[Buildroot] [PATCH v2 3/6] package/elf2flt: add RISC-V support

Damien Le Moal damien.lemoal at wdc.com
Tue Sep 8 11:33:21 UTC 2020


From: Christoph Hellwig <hch at lst.de>

Enable selecting elf2flt for RISC-V no MMU builds ad add support for it.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal at wdc.com>
---
 .../0002-elf2flt-add-riscv-support.patch      | 302 ++++++++++++++++++
 package/elf2flt/Config.in.host                |   2 +-
 2 files changed, 303 insertions(+), 1 deletion(-)
 create mode 100644 package/elf2flt/0002-elf2flt-add-riscv-support.patch

diff --git a/package/elf2flt/0002-elf2flt-add-riscv-support.patch b/package/elf2flt/0002-elf2flt-add-riscv-support.patch
new file mode 100644
index 0000000000..2f3ce5ac69
--- /dev/null
+++ b/package/elf2flt/0002-elf2flt-add-riscv-support.patch
@@ -0,0 +1,302 @@
+From 9a1c84590f31897e681a8142481c73456a7eedcf Mon Sep 17 00:00:00 2001
+From: Christoph Hellwig <hch at lst.de>
+Date: Mon, 10 Jun 2019 09:21:57 +0200
+Subject: elf2flt: add riscv support
+
+We need a new linker script - riscv has a global_pointer and is
+very picky about some section ordering.
+
+Signed-off-by: Christoph Hellwig <hch at lst.de>
+---
+ Makefile.in        |   4 +-
+ elf2flt.c          |  15 ++-
+ riscv64-elf2flt.ld | 222 +++++++++++++++++++++++++++++++++++++++++++++
+ 3 files changed, 239 insertions(+), 2 deletions(-)
+ create mode 100644 riscv64-elf2flt.ld
+
+diff --git a/Makefile.in b/Makefile.in
+index 52b3347..3b0b604 100644
+--- a/Makefile.in
++++ b/Makefile.in
+@@ -43,7 +43,9 @@ endif
+ LDFILE= elf2flt.ld
+ ifeq ($(strip $(CPU)),e1)
+ SRC_LDFILE= $(srcdir)/$(CPU)-elf2flt.ld
+-else 
++else ifeq ($(strip $(CPU)),riscv64)
++SRC_LDFILE= riscv64-elf2flt.ld
++else
+ SRC_LDFILE= elf2flt.ld
+ endif
+ 
+diff --git a/elf2flt.c b/elf2flt.c
+index 67f720a..81c9456 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
+@@ -507,7 +511,16 @@ output_relocs (
+ 				   them.  */ 
+ 				continue;
+ 			}
+-#endif /* USE_V850_RELOCS */
++#endif /* TARGET_v850 */
++
++#if defined(TARGET_riscv64)
++			switch ((*p)->howto->type) {
++			case R_RISCV_ADD32:
++			case R_RISCV_SUB32:
++			case R_RISCV_32_PCREL:
++			    continue;
++			}
++#endif
+ 
+ 			q = *p;
+ 			if (q->sym_ptr_ptr && *q->sym_ptr_ptr) {
+diff --git a/riscv64-elf2flt.ld b/riscv64-elf2flt.ld
+new file mode 100644
+index 0000000..89ac2e8
+--- /dev/null
++++ b/riscv64-elf2flt.ld
+@@ -0,0 +1,222 @@
++
++ENTRY (_start)
++
++SECTIONS {
++
++	.text 0x0 : {
++		. = . + 4;
++		. = ALIGN(0x4) ;
++		_stext = . ;
++		*(.literal .text)
++		*(.literal.* .text.*)
++		*(.gnu.warning)
++		*(.stub)
++		*(.gnu.linkonce.literal.*)
++		*(.gnu.linkonce.t*)
++		*(.glue_7t)
++		*(.glue_7)
++		*(.jcr)
++		*(.init.literal)
++		KEEP (*(.init))
++		*(.fini.literal)
++		KEEP (*(.fini))
++
++W_RODAT		*(.rodata)
++W_RODAT		*(.rodata1)
++W_RODAT		*(.rodata.*)
++W_RODAT		*(.gnu.linkonce.r*)
++
++		/* .ARM.extab name sections containing exception unwinding information */
++		*(.ARM.extab* .gnu.linkonce.armextab.*)
