xref: /openbmc/linux/arch/microblaze/include/asm/flat.h (revision e2c75e76)
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 int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
36 					u32 *addr, u32 *persistent)
37 {
38 	u32 *p = (__force u32 *)rp;
39 
40 	/* Is it a split 64/32 reference? */
41 	if (relval & 0x80000000) {
42 		/* Grab the two halves of the reference */
43 		u32 val_hi, val_lo;
44 
45 		val_hi = get_unaligned(p);
46 		val_lo = get_unaligned(p+1);
47 
48 		/* Crack the address out */
49 		*addr = ((val_hi & 0xffff) << 16) + (val_lo & 0xffff);
50 	} else {
51 		/* Get the address straight out */
52 		*addr = get_unaligned(p);
53 	}
54 
55 	return 0;
56 }
57 
58 /*
59  * Insert an address into the symbol reference at rp. rp is potentially
60  * unaligned.
61  */
62 
63 static inline int
64 flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 relval)
65 {
66 	u32 *p = (__force u32 *)rp;
67 	/* Is this a split 64/32 reloc? */
68 	if (relval & 0x80000000) {
69 		/* Get the two "halves" */
70 		unsigned long val_hi = get_unaligned(p);
71 		unsigned long val_lo = get_unaligned(p + 1);
72 
73 		/* insert the address */
74 		val_hi = (val_hi & 0xffff0000) | addr >> 16;
75 		val_lo = (val_lo & 0xffff0000) | (addr & 0xffff);
76 
77 		/* store the two halves back into memory */
78 		put_unaligned(val_hi, p);
79 		put_unaligned(val_lo, p+1);
80 	} else {
81 		/* Put it straight in, no messing around */
82 		put_unaligned(addr, p);
83 	}
84 	return 0;
85 }
86 
87 #define	flat_get_relocate_addr(rel)	(rel & 0x7fffffff)
88 
89 #endif /* _ASM_MICROBLAZE_FLAT_H */
90