imported SEABIOS source tree

[palacios.git] / bios / seabios / src / bregs.h

diff --git a/bios/seabios/src/bregs.h b/bios/seabios/src/bregs.h
new file mode 100644 (file)
index 0000000..f026fa8
--- /dev/null
+++ b/bios/seabios/src/bregs.h
@@ -0,0 +1,96 @@
+// Structure layout of cpu registers the the bios uses.
+//
+// Copyright (C) 2008  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU LGPLv3 license.
+
+#ifndef __BREGS_H
+#define __BREGS_H
+
+// CPU flag bitdefs
+#define F_CF (1<<0)
+#define F_ZF (1<<6)
+#define F_IF (1<<9)
+
+// CR0 flags
+#define CR0_PG (1<<31) // Paging
+#define CR0_CD (1<<30) // Cache disable
+#define CR0_NW (1<<29) // Not Write-through
+#define CR0_PE (1<<0)  // Protection enable
+
+
+#ifndef __ASSEMBLY__
+
+#include "farptr.h" // struct segoff_s
+
+/****************************************************************
+ * Registers saved/restored in romlayout.S
+ ****************************************************************/
+
+#include "types.h" // u16
+
+#define UREG(ER, R, RH, RL) union { u32 ER; struct { u16 R; u16 R ## _hi; }; struct { u8 RL; u8 RH; u8 R ## _hilo; u8 R ## _hihi; }; }
+
+// Layout of registers passed in to irq handlers.  Note that this
+// layout corresponds to code in romlayout.S - don't change it here
+// without also updating the assembler code.
+struct bregs {
+    u16 ds;
+    u16 es;
+    UREG(edi, di, di8u, di8l);
+    UREG(esi, si, si8u, si8l);
+    UREG(ebp, bp, bp8u, bp8l);
+    UREG(ebx, bx, bh, bl);
+    UREG(edx, dx, dh, dl);
+    UREG(ecx, cx, ch, cl);
+    UREG(eax, ax, ah, al);
+    struct segoff_s code;
+    u16 flags;
+} PACKED;
+
+
+/****************************************************************
+ * Helper functions
+ ****************************************************************/
+
+static inline void
+set_cf(struct bregs *regs, int cond)
+{
+    if (cond)
+        regs->flags |= F_CF;
+    else
+        regs->flags &= ~F_CF;
+}
+
+// Frequently used return codes
+#define RET_EUNSUPPORTED 0x86
+
+static inline void
+set_success(struct bregs *regs)
+{
+    set_cf(regs, 0);
+}
+
+static inline void
+set_code_success(struct bregs *regs)
+{
+    regs->ah = 0;
+    set_cf(regs, 0);
+}
+
+static inline void
+set_invalid_silent(struct bregs *regs)
+{
+    set_cf(regs, 1);
+}
+
+static inline void
+set_code_invalid_silent(struct bregs *regs, u8 code)
+{
+    regs->ah = code;
+    set_cf(regs, 1);
+}
+
+#endif // !__ASSEMBLY__
+
+#endif // bregs.h