++		/* This is special code area at the end of the normal
++		   text section.  It contains a small lookup table at
++		   the start followed by the code pointed to by entries
++		   in the lookup table.  */
++		. = ALIGN (4) ;
++		PROVIDE(__ctbp = .);
++		*(.call_table_data)
++		*(.call_table_text)
++	}
++
++	/* .ARM.exidx name sections containing index entries for section unwinding */
++	/* .ARM.exidx is sorted, so has to go in its own output section.  */
++	__exidx_start = .;
++	.ARM.exidx :
++	{
++		*(.ARM.exidx* .gnu.linkonce.armexidx.*)
++	}
++	__exidx_end = .;
++
++	. = ALIGN(0x20) ;
++	_etext = . ;
++
++	.data : {
++		. = ALIGN(0x4) ;
++		_sdata = . ;
++		__data_start = . ;
++		data_start = . ;
++		*(.got)
++		*(.igot)
++  		*(.got.plt)
++		*(.igot.plt)
++		FILL(0) ;
++		. = ALIGN(0x20) ;
++		LONG(-1)
++		. = ALIGN(0x20) ;
++
++		__global_pointer$ = . + 0x800;
++
++		*(.data)
++		*(.data1)
++		*(.data.*)
++		*(.gnu.linkonce.d*)
++R_RODAT		*(.rodata)
++R_RODAT		*(.rodata1)
++R_RODAT		*(.rodata.*)
++R_RODAT		*(.gnu.linkonce.r*)
++
++		/* Microblaze has .sdata and .sbss (small bss).  They must
++		   be contiguous, so please don't move any of this. JW */
++		_ssrw = . ;
++		*(.srodata)
++		*(.srodata.*)
++		*(.sdata)
++		*(.sdata.*)
++		*(.sbss)			/* Don't move this! */
++		*(.gnu.linkonce.sb*)
++		_essrw = . ;
++
++		_ssrw_size = _essrw - _ssrw;
++		PROVIDE(_SDA_BASE_ = _ssrw + (_ssrw_size / 2));
++
++		*(.gnu.linkonce.s.*)
++		*(__libc_atexit)
++		*(__libc_subinit)
++		*(__libc_subfreeres)
++
++		/* microblaze-specific read-only small data area
++		   and associated locating symbols */
++		_ssro = . ;
++		*(.sdata2)
++		_essro = . ;
++		_ssro_size = _essro - _ssro;
++		PROVIDE(_SDA2_BASE_ = _ssro + (_ssro_size / 2));
++
++		. = ALIGN(4) ;
++TOR:		__CTOR_LIST__ = .;
++TOR:		LONG((__CTOR_END__ - __CTOR_LIST__) / 4 - 2)
++SINGLE_LINK:	/* gcc uses crtbegin.o to find the start of
++SINGLE_LINK:	   the constructors, so we make sure it is
++SINGLE_LINK:	   first.  Because this is a wildcard, it
++SINGLE_LINK:	   doesn't matter if the user does not
++SINGLE_LINK:	   actually link against crtbegin.o; the
++SINGLE_LINK:	   linker won't look for a file to match a
++SINGLE_LINK:	   wildcard.  The wildcard also means that it
++SINGLE_LINK:	   doesn't matter which directory crtbegin.o
++SINGLE_LINK:	   is in.  */
++SINGLE_LINK:	KEEP (*crtbegin*.o(.ctors))
++SINGLE_LINK:	/* We don't want to include the .ctor section from
++SINGLE_LINK:	   from the crtend.o file until after the sorted ctors.
++SINGLE_LINK:	   The .ctor section from the crtend file contains the
++SINGLE_LINK:	   end of ctors marker and it must be last */
++SINGLE_LINK:	KEEP (*(EXCLUDE_FILE (*crtend*.o ) .ctors))
++SINGLE_LINK:	KEEP (*(SORT(.ctors.*)))
++		KEEP (*(.ctors))
++TOR:		LONG(0)
++TOR:		__CTOR_END__ = .;
++TOR:		__DTOR_LIST__ = .;
++TOR:		LONG((__DTOR_END__ - __DTOR_LIST__) / 4 - 2)
++SINGLE_LINK:	KEEP (*crtbegin*.o(.dtors))
++SINGLE_LINK:	KEEP (*(EXCLUDE_FILE (*crtend*.o ) .dtors))
++SINGLE_LINK:	KEEP (*(SORT(.dtors.*)))
++		KEEP (*(.dtors))
