[FREELDR] Support a "video=..." command-line option; use it in pcvideo.c (reactos#8529)

This command-line option can be used when chainloading freeldr.sys from
another bootloader. In this case, pcvideo.c uses this option to set an
initial display mode.

settings.c: Simplify also parsing the separate options from the command-line.

Author: HBelusca

boot/freeldr/freeldr/arch/i386/pc/pcvideo.c

@@ -1025,59 +1025,70 @@ PcVideoInit(VOID)
     /* Retrieve the initial display mode parameters */
     PcVideoGetDisplayMode();
 
+    /* If any video options have been specified, try to set a display mode */
+    if (BootMgrInfo.VideoOptions && *BootMgrInfo.VideoOptions)
+        PcVideoSetDisplayMode(BootMgrInfo.VideoOptions, TRUE);
+
     // FIXME: We don't support graphics modes yet!
     // Revert to 80x25 text mode.
     if (DisplayMode != VideoTextMode)
         PcVideoSetMode(VIDEOMODE_NORMAL_TEXT);
 }
 
+#define TRACE_printf(Format, ...) \
+do { \
+    TRACE(Format, ##__VA_ARGS__); \
+    printf(Format, ##__VA_ARGS__); \
+} while (0)
+
 VIDEODISPLAYMODE
 PcVideoSetDisplayMode(PCSTR DisplayModeName, BOOLEAN Init)
 {
     USHORT VideoMode = VIDEOMODE_NORMAL_TEXT;
 
     if (!DisplayModeName || *DisplayModeName == '\0')
-    {
-        PcVideoSetBlinkBit(!Init);
-        return DisplayMode;
-    }
+        goto Quit;
 
     if (VideoCard == VIDEOCARD_CGA_OR_OTHER)
     {
-        TRACE("CGA or other display adapter detected.\n");
-        printf("CGA or other display adapter detected.\n");
-        printf("Using 80x25 text mode.\n");
+        TRACE_printf("CGA or other display adapter detected.\n");
+        TRACE_printf("Using 80x25 text mode.\n");
         VideoMode = VIDEOMODE_NORMAL_TEXT;
     }
     else if (VideoCard == VIDEOCARD_EGA)
     {
-        TRACE("EGA display adapter detected.\n");
-        printf("EGA display adapter detected.\n");
-        printf("Using 80x25 text mode.\n");
+        TRACE_printf("EGA display adapter detected.\n");
+        TRACE_printf("Using 80x25 text mode.\n");
         VideoMode = VIDEOMODE_NORMAL_TEXT;
     }
     else /* VIDEOCARD_VGA */
     {
-        TRACE("VGA display adapter detected.\n");
+        TRACE_printf("VGA display adapter detected.\n");
+
+        /* Get the video option separator, if any */
+        size_t NameLen = strcspn(DisplayModeName, ",");
+        if (!NameLen)
+            goto Quit;
 
-        if (_stricmp(DisplayModeName, "NORMAL_VGA") == 0)
+        if (_strnicmp(DisplayModeName, "NORMAL_VGA", NameLen) == 0)
             VideoMode = VIDEOMODE_NORMAL_TEXT;
-        else if (_stricmp(DisplayModeName, "EXTENDED_VGA") == 0)
+        else if (_strnicmp(DisplayModeName, "EXTENDED_VGA", NameLen) == 0)
             VideoMode = VIDEOMODE_EXTENDED_TEXT;
         else
             VideoMode = (USHORT)strtoul(DisplayModeName, NULL, 0);
     }
 
     if (!PcVideoSetMode(VideoMode))
     {
-        printf("Error: unable to set video display mode 0x%x\n", (int)VideoMode);
-        printf("Defaulting to 80x25 text mode.\n");
+        TRACE_printf("Error: unable to set video display mode 0x%x\n", VideoMode);
+        TRACE_printf("Defaulting to 80x25 text mode.\n");
         printf("Press any key to continue.\n");
         PcConsGetCh();
 
         PcVideoSetMode(VIDEOMODE_NORMAL_TEXT);
     }
 
+Quit:
     PcVideoSetBlinkBit(!Init);
     return DisplayMode;
 }

boot/freeldr/freeldr/include/settings.h

@@ -10,6 +10,7 @@
 typedef struct _BOOTMGRINFO
 {
     PCSTR DebugString;
+    PCSTR VideoOptions;
     PCSTR DefaultOs;
     LONG  TimeOut;
     ULONG_PTR FrLdrSection;

boot/freeldr/freeldr/settings.c

@@ -14,17 +14,19 @@
 /* GLOBALS ********************************************************************/
 
 static CCHAR DebugString[256];
+static CCHAR VideoOptions[256];
 static CCHAR DefaultOs[256];
-BOOTMGRINFO BootMgrInfo = {NULL, NULL, -1, 0};
+BOOTMGRINFO BootMgrInfo = {NULL, NULL, NULL, -1, 0};
 
 /* FUNCTIONS ******************************************************************/
 
 static VOID
 CmdLineParse(
     _In_ PCSTR CmdLine)
 {
-    PCHAR End, Setting;
-    ULONG_PTR Length, Offset = 0;
+    PCHAR Setting;
+    size_t Length;
+    ULONG_PTR Offset = 0;
 
     /*
      * Get the debug string, in the following format:
@@ -37,8 +39,7 @@ CmdLineParse(
     {
         /* Check if there are more command-line parameters following */
         Setting += sizeof("debug=") - sizeof(ANSI_NULL);
-        End = strstr(Setting, " ");
-        Length = (End ? (End - Setting) : strlen(Setting));
+        Length = strcspn(Setting, " \t");
 
         /* Copy the debug string and upcase it */
         RtlStringCbCopyNA(DebugString, sizeof(DebugString), Setting, Length);
@@ -55,6 +56,30 @@ CmdLineParse(
         BootMgrInfo.DebugString = DebugString;
     }
 
+    /* Get the video options */
+    Setting = strstr(CmdLine, "video=");
+    if (Setting)
+    {
+        Setting += sizeof("video=") - sizeof(ANSI_NULL);
+    }
+#if (defined(_M_IX86) || defined(_M_AMD64)) && !defined(SARCH_XBOX) && !defined(SARCH_PC98)
+    else
+    {
+        Setting = strstr(CmdLine, "vga=");
+        if (Setting)
+            Setting += sizeof("vga=") - sizeof(ANSI_NULL);
+    }
+#endif
+    if (Setting)
+    {
+        /* Check if there are more command-line parameters following */
+        Length = strcspn(Setting, " \t");
+
+        /* Copy the string */
+        RtlStringCbCopyNA(VideoOptions, sizeof(VideoOptions), Setting, Length);
+        BootMgrInfo.VideoOptions = VideoOptions;
+    }
+
     /* Get the timeout */
     Setting = strstr(CmdLine, "timeout=");
     if (Setting)
@@ -69,8 +94,7 @@ CmdLineParse(
     {
         /* Check if there are more command-line parameters following */
         Setting += sizeof("defaultos=") - sizeof(ANSI_NULL);
-        End = strstr(Setting, " ");
-        Length = (End ? (End - Setting) : strlen(Setting));
+        Length = strcspn(Setting, " \t");
 
         /* Copy the default OS */
         RtlStringCbCopyNA(DefaultOs, sizeof(DefaultOs), Setting, Length);