| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137 |
- From 1dea576eac4289602adc4a37f48c80330bf82e63 Mon Sep 17 00:00:00 2001
- From: Damien Le Moal <damien.lemoal@wdc.com>
- Date: Wed, 9 Sep 2020 17:31:33 +0900
- Subject: [PATCH] elf2flt: add riscv 64-bits support
- Add support for riscv 64bits ISA by defining the relocation types
- R_RISCV_32_PCREL, R_RISCV_ADD32, R_RISCV_SUB32, R_RISCV_32 and
- R_RISCV_64. riscv64 support also needs the __global_pointer$ symbol to
- be defined right after the relocation tables in the data section.
- Furthermore, the .got and .got.plt sections must be reversed. These 2
- requirements are handled with runtime modifications of the default
- linker script using the append_sed() function.
- (1) For the .got.plt and .got sections order swap, append_sed() is used
- to rename "(.got.plt)" to "(.got.tmp)" and to rename "(.got)" to
- "(.got.plt)". A last call finalize the name swap by replacing
- "(.got.tmp)" with "(.got)"
- (2) For the global pointer synbol, a definition line starting with
- "RISCV_GP" is added. The "RISCV_GP" string is removed if the target CPU
- type is riscv64. The definition line is dropped for other CPU types.
- With these changes, buildroot/busybox builds and run on NOMMU
- systems with kernel 5.13. Tested on Canaan Kendryte K210 boards.
- This patch is based on earlier work by Christoph Hellwig <hch@lst.de>.
- Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
- ---
- elf2flt.c | 23 +++++++++++++++++++++++
- elf2flt.ld.in | 9 +++++----
- ld-elf2flt.c | 16 ++++++++++++++++
- 3 files changed, 44 insertions(+), 4 deletions(-)
- diff --git a/elf2flt.c b/elf2flt.c
- index f87f1fc..dbce467 100644
- --- a/elf2flt.c
- +++ b/elf2flt.c
- @@ -80,6 +80,8 @@ const char *elf2flt_progname;
- #include <elf/v850.h>
- #elif defined(TARGET_xtensa)
- #include <elf/xtensa.h>
- +#elif defined(TARGET_riscv64)
- +#include <elf/riscv.h>
- #endif
-
- #if defined(__MINGW32__)
- @@ -122,6 +124,8 @@ const char *elf2flt_progname;
- #define ARCH "nios2"
- #elif defined(TARGET_xtensa)
- #define ARCH "xtensa"
- +#elif defined(TARGET_riscv64)
- +#define ARCH "riscv64"
- #else
- #error "Don't know how to support your CPU architecture??"
- #endif
- @@ -797,6 +801,16 @@ output_relocs (
- goto good_32bit_resolved_reloc;
- default:
- goto bad_resolved_reloc;
- +#elif defined(TARGET_riscv64)
- + case R_RISCV_32_PCREL:
- + case R_RISCV_ADD32:
- + case R_RISCV_SUB32:
- + continue;
- + case R_RISCV_32:
- + case R_RISCV_64:
- + goto good_32bit_resolved_reloc;
- + default:
- + goto bad_resolved_reloc;
- #else
- default:
- /* The default is to assume that the
- @@ -1806,6 +1820,15 @@ int main(int argc, char *argv[])
- if (!load_to_ram && !pfile)
- load_to_ram = 1;
-
- +#if defined(TARGET_riscv64)
- + /*
- + * riscv only supports loading text and data contiguously.
- + * So fail if load_to_ram is false.
- + */
- + if (!load_to_ram)
- + fatal("Loading to RAM ('-r' option) is required");
- +#endif
- +
- fname = argv[argc-1];
-
- if (pfile) {
- diff --git a/elf2flt.ld.in b/elf2flt.ld.in
- index ec1fe6f..c0c44b8 100644
- --- a/elf2flt.ld.in
- +++ b/elf2flt.ld.in
- @@ -70,10 +70,11 @@ W_RODAT *(.gnu.linkonce.r*)
- . = ALIGN(0x20) ;
- LONG(-1)
- . = ALIGN(0x20) ;
- -R_RODAT *(.rodata)
- -R_RODAT *(.rodata1)
- -R_RODAT *(.rodata.*)
- -R_RODAT *(.gnu.linkonce.r*)
- +RISCV_GP: __global_pointer$ = . + 0x800 ;
- +R_RODAT *(.rodata)
- +R_RODAT *(.rodata1)
- +R_RODAT *(.rodata.*)
- +R_RODAT *(.gnu.linkonce.r*)
- *(.data)
- *(.data1)
- *(.data.*)
- diff --git a/ld-elf2flt.c b/ld-elf2flt.c
- index e5de506..31b565f 100644
- --- a/ld-elf2flt.c
- +++ b/ld-elf2flt.c
- @@ -324,6 +324,22 @@ static int do_final_link(void)
- append_option(&other_options, concat(got_offset, "=", buf, NULL));
- }
-
- + if (streq(TARGET_CPU, "riscv64")) {
- + /*
- + * The .got section must come before the .got.plt section
- + * (gcc/ld bug ?).
- + */
- + append_sed(&sed, "(.got.plt)", "(.got.tmp)");
- + append_sed(&sed, "(.got.plt)", "(.got)");
- + append_sed(&sed, "(.got.tmp)", "(.got.plt)");
- +
- + /* The global pointer symbol is defined after the GOT. */
- + append_sed(&sed, "^RISCV_GP:", "");
- + } else {
- + /* Get rid of the global pointer definition. */
- + append_sed(&sed, "^RISCV_GP:", NULL);
- + }
- +
- /* Locate the default linker script, if we don't have one provided. */
- if (!linker_script)
- linker_script = concat(ldscriptpath, "/elf2flt.ld", NULL);
- --
- 2.31.1
|
