI_fireworks.efi build/

src/UEFI_fireworks/UEFI_fireworks.inf

@@ -8,6 +8,7 @@
 
 [Sources]
   UefiMain.c
+  drawing.c
 
 [Packages]
   edk2/MdePkg/MdePkg.dec
@@ -23,6 +24,7 @@
   UefiRuntimeServicesTableLib
   DebugLib
   PrintLib
+  TimerLib
 
 [Protocols]
 

src/UEFI_fireworks/UefiMain.c

@@ -1,7 +1,14 @@
+#include "drawing.h"
+#include "global.h"
+#include <Base.h>
 #include <Library/UefiBootServicesTableLib.h>
 #include <Library/UefiLib.h>
+#include <Protocol/GraphicsOutput.h>
 #include <Uefi.h>
 
+EFI_GRAPHICS_OUTPUT_PROTOCOL *GraphicsOutput = NULL;
+EFI_GRAPHICS_OUTPUT_BLT_PIXEL *framebuffer = NULL;
+
 EFI_STATUS EFIAPI UefiMain(IN EFI_HANDLE imgHandle,
                            IN EFI_SYSTEM_TABLE *sysTable) {
   gST = sysTable;
@@ -11,18 +18,19 @@ EFI_STATUS EFIAPI UefiMain(IN EFI_HANDLE imgHandle,
   // UEFI apps automatically exit after 5 minutes. Stop that here
   gBS->SetWatchdogTimer(0, 0, 0, NULL);
 
-  Print(L"Hello, world!\r\n");
+  // get screen size
+  UINTN Columns;
+  UINTN Rows;
 
-  // Allocate a string
+  gST->ConOut->QueryMode(gST->ConOut, gST->ConOut->Mode->Mode, &Columns, &Rows);
-  CHAR16 *str = NULL;
-  gBS->AllocatePool(EfiLoaderData, 36, (VOID **)&str);
 
-  // Copy over a string
+  gBS->LocateProtocol(&gEfiGraphicsOutputProtocolGuid, NULL,
-  CHAR16 *str2 = L"Allocated string\r\n";
+                      (VOID **)&GraphicsOutput);
-  gBS->CopyMem((VOID *)str, (VOID *)str2, 36);
 
-  Print(str);
+  framebuffer =
-  gBS->FreePool(str);
+      (EFI_GRAPHICS_OUTPUT_BLT_PIXEL *)GraphicsOutput->Mode->FrameBufferBase;
+
+  clear_screen(GraphicsOutput);
 
   return EFI_SUCCESS;
 }

src/UEFI_fireworks/const.h

@@ -0,0 +1,6 @@
+#pragma once
+#include "macros.h"
+#include <Protocol/GraphicsOutput.h>
+
+EFI_GRAPHICS_OUTPUT_BLT_PIXEL night_sky =
+    COLOR_FROM_HEX(0x11095e); // this cannot be const becose EDK2 said so

src/UEFI_fireworks/drawing.c

@@ -0,0 +1,80 @@
+#include "Library/UefiLib.h"
+#include "ProcessorBind.h"
+#include "const.h"
+#include "global.h"
+#include "macros.h"
+#include <Library/UefiApplicationEntryPoint.h>
+#include <Protocol/GraphicsOutput.h>
+
+void draw_pixel(const UINT32 x, const UINT32 y,
+                const EFI_GRAPHICS_OUTPUT_BLT_PIXEL pixel) {
+  UINTN framebuffer_offset =
+      (y * GraphicsOutput->Mode->Info->PixelsPerScanLine) + x;
+  if (framebuffer_offset >= GraphicsOutput->Mode->FrameBufferSize) {
+    Print(L"Atepted out of bounds write to framebuffer\r\n");
+    Exit(RETURN_WARN_BUFFER_TOO_SMALL);
+  }
+
+  framebuffer[framebuffer_offset] = pixel;
+}
+
+// uses Mid-Point Circle Drawing Algorithm
+// inspired by
+// https://www.geeksforgeeks.org/dsa/mid-point-circle-drawing-algorithm/
+void draw_circle(int xc, int yc, int r,
+                 const EFI_GRAPHICS_OUTPUT_BLT_PIXEL color) {
+  int x = r, y = 0;
+  draw_pixel(x + xc, y + yc, color);
+
+  if (r > 0) {
+    draw_pixel(x + xc, -y + yc, color);
+    draw_pixel(y + xc, x + yc, color);
+    draw_pixel(-y + xc, x + yc, color);
+  }
+
+  int P = 1 - r;
+  while (x > y) {
+    y++;
+
+    if (P <= 0)
+      P = P + 2 * y + 1;
+
+    else {
+      x--;
+      P = P + 2 * y - 2 * x + 1;
+    }
+
+    if (x < y)
+      break;
+
+    draw_pixel(x + xc, y + yc, color);
+    draw_pixel(-x + xc, y + yc, color);
+    draw_pixel(x + xc, -y + yc, color);
+    draw_pixel(-x + xc, -y + yc, color);
+
+    if (x != y) {
+      draw_pixel(y + xc, x + yc, color);
+      draw_pixel(-y + xc, x + yc, color);
+      draw_pixel(y + xc, -x + yc, color);
+      draw_pixel(-y + xc, -x + yc, color);
+    }
+  }
+}
+
+void clear_screen() {
+  // fill screen
+  if (GraphicsOutput != NULL) {
+    GraphicsOutput->Blt(
+        GraphicsOutput,
+        &night_sky,                                       // BltBuffer
+        EfiBltVideoFill,                                  // BltOperation
+        0,                                                // SourceX
+        0,                                                // SourceY
+        0,                                                // DestinationX
+        0,                                                // DestinationY
+        GraphicsOutput->Mode->Info->HorizontalResolution, // Width
+        GraphicsOutput->Mode->Info->VerticalResolution,   // Height
+        0 // Delta (not used for fill operations)
+    );
+  }
+}

src/UEFI_fireworks/drawing.h

@@ -0,0 +1,5 @@
+#pragma once
+#include <Protocol/GraphicsOutput.h>
+void draw_circle(int xc, int yc, int r,
+                 const EFI_GRAPHICS_OUTPUT_BLT_PIXEL color);
+void clear_screen(EFI_GRAPHICS_OUTPUT_PROTOCOL *GraphicsOutput);

src/UEFI_fireworks/global.h

@@ -0,0 +1,4 @@
+#pragma once
+#include <Protocol/GraphicsOutput.h>
+extern EFI_GRAPHICS_OUTPUT_PROTOCOL *GraphicsOutput;
+extern EFI_GRAPHICS_OUTPUT_BLT_PIXEL *framebuffer;

src/UEFI_fireworks/macros.h

@@ -0,0 +1,6 @@
+#pragma once
+#define COLOR_FROM_HEX(hex)                                                    \
+  {.Blue = (hex) & 0xFF,                                                       \
+   .Green = ((hex) >> 8) & 0xFF,                                               \
+   .Red = ((hex) >> 16) & 0xFF,                                                \
+   .Reserved = 0}

test.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+cp /usr/share/edk2/x64/OVMF_VARS.4m.fd ./my_ovmf_vars.fd
+
+qemu-system-x86_64 \
+  -machine type=q35,accel=kvm \
+  -drive if=pflash,format=raw,readonly=on,file=/usr/share/edk2/x64/OVMF_CODE.4m.fd \
+  -drive if=pflash,format=raw,file=./my_ovmf_vars.fd \
+  -hda fat:rw:$(dirname build/UEFI_fireworks.efi)
+rm ./my_ovmf_vars.fd