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Diffstat (limited to 'include/bout.h')
| -rw-r--r-- | include/bout.h | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/include/bout.h b/include/bout.h new file mode 100644 index 00000000000..8fc28cc3d6d --- /dev/null +++ b/include/bout.h @@ -0,0 +1,182 @@ +/* + * This file is a modified version of 'a.out.h'. It is to be used in all + * GNU tools modified to support the i80960 (or tools that operate on + * object files created by such tools). + * + * All i80960 development is done in a CROSS-DEVELOPMENT environment. I.e., + * object code is generated on, and executed under the direction of a symbolic + * debugger running on, a host system. We do not want to be subject to the + * vagaries of which host it is or whether it supports COFF or a.out format, + * or anything else. We DO want to: + * + * o always generate the same format object files, regardless of host. + * + * o have an 'a.out' header that we can modify for our own purposes + * (the 80960 is typically an embedded processor and may require + * enhanced linker support that the normal a.out.h header can't + * accommodate). + * + * As for byte-ordering, the following rules apply: + * + * o Text and data that is actually downloaded to the target is always + * in i80960 (little-endian) order. + * + * o All other numbers (in the header, symbols, relocation directives) + * are in host byte-order: object files CANNOT be lifted from a + * little-end host and used on a big-endian (or vice versa) without + * modification. + * ==> THIS IS NO LONGER TRUE USING BFD. WE CAN GENERATE ANY BYTE ORDER + * FOR THE HEADER, AND READ ANY BYTE ORDER. PREFERENCE WOULD BE TO + * USE LITTLE-ENDIAN BYTE ORDER THROUGHOUT, REGARDLESS OF HOST. <== + * + * o The downloader ('comm960') takes care to generate a pseudo-header + * with correct (i80960) byte-ordering before shipping text and data + * off to the NINDY monitor in the target systems. Symbols and + * relocation info are never sent to the target. + */ + + +#define BMAGIC 0415 +/* We don't accept the following (see N_BADMAG macro). + * They're just here so GNU code will compile. + */ +#define OMAGIC 0407 /* old impure format */ +#define NMAGIC 0410 /* read-only text */ +#define ZMAGIC 0413 /* demand load format */ + +/* FILE HEADER + * All 'lengths' are given as a number of bytes. + * All 'alignments' are for relinkable files only; an alignment of + * 'n' indicates the corresponding segment must begin at an + * address that is a multiple of (2**n). + */ +struct external_exec { + /* Standard stuff */ + unsigned char e_info[4]; /* Identifies this as a b.out file */ + unsigned char e_text[4]; /* Length of text */ + unsigned char e_data[4]; /* Length of data */ + unsigned char e_bss[4]; /* Length of uninitialized data area */ + unsigned char e_syms[4]; /* Length of symbol table */ + unsigned char e_entry[4]; /* Runtime start address */ + unsigned char e_trsize[4]; /* Length of text relocation info */ + unsigned char e_drsize[4]; /* Length of data relocation info */ + + /* Added for i960 */ + unsigned char e_tload[4]; /* Text runtime load address */ + unsigned char e_dload[4]; /* Data runtime load address */ + unsigned char e_talign[1]; /* Alignment of text segment */ + unsigned char e_dalign[1]; /* Alignment of data segment */ + unsigned char e_balign[1]; /* Alignment of bss segment */ + unsigned char e_relaxable[1]; /* Assembled with enough info to allow linker to relax */ +}; + +#define EXEC_BYTES_SIZE (sizeof (struct external_exec)) + +/* These macros use the a_xxx field names, since they operate on the exec + structure after it's been byte-swapped and realigned on the host machine. */ +#define N_BADMAG(x) (((x).a_info)!