xref: /openbmc/linux/arch/microblaze/include/asm/flat.h (revision a09d2831)
1 /*
2  * uClinux flat-format executables
3  *
4  * Copyright (C) 2005 John Williams <jwilliams@itee.uq.edu.au>
5  *
6  * This file is subject to the terms and conditions of the GNU General
7  * Public License. See the file COPYING in the main directory of this
8  * archive for more details.
9  */
10 
11 #ifndef _ASM_MICROBLAZE_FLAT_H
12 #define _ASM_MICROBLAZE_FLAT_H
13 
14 #include <asm/unaligned.h>
15 
16 #define	flat_argvp_envp_on_stack()	0
17 #define	flat_old_ram_flag(flags)	(flags)
18 #define	flat_reloc_valid(reloc, size)	((reloc) <= (size))
19 #define	flat_set_persistent(relval, p)		0
20 
21 /*
22  * Microblaze works a little differently from other arches, because
23  * of the MICROBLAZE_64 reloc type. Here, a 32 bit address is split
24  * over two instructions, an 'imm' instruction which provides the top
25  * 16 bits, then the instruction "proper" which provides the low 16
26  * bits.
27  */
28 
29 /*
30  * Crack open a symbol reference and extract the address to be
31  * relocated. rp is a potentially unaligned pointer to the
32  * reference
33  */
34 
35 static inline unsigned long
36 flat_get_addr_from_rp(unsigned long *rp, unsigned long relval,
37 			unsigned long flags, unsigned long *persistent)
38 {
39 	unsigned long addr;
40 	(void)flags;
41 
42 	/* Is it a split 64/32 reference? */
43 	if (relval & 0x80000000) {
44 		/* Grab the two halves of the reference */
45 		unsigned long val_hi, val_lo;
46 
47 		val_hi = get_unaligned(rp);
48 		val_lo = get_unaligned(rp+1);
49 
50 		/* Crack the address out */
51 		addr = ((val_hi & 0xffff) << 16) + (val_lo & 0xffff);
52 	} else {
53 		/* Get the address straight out */
54 		addr = get_unaligned(rp);
55 	}
56 
57 	return addr;
58 }
59 
60 /*
61  * Insert an address into the symbol reference at rp. rp is potentially
62  * unaligned.
63  */
64 
65 static inline void
66 flat_put_addr_at_rp(unsigned long *rp, unsigned long addr, unsigned long relval)
67 {
68 	/* Is this a split 64/32 reloc? */
69 	if (relval & 0x80000000) {
70 		/* Get the two "halves" */
71 		unsigned long val_hi = get_unaligned(rp);
72 		unsigned long val_lo = get_unaligned(rp + 1);
73 
74 		/* insert the address */
75 		val_hi = (val_hi & 0xffff0000) | addr >> 16;
76 		val_lo = (val_lo & 0xffff0000) | (addr & 0xffff);
77 
78 		/* store the two halves back into memory */
79 		put_unaligned(val_hi, rp);
80 		put_unaligned(val_lo, rp+1);
81 	} else {
82 		/* Put it straight in, no messing around */
83 		put_unaligned(addr, rp);
84 	}
85 }
86 
87 #define	flat_get_relocate_addr(rel)	(rel & 0x7fffffff)
88 
89 #endif /* _ASM_MICROBLAZE_FLAT_H */
90