| 1 |
2 |
ja_rd |
/**
|
| 2 |
|
|
* ion_noxram.lds -- Linker script file for ION project (with no RAM or cache)
|
| 3 |
|
|
*
|
| 4 |
|
|
* The ion cpu has separate buses for code and data (Harvard architecture) but
|
| 5 |
|
|
* does not have caches by default. This linker script targets that 'bare'
|
| 6 |
|
|
* system configuration. It is meant for early testing and debugging.
|
| 7 |
|
|
*
|
| 8 |
|
|
* This script will split the object file in two areas so that they can be put
|
| 9 |
|
|
* in separate memory blocks:
|
| 10 |
|
|
* 1.- Code area (text output section)
|
| 11 |
|
|
* 2.- Data area (sdata, data and bss output sections)
|
| 12 |
|
|
*
|
| 13 |
|
|
* Since data constants can't be reached from the code bus, constant data
|
| 14 |
|
|
* (usually in section rodata) needs to be put in the same space as other data.
|
| 15 |
|
|
* This is the main purpose of this file.
|
| 16 |
|
|
* Alternatively, we might jus implement a 3-port memory and leave all sections
|
| 17 |
|
|
* adjacent, but that would be too expensive (3-port memory would take about
|
| 18 |
|
|
* twice as many memory blocks for the same memory size).
|
| 19 |
|
|
*
|
| 20 |
|
|
* FIXME code and data RAM block sizes hardcoded
|
| 21 |
|
|
* FIXME code and data start addresses hardcoded
|
| 22 |
|
|
*/
|
| 23 |
|
|
|
| 24 |
|
|
/* Make sure the first linked file is ths startup code from boot.s */
|
| 25 |
|
|
/* (We might put boot.o in the ld command line, BEFORE all other files) */
|
| 26 |
|
|
STARTUP(boot.o)
|
| 27 |
|
|
|
| 28 |
|
|
/* Default object output format is ELF big endian */
|
| 29 |
|
|
OUTPUT_FORMAT(elf32-big)
|
| 30 |
|
|
|
| 31 |
|
|
|
| 32 |
|
|
|
| 33 |
|
|
SECTIONS {
|
| 34 |
|
|
/* Put all code at CODE area */
|
| 35 |
|
|
.text 0x00000000 : {
|
| 36 |
|
|
_ftext = . ;
|
| 37 |
|
|
* (.text);
|
| 38 |
|
|
|
| 39 |
|
|
|
| 40 |
|
|
} = 0 /* fill gaps with zeros */
|
| 41 |
|
|
|
| 42 |
|
|
/* Mark end of executable code */
|
| 43 |
|
|
_ecode = .;
|
| 44 |
|
|
/* mark end of read-only code */
|
| 45 |
|
|
_etext = .;
|
| 46 |
|
|
PROVIDE (etext = .);
|
| 47 |
|
|
|
| 48 |
|
|
|
| 49 |
|
|
/**** Put all data, including read-only, at DATA area */
|
| 50 |
|
|
|
| 51 |
|
|
.data 0x00010000 : {
|
| 52 |
|
|
_fdata = . ;
|
| 53 |
|
|
* (.data);
|
| 54 |
|
|
* (.data.*);
|
| 55 |
|
|
|
| 56 |
|
|
/* Conventionally, symbol _gp points to the middle of a 64K area at the
|
| 57 |
|
|
start of the sdata section ('small data section'). Register $gp is
|
| 58 |
|
|
loaded with _gp at program startup (in boot.s) so that data in that
|
| 59 |
|
|
area can be reached with just one instruction.
|
| 60 |
|
|
Note that the compiler/assembler will put data in the sdata section
|
| 61 |
|
|
only if it is small enough (see as/gcc docs, -G option and others).
|
| 62 |
|
|
FIXME this feature has not been tested.
|
| 63 |
|
|
*/
|
| 64 |
|
|
_gp = . + 0x7ff0; /* 0x7ff0 -> middle of 64K area */
|
| 65 |
|
|
*(.lit8);
|
| 66 |
|
|
*(.lit4);
|
| 67 |
|
|
*(.sdata);
|
| 68 |
|
|
*(.sbss);
|
| 69 |
|
|
*(.gnu.linkonce.s*);
|
| 70 |
|
|
*(.rodata);
|
| 71 |
|
|
*(.rodata.*);
|
| 72 |
|
|
/* mark end of initialised data */
|
| 73 |
|
|
_edata = .;
|
| 74 |
|
|
PROVIDE (edata = .);
|
| 75 |
|
|
|
| 76 |
|
|
/* start bss on dword boundary for easier clearing */
|
| 77 |
|
|
. = ALIGN(8);
|
| 78 |
|
|
|
| 79 |
|
|
}
|
| 80 |
|
|
|
| 81 |
|
|
/* start bss on dword boundary for easier clearing */
|
| 82 |
|
|
. = ALIGN(8);
|
| 83 |
|
|
|
| 84 |
|
|
/* mark start of uninitialised data */
|
| 85 |
|
|
__bss_start = .;
|
| 86 |
|
|
_fbss = __bss_start;
|
| 87 |
|
|
|
| 88 |
|
|
.bss : {
|
| 89 |
|
|
/* *(.sbss); */
|
| 90 |
|
|
*(.dynbss);
|
| 91 |
|
|
*(COMMON);
|
| 92 |
|
|
* (.bss);
|
| 93 |
|
|
_end = . ;
|
| 94 |
|
|
}
|
| 95 |
|
|
/* mark end of uninitialised data */
|
| 96 |
|
|
_end = . ;
|
| 97 |
|
|
PROVIDE (end = .);
|
| 98 |
|
|
}
|
