1 files changed, 89 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/com32/lib/pci/cfgtype.c b/contrib/syslinux-4.02/com32/lib/pci/cfgtype.c
new file mode 100644
index 0000000..896f7e5
--- /dev/null
+++ b/contrib/syslinux-4.02/com32/lib/pci/cfgtype.c
@@ -0,0 +1,89 @@
+#include "pci/pci.h"
+#include <com32.h>
+#include <string.h>
+
+enum pci_config_type __pci_cfg_type;
+
+static int type1_ok(void)
+{
+    uint32_t oldcf8, newcf8;
+
+    /* Test for Configuration Method #1 */
+
+    /* Note: XFree86 writes ~0 and expects to read back 0x80fffffc.  Linux
+       does this less severe test; go with Linux. */
+
+    cli();
+    outb(1, 0xcfb);		/* For old Intel chipsets */
+    oldcf8 = inl(0xcf8);
+    outl(0x80000000, 0xcf8);
+    newcf8 = inl(0xcf8);
+    outl(oldcf8, 0xcf8);
+    sti();
+
+    return newcf8 == 0x80000000;
+}
+
+static int type2_ok(void)
+{
+    uint8_t oldcf8, oldcfa;
+    uint8_t cf8, cfa;
+
+    /* Test for Configuration Method #2 */
+
+    /* CM#2 is hard to probe for, but let's do our best... */
+
+    cli();
+    outb(0, 0xcfb);		/* For old Intel chipsets */
+    oldcf8 = inb(0xcf8);
+    outb(0, 0xcf8);
+    oldcfa = inb(0xcfa);
+    outb(0, 0xcfa);
+
+    cf8 = inb(0xcf8);
+    cfa = inb(0xcfa);
+
+    outb(oldcf8, 0xcf8);
+    outb(oldcfa, 0xcfa);
+    sti();
+
+    return cf8 == 0 && cfa == 0;
+}
+
+int pci_set_config_type(enum pci_config_type type)
+{
+    static const com32sys_t ireg = {
+	.eax.l = 0xb101,
+	.edi.l = 0,
+	.eflags.l = EFLAGS_CF,
+    };
+    com32sys_t oreg;
+
+    if (type == PCI_CFG_AUTO) {
+	type = PCI_CFG_NONE;
+
+	/* Try to detect PCI BIOS */
+	__intcall(0x1a, &ireg, &oreg);
+
+	if (!(oreg.eflags.l & EFLAGS_CF) &&
+	    oreg.eax.b[1] == 0 && oreg.edx.l == 0x20494250) {
+	    /* PCI BIOS present.  Use direct access if we know how to do it. */
+
+	    if ((oreg.eax.b[0] & 1) && type1_ok())
+		type = PCI_CFG_TYPE1;
+	    else if ((oreg.eax.b[0] & 2) && type2_ok())
+		type = PCI_CFG_TYPE2;
+	    else
+		type = PCI_CFG_BIOS;	/* Use BIOS calls as fallback */
+
+	} else if (type1_ok()) {
+	    type = PCI_CFG_TYPE1;
+	} else if (type2_ok()) {
+	    type = PCI_CFG_TYPE2;
+	} else {
+	    type = PCI_CFG_NONE;	/* Badness... */
+	}
+    }
+
+    return (__pci_cfg_type = type);
+}