=BMAGIC) +#define N_TXTOFF(x) EXEC_BYTES_SIZE +#define N_DATOFF(x) ( N_TXTOFF(x) + (x).a_text ) +#define N_TROFF(x) ( N_DATOFF(x) + (x).a_data ) +#define N_TRELOFF N_TROFF +#define N_DROFF(x) ( N_TROFF(x) + (x).a_trsize ) +#define N_DRELOFF N_DROFF +#define N_SYMOFF(x) ( N_DROFF(x) + (x).a_drsize ) +#define N_STROFF(x) ( N_SYMOFF(x) + (x).a_syms ) +#define N_DATADDR(x) ( (x).a_dload ) + +/* Address of text segment in memory after it is loaded. */ +#if !defined (N_TXTADDR) +#define N_TXTADDR(x) 0 +#endif + +/* A single entry in the symbol table + */ +struct nlist { + union { + char *n_name; + struct nlist *n_next; + long n_strx; /* Index into string table */ + } n_un; + unsigned char n_type; /* See below */ + char n_other; /* Used in i80960 support -- see below */ + short n_desc; + unsigned long n_value; +}; + + +/* Legal values of n_type + */ +#define N_UNDF 0 /* Undefined symbol */ +#define N_ABS 2 /* Absolute symbol */ +#define N_TEXT 4 /* Text symbol */ +#define N_DATA 6 /* Data symbol */ +#define N_BSS 8 /* BSS symbol */ +#define N_FN 31 /* Filename symbol */ + +#define N_EXT 1 /* External symbol (OR'd in with one of above) */ +#define N_TYPE 036 /* Mask for all the type bits */ +#define N_STAB 0340 /* Mask for all bits used for SDB entries */ + +/* MEANING OF 'n_other' + * + * If non-zero, the 'n_other' fields indicates either a leaf procedure or + * a system procedure, as follows: + * + * 1 <= n_other <= 32 : + * The symbol is the entry point to a system procedure. + * 'n_value' is the address of the entry, as for any other + * procedure. The system procedure number (which can be used in + * a 'calls' instruction) is (n_other-1). These entries come from + * '.sysproc' directives. + * + * n_other == N_CALLNAME + * the symbol is the 'call' entry point to a leaf procedure. + * The *next* symbol in the symbol table must be the corresponding + * 'bal' entry point to the procedure (see following). These + * entries come from '.leafproc' directives in which two different + * symbols are specified (the first one is represented here). + * + * + * n_other == N_BALNAME + * the symbol is the 'bal' entry point to a leaf procedure. + * These entries result from '.leafproc' directives in which only + * one symbol is specified, or in which the same symbol is + * specified twice. + * + * Note that an N_CALLNAME entry *must* have a corresponding N_BALNAME entry, + * but not every N_BALNAME entry must have an N_CALLNAME entry. + */ +#define N_CALLNAME ((char)-1) +#define N_BALNAME ((char)-2) +#define IS_CALLNAME(x) (N_CALLNAME == (x)) +#define IS_BALNAME(x) (N_BALNAME == (x)) +#define IS_OTHER(x) ((x)>0 && (x) <=32) + +#define b_out_relocation_info relocation_info +struct relocation_info { + int r_address; /* File address of item to be relocated */ + unsigned +#define r_index r_symbolnum + r_symbolnum:24,/* Index of symbol on which relocation is based, + * if r_extern is set. Otherwise set to + * either N_TEXT, N_DATA, or N_BSS to + * indicate section on which relocation is + * based. + */ + r_pcrel:1, /* 1 => relocate PC-relative; else absolute + * On i960, pc-relative implies 24-bit + * address, absolute implies 32-bit. + */ + r_length:2, /* Number of bytes to relocate: + * 0 => 1 byte + * 1 => 2 bytes -- used for 13 bit pcrel + * 2 => 4 bytes + */ + r_extern:1, + r_bsr:1, /* Something for the GNU NS32K assembler */ + r_disp:1, /* Something for the GNU NS32K assembler */ + r_callj:1, /* 1 if relocation target is an i960 'callj' */ + r_relaxable:1; /* 1 if enough info is left to relax + the data */ +}; |