Changeset 82278 in vbox

Timestamp:

Nov 28, 2019 9:23:32 PM (5 years ago)

Author:

vboxsync

Message:

VGABIOS: Use inlines instead of calls for far memory access. Saves over 700 bytes of code.

Location:

trunk/src/VBox/Devices/Graphics/BIOS

Files:

• inlines.h (modified) (1 diff)
• vgabios.c (modified) (5 diffs)

trunk/src/VBox/Devices/Graphics/BIOS/inlines.h

@@ -31 +31 @@
 #define outw(p, v)  outpw(p, v)
 
-extern  uint8_t     read_byte(uint16_t seg, uint16_t offset);
-extern  uint16_t    read_word(uint16_t seg, uint16_t offset);
-extern  uint32_t    read_dword(uint16_t seg, uint16_t offset);
-extern  void        write_byte(uint16_t seg, uint16_t offset, uint8_t data);
-extern  void        write_word(uint16_t seg, uint16_t offset, uint16_t data);
-extern  void        write_dword(uint16_t seg, uint16_t offset, uint32_t data);
+/* Far byte/word/dword access routines. */
+
+inline uint8_t read_byte(uint16_t seg, uint16_t offset)
+{
+    return( *(seg:>(uint8_t *)offset) );
+}
+
+inline void write_byte(uint16_t seg, uint16_t offset, uint8_t data)
+{
+    *(seg:>(uint8_t *)offset) = data;
+}
+
+inline uint16_t read_word(uint16_t seg, uint16_t offset)
+{
+    return( *(seg:>(uint16_t *)offset) );
+}
+
+inline void write_word(uint16_t seg, uint16_t offset, uint16_t data)
+{
+    *(seg:>(uint16_t *)offset) = data;
+}
+
+inline uint32_t read_dword(uint16_t seg, uint16_t offset)
+{
+    return( *(seg:>(uint32_t *)offset) );
+}
+
+inline void write_dword(uint16_t seg, uint16_t offset, uint32_t data)
+{
+    *(seg:>(uint32_t *)offset) = data;
+}
 
 void int_enable(void);

trunk/src/VBox/Devices/Graphics/BIOS/vgabios.c

@@ -78 +78 @@
 static uint8_t find_vga_entry();
 
+extern uint8_t xread_byte(uint16_t seg, uint16_t offset);
+
 #ifdef VBE
 extern uint16_t __cdecl vbe_has_vbe_display(void);
@@ -1391 +1393 @@
      mask=0x80>>j;
      outw(VGAREG_GRDC_ADDRESS, (mask << 8) | 0x08);
-     read_byte(0xa000,dest);
+     xread_byte(0xa000,dest);
      if(fdata[src+i]&mask)
       {
@@ -1638 +1640 @@
      outw(VGAREG_GRDC_ADDRESS, (mask << 8) | 0x08);
      outw(VGAREG_GRDC_ADDRESS, 0x0205);
-     data = read_byte(0xa000,addr);
+     data = xread_byte(0xa000,addr);
      if (AL & 0x80)
       {
@@ -2325 +2327 @@
 /* =========================================================== */
 
-uint8_t read_byte(uint16_t seg, uint16_t offset)
+/* This function is used for planar VGA memory reads to defeat the
+ * optimizer. We must read exactly one byte, otherwise the screen
+ * may be corrupted.
+ */
+uint8_t xread_byte(uint16_t seg, uint16_t offset)
 {
     return( *(seg:>(uint8_t *)offset) );
-}
-
-void write_byte(uint16_t seg, uint16_t offset, uint8_t data)
-{
-    *(seg:>(uint8_t *)offset) = data;
-}
-
-uint16_t read_word(uint16_t seg, uint16_t offset)
-{
-    return( *(seg:>(uint16_t *)offset) );
-}
-
-void write_word(uint16_t seg, uint16_t offset, uint16_t data)
-{
-    *(seg:>(uint16_t *)offset) = data;
-}
-
-uint32_t read_dword(uint16_t seg, uint16_t offset)
-{
-    return( *(seg:>(uint32_t *)offset) );
-}
-
-void write_dword(uint16_t seg, uint16_t offset, uint32_t data)
-{
-    *(seg:>(uint32_t *)offset) = data;
 }
 
@@ -2566 +2547 @@
         if (GET_AL() < 2) {
             write_byte(BIOSMEM_SEG,BIOSMEM_VIDEO_CTL,
-              (read_byte(BIOSMEM_SEG,BIOSMEM_VIDEO_CTL) & ~1) | GET_AL());
+              (xread_byte(BIOSMEM_SEG,BIOSMEM_VIDEO_CTL) & ~1) | GET_AL());
             SET_AL(0x12);
         }