++TOR:		LONG(0)
++TOR:		__DTOR_END__ = .;
++
++		PROVIDE (__preinit_array_start = .);
++		KEEP (*(.preinit_array))
++		PROVIDE (__preinit_array_end = .);
++
++		PROVIDE (__init_array_start = .);
++		KEEP (*(SORT(.init_array.*)))
++		KEEP (*(.init_array))
++		PROVIDE (__init_array_end = .);
++
++		PROVIDE (__fini_array_start = .);
++		KEEP (*(.fini_array))
++		KEEP (*(SORT(.fini_array.*)))
++		PROVIDE (__fini_array_end = .);
++	}
++
++	.note.ABI-tag : { *(.note.ABI-tag) }
++	.eh_frame_hdr : { *(.eh_frame_hdr) }
++	.eh_frame : { KEEP(*(.eh_frame)) }
++	.gcc_except_table : {
++		KEEP(*(.gcc_except_table))
++		KEEP(*(.gcc_except_table.*))
++	}
++
++	. = ALIGN(0x10) ;
++	_edata = . ;
++
++	.bss : {
++		. = ALIGN(0x4) ;
++		_sbss = ALIGN(0x4) ;
++		__bss_start = . ;
++		*(.dynsbss)
++		*(.sbss)
++		*(.sbss.*)
++		*(.scommon)
++		*(.dynbss)
++		*(.bss)
++		*(.bss.*)
++		*(.bss*)
++		*(.gnu.linkonce.b*)
++		*(COMMON)
++		. = ALIGN(0x10) ;
++		_ebss = . ;
++		_end = . ;
++		end = . ;
++	}
++
++	.stack : {
++		. = ALIGN(0x4);
++		_stack_start = .;
++	}
++
++	.junk 0 : { *(.rel*) *(.rela*) }
++	/DISCARD/ : { *(.note.GNU-stack) }
++	/* Stabs debugging sections.    */
++	.stab 0 : { *(.stab) }
++	.stabstr 0 : { *(.stabstr) }
++	.stab.excl 0 : { *(.stab.excl) }
++	.stab.exclstr 0 : { *(.stab.exclstr) }
++	.stab.index 0 : { *(.stab.index) }
++	.stab.indexstr 0 : { *(.stab.indexstr) }
++	.comment 0 : { *(.comment) }
++	/* DWARF debug sections.
++	   Symbols in the DWARF debugging sections are relative to the beginning
++	   of the section so we begin them at 0.  */
++	/* DWARF 1 */
++	.debug          0 : { *(.debug) }
++	.line           0 : { *(.line) }
++	/* GNU DWARF 1 extensions */
++	.debug_srcinfo  0 : { *(.debug_srcinfo) }
++	.debug_sfnames  0 : { *(.debug_sfnames) }
++	/* DWARF 1.1 and DWARF 2 */
++	.debug_aranges  0 : { *(.debug_aranges) }
++	.debug_pubnames 0 : { *(.debug_pubnames) }
++	/* DWARF 2 */
++	.debug_info     0 : { *(.debug_info .gnu.linkonce.wi.*) }
++	.debug_abbrev   0 : { *(.debug_abbrev) }
++	.debug_line     0 : { *(.debug_line) }
++	.debug_frame    0 : { *(.debug_frame) }
++	.debug_str      0 : { *(.debug_str) }
++	.debug_loc      0 : { *(.debug_loc) }
++	.debug_macinfo  0 : { *(.debug_macinfo) }
++	/* SGI/MIPS DWARF 2 extensions */
++	.debug_weaknames 0 : { *(.debug_weaknames) }
++	.debug_funcnames 0 : { *(.debug_funcnames) }
++	.debug_typenames 0 : { *(.debug_typenames) }
++	.debug_varnames  0 : { *(.debug_varnames) }
++}
+-- 
+2.20.1
+
diff --git a/package/elf2flt/Config.in.host b/package/elf2flt/Config.in.host
index d6685a7ff6..2010526e04 100644
--- a/package/elf2flt/Config.in.host
+++ b/package/elf2flt/Config.in.host
@@ -1,6 +1,6 @@
 config BR2_PACKAGE_HOST_ELF2FLT
 	bool "Enable elf2flt support?"
-	depends on BR2_arm || BR2_sh || BR2_sparc || BR2_xtensa
+	depends on BR2_arm || BR2_sh || BR2_sparc || BR2_xtensa || BR2_riscv
 	depends on !BR2_USE_MMU
 	help
 	  uCLinux uses a Binary Flat format commonly known as BFLT. It
-- 
2.26.2




More information about the buildroot mailing list