freebsd-skq/sys/riscv/include/md_var.h
Mitchell Horne ffedb98b3e RISC-V: expose extension bits in AT_HWCAP
AT_HWCAP is a field in the elf auxiliary vector meant to describe
cpu-specific hardware features. For RISC-V we want to use this to
indicate the presence of any standard extensions supported by the CPU.
This allows userland applications to query the system for supported
extensions using elf_aux_info(3).

Support for an extension is indicated by the presence of its
corresponding bit in AT_HWCAP -- e.g. systems supporting the 'c'
extension (compressed instructions) will have the second bit set.

Extensions advertised through AT_HWCAP are only those that are supported
by all harts in the system.

Reviewed by:	jhb, markj
Approved by:	markj (mentor)
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D20493
2019-06-11 00:55:54 +00:00

51 lines
2.0 KiB
C

/*-
* Copyright (c) 1995 Bruce D. Evans.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the names of contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: FreeBSD: src/sys/i386/include/md_var.h,v 1.40 2001/07/12
* $FreeBSD$
*/
#ifndef _MACHINE_MD_VAR_H_
#define _MACHINE_MD_VAR_H_
extern long Maxmem;
extern char sigcode[];
extern int szsigcode;
extern uint64_t *vm_page_dump;
extern int vm_page_dump_size;
extern u_long elf_hwcap;
struct dumperinfo;
void busdma_swi(void);
void dump_add_page(vm_paddr_t);
void dump_drop_page(vm_paddr_t);
int minidumpsys(struct dumperinfo *);
#endif /* !_MACHINE_MD_VAR_H_ */