initial version

Book-Lite/linux-0.12/kernel/math/ea.c

@@ -0,0 +1,92 @@
+/*
+ * linux/kernel/math/ea.c
+ *
+ * (C) 1991 Linus Torvalds
+ */
+
+/*
+ * Calculate the effective address.
+ */
+
+#include <stddef.h>
+
+#include <linux/math_emu.h>
+#include <asm/segment.h>
+
+static int __regoffset[] = {
+	offsetof(struct info,___eax),
+	offsetof(struct info,___ecx),
+	offsetof(struct info,___edx),
+	offsetof(struct info,___ebx),
+	offsetof(struct info,___esp),
+	offsetof(struct info,___ebp),
+	offsetof(struct info,___esi),
+	offsetof(struct info,___edi)
+};
+
+#define REG(x) (*(long *)(__regoffset[(x)]+(char *) info))
+
+static char * sib(struct info * info, int mod)
+{
+	unsigned char ss,index,base;
+	long offset = 0;
+
+	base = get_fs_byte((char *) EIP);
+	EIP++;
+	ss = base >> 6;
+	index = (base >> 3) & 7;
+	base &= 7;
+	if (index == 4)
+		offset = 0;
+	else
+		offset = REG(index);
+	offset <<= ss;
+	if (mod || base != 5)
+		offset += REG(base);
+	if (mod == 1) {
+		offset += (signed char) get_fs_byte((char *) EIP);
+		EIP++;
+	} else if (mod == 2 || base == 5) {
+		offset += (signed) get_fs_long((unsigned long *) EIP);
+		EIP += 4;
+	}
+	I387.foo = offset;
+	I387.fos = 0x17;
+	return (char *) offset;
+}
+
+char * ea(struct info * info, unsigned short code)
+{
+	unsigned char mod,rm;
+	long * tmp = &EAX;
+	int offset = 0;
+
+	mod = (code >> 6) & 3;
+	rm = code & 7;
+	if (rm == 4 && mod != 3)
+		return sib(info,mod);
+	if (rm == 5 && !mod) {
+		offset = get_fs_long((unsigned long *) EIP);
+		EIP += 4;
+		I387.foo = offset;
+		I387.fos = 0x17;
+		return (char *) offset;
+	}
+	tmp = & REG(rm);
+	switch (mod) {
+		case 0: offset = 0; break;
+		case 1:
+			offset = (signed char) get_fs_byte((char *) EIP);
+			EIP++;
+			break;
+		case 2:
+			offset = (signed) get_fs_long((unsigned long *) EIP);
+			EIP += 4;
+			break;
+		case 3:
+			math_abort(info,1<<(SIGILL-1));
+	}
+	I387.foo = offset;
+	I387.fos = 0x17;
+	return offset + (char *) *tmp;
+}