diff options
Diffstat (limited to 'include/elf')
| -rw-r--r-- | include/elf/ChangeLog | 6 | ||||
| -rw-r--r-- | include/elf/ppc64.h | 47 |
2 files changed, 53 insertions, 0 deletions
diff --git a/include/elf/ChangeLog b/include/elf/ChangeLog index 2999bc8..7e98ddb 100644 --- a/include/elf/ChangeLog +++ b/include/elf/ChangeLog @@ -1,5 +1,11 @@ 2013-10-30 Alan Modra <amodra@gmail.com> + * ppc64.h (STO_PPC64_LOCAL_BIT, STO_PPC64_LOCAL_MASK): Define. + (ppc64_decode_local_entry, ppc64_encode_local_entry): New functions. + (PPC64_LOCAL_ENTRY_OFFSET, PPC64_SET_LOCAL_ENTRY_OFFSET): Define. + +2013-10-30 Alan Modra <amodra@gmail.com> + * ppc64.h (EF_PPC64_ABI): Define. 2013-10-30 Alan Modra <amodra@gmail.com> diff --git a/include/elf/ppc64.h b/include/elf/ppc64.h index 1121649..d3cfdfb 100644 --- a/include/elf/ppc64.h +++ b/include/elf/ppc64.h @@ -180,6 +180,53 @@ END_RELOC_NUMBERS (R_PPC64_max) 0 for unspecified or not using any features affected by the differences. */ #define EF_PPC64_ABI 3 +/* The ELFv2 ABI uses three bits in the symbol st_other field of a + function definition to specify the number of instructions between a + function's global entry point and local entry point. + The global entry point is used when it is necessary to set up the + toc pointer (r2) for the function. Callers must enter the global + entry point with r12 set to the global entry point address. On + return from the function, r2 may have a different value to that + which it had on entry. + The local entry point is used when r2 is known to already be valid + for the function. There is no requirement on r12 when using the + local entry point, and on return r2 will contain the same value as + at entry. + A value of zero in these bits means that the function has a single + entry point with no requirement on r12 or r2, and that on return r2 + will contain the same value as at entry. + Values of one and seven are reserved. */ +#define STO_PPC64_LOCAL_BIT 5 +#define STO_PPC64_LOCAL_MASK (7 << STO_PPC64_LOCAL_BIT) + +// 3 bit other field to bytes. +static inline unsigned int +ppc64_decode_local_entry(unsigned int other) +{ + return ((1 << other) >> 2) << 2; +} + +// bytes to field value. +static inline unsigned int +ppc64_encode_local_entry(unsigned int val) +{ + return (val >= 4 * 4 + ? (val >= 8 * 4 + ? (val >= 16 * 4 ? 6 : 5) + : 4) + : (val >= 2 * 4 + ? 3 + : (val >= 1 * 4 ? 2 : 0))); +} + +/* st_other to number of bytes. */ +#define PPC64_LOCAL_ENTRY_OFFSET(other) \ + ppc64_decode_local_entry (((other) & STO_PPC64_LOCAL_MASK) \ + >> STO_PPC64_LOCAL_BIT) +/* number of bytes to st_other. */ +#define PPC64_SET_LOCAL_ENTRY_OFFSET(val) \ + ppc64_encode_local_entry (val) << STO_PPC64_LOCAL_BIT + /* Specify the start of the .glink section. */ #define DT_PPC64_GLINK DT_LOPROC |