x86: add freestanding port

README.md

@@ -26,7 +26,7 @@ Adding support for new architectures is easy, but you need to know assembly lang
 |     ppc64    | ✓             | ✓       |                       |
 |    riscv64   | ✓             |         |                       |
 |     s390x    | ✓             |         |                       |
-|      x86     | ✓             |         |                       |
+|      x86     | ✓             |         | ✓                     |
 |    x86_64    | ✓             |         | ✓                     |
 
 

arch/x86/freestanding/bits.h

@@ -0,0 +1,48 @@
+#ifndef LIBUCONTEXT_BITS_H
+#define LIBUCONTEXT_BITS_H
+
+#define REG_GS		(0)
+#define REG_FS		(1)
+#define REG_ES		(2)
+#define REG_DS		(3)
+#define REG_EDI		(4)
+#define REG_ESI		(5)
+#define REG_EBP		(6)
+#define REG_ESP		(7)
+#define REG_EBX		(8)
+#define REG_EDX		(9)
+#define REG_ECX		(10)
+#define REG_EAX		(11)
+#define REG_EIP		(14)
+
+typedef int libucontext_greg_t, libucontext_gregset_t[19];
+
+typedef struct libucontext_fpstate {
+	unsigned long cw, sw, tag, ipoff, cssel, dataoff, datasel;
+	struct {
+		unsigned short significand[4], exponent;
+	} _st[8];
+	unsigned long status;
+} *libucontext_fpregset_t;
+
+typedef struct {
+	libucontext_gregset_t gregs;
+	libucontext_fpregset_t fpregs;
+	unsigned long oldmask, cr2;
+} libucontext_mcontext_t;
+
+typedef struct {
+	void *ss_sp;
+	int ss_flags;
+	size_t ss_size;
+} libucontext_stack_t;
+
+typedef struct libucontext_ucontext {
+	unsigned long uc_flags;
+	struct libucontext_ucontext *uc_link;
+	libucontext_stack_t uc_stack;
+	libucontext_mcontext_t uc_mcontext;
+} libucontext_ucontext_t;
+
+#endif
+