gint/fxcg50.ld
Lephe 4a3c396284
fxcg50: remove rram region and fxcg20-friendly VBR address
This change removes the RRAM region which was inherited from the fx9860g
memory layout but no longer relevant on fxcg50. This removed one
occurrence of a hardcoded user stack address in the linker script, the
other being the VBR address. But since the VBR only contains
position-independent code that is manually "relocated" at startup, the
linker script needs not actually use its value, so this is not a true
dependency.

gint should now more or less be able to boot up on an fxcg20, except for
the hardcoded VRAM addresses which need to be moved to the fxcg20 system
stack.
2020-06-18 09:59:31 +02:00

246 lines
5.8 KiB
Text

/*
Linker script for fxcg50 add-ins. Most symbols are used in the startup
routine in core/start.c; some others in core/setup.c.
*/
/* All fxcg50 have SH4 processors (finally rid of compatibility issues) */
OUTPUT_ARCH(sh4)
/* ELF offers a lot of symbol/section/relocation insights */
OUTPUT_FORMAT(elf32-sh)
/* Located in core/start.c */
ENTRY(_start)
MEMORY
{
/* Userspace mapping of the add-in (without G3A header) */
rom (rx): o = 0x00300000, l = 2M
/* Static RAM; stack grows down from the end of this region.
The first 0x2000 bytes are reserved by gint, see below */
ram (rw): o = 0x08101400, l = 507k
/* gint's VBR space at the start of the user stack on fx-CG 50 and on
fx-CG 20. This address needs not be determined now because VBR code
is position-independent and stored in ROM so the linker doesn't even
need to know the value */
vbr50 (rwx): o = 0x8c160000, l = 5k
vbr20 (rwx): o = 0x88160000, l = 5k
/* On-chip IL memory */
ilram (rwx): o = 0xe5200000, l = 4k
/* On-chip X and Y memory */
xram (rwx): o = 0xe5007000, l = 8k
yram (rwx): o = 0xe5017000, l = 8k
}
SECTIONS
{
/*
** ROM sections
*/
/* First address to be mapped to ROM */
_brom = 0x00300000;
/* Size of ROM mappings */
_srom = SIZEOF(.text) + SIZEOF(.rodata)
+ SIZEOF(.gint.drivers) + SIZEOF(.gint.blocks);
/* Machine code going to ROM:
- Initialization sections (.pretext.entry and .pretext)
- Compiler-provided constructors (.ctors) and destructors (.dtors)
- All text from .text and .text.* (including user code) */
.text : {
*(.pretext.entry)
*(.pretext)
_btors = . ;
*(.ctors .ctors.*)
_mtors = . ;
*(.dtors .dtors.*)
_etors = . ;
_gint_exch_start = . ;
*(.gint.exch)
_gint_exch_size = ABSOLUTE(. - _gint_exch_start);
_gint_tlbh_start = . ;
*(.gint.tlbh)
_gint_tlbh_size = ABSOLUTE(. - _gint_tlbh_start);
*(.text .text.*)
} > rom
/* Interrupt handlers going to ROM:
- gint's interrupt handler blocks (.gint.blocks)
Although gint's blocks end up in VBR space, they are installed at
startup by the library/drivers, so we store them here for now */
.gint.blocks : {
KEEP(*(.gint.blocks));
} > rom
/* Driver data going to ROM:
- Exposed driver interfaces (.gint.drivers)
The driver information is required to start and configure the
driver, even if the symbols are not referenced */
.gint.drivers : {
_bdrv = . ;
KEEP(*(.gint.drivers.0));
KEEP(*(.gint.drivers.1));
KEEP(*(.gint.drivers.2));
KEEP(*(.gint.drivers.3));
KEEP(*(.gint.drivers.4));
KEEP(*(.gint.drivers.5));
KEEP(*(.gint.drivers.6));
_edrv = . ;
} > rom
/* Read-only data going to ROM:
- Resources or assets from fxconv or similar converters
- Data marked read-only by the compiler (.rodata and .rodata.*) */
.rodata : SUBALIGN(4) {
/* Put these first, they need to be 4-aligned */
*(.rodata.4)
*(.rodata .rodata.*)
} > rom
/*
** RAM sections
*/
. = ORIGIN(ram);
/* BSS data going to RAM. The BSS section is to be stripped from the
ELF file later, and wiped at startup */
.bss (NOLOAD) : {
_rbss = . ;
*(.bss COMMON)
. = ALIGN(16);
} > ram :NONE
_sbss = SIZEOF(.bss);
/* Read-write data sections going to RAM (.data and .data.*) */
.data ALIGN(4) : ALIGN(4) {
_ldata = LOADADDR(.data);
_rdata = . ;
*(.data .data.*)
. = ALIGN(16);
} > ram AT> rom
/* Read-write data sub-aligned to 4 bytes (mainly from fxconv) */
.data.4 : SUBALIGN(4) {
*(.data.4)
. = ALIGN(16);
} > ram AT> rom
_sdata = SIZEOF(.data) + SIZEOF(.data.4);
/* On-chip memory sections: IL, X and Y memory */
. = ORIGIN(ilram);
.ilram ALIGN(4) : ALIGN(4) {
_lilram = LOADADDR(.ilram);
_rilram = . ;
*(.ilram)
/* Code that must remain mapped is placed here */
*(.gint.mapped)
. = ALIGN(16);
} > ilram AT> rom
. = ORIGIN(xram);
.xram ALIGN(4) : ALIGN(4) {
_lxram = LOADADDR(.xram);
_rxram = . ;
*(.xram)
. = ALIGN(16);
} > xram AT> rom
. = ORIGIN(yram);
.yram ALIGN(4) : ALIGN(4) {
_lyram = LOADADDR(.yram);
_ryram = . ;
*(.yram)
. = ALIGN(16);
} > yram AT> rom
_silram = SIZEOF(.ilram);
_sxram = SIZEOF(.xram);
_syram = SIZEOF(.yram);
/*
** gint-related sections
** 8c160000:5k VBR space
** 8c161400:3k .gint.data and .gint.bss
*/
/* VBR address: let's just start at the beginning of the RAM area.
There's an unused 0x100-byte gap at the start of the VBR space.
The VBR space is already a large block (> 2 kiB), so I'm cutting off
the gap to spare some memory */
_gint_vbr_fxcg50 = ORIGIN(vbr50) - 0x100;
_gint_vbr_fxcg20 = ORIGIN(vbr20) - 0x100;
. = ORIGIN(ram) + _sbss + _sdata;
/* gint's data section, going to static RAM. This section contains many
small objects from the library (static/global variables, etc) */
.gint.data ALIGN(4) : ALIGN(4) {
_lgdata = LOADADDR(.gint.data);
_rgdata = . ;
*(.gint.data .gint.data.*)
. = ALIGN(16);
} > ram AT> rom
_sgdata = SIZEOF(.gint.data);
/* gint's uninitialized BSS section, going to static RAM. All the large
data arrays will be located here */
.gint.bss (NOLOAD) : {
/* Since it's uninitialized, the location doesn't matter */
*(.gint.bss .gint.bss.*)
. = ALIGN(16);
} > ram :NONE
_sgbss = SIZEOF(.gint.bss);
/*
** Other sections
*/
/* Unwanted sections going to meet Dave Null:
- SH3-only data sections
- Debug sections, often come out of libgcc
- Java classes registration (why is there any of this here?)
- Asynchronous unwind tables: no C++ exception handling for now ^^
- Comments or anything the compiler might put in its assembler */
/DISCARD/ : {
*(.gint.bss.sh3)
*(.gint.data.sh3)
*(.debug_info .debug_abbrev .debug_loc .debug_aranges
.debug_ranges .debug_line .debug_str)
*(.jcr)
*(.eh_frame_hdr)
*(.eh_frame)
*(.comment)
}
}