From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <48737414.3000903@wmipf.in-berlin.de>
Date: Tue,  8 Jul 2008 16:05:08 +0200
From: =?UTF-8?B?TWljaGFlbCBUZWljaGdyw6RiZXI=?= <mt@wmipf.in-berlin.de>
User-Agent: Icedove 1.5.0.14eol (X11/20080509)
MIME-Version: 1.0
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
References: <6a3ae47e0807080601m30b6da97w782bde83f91055cf@mail.gmail.com>
In-Reply-To: <6a3ae47e0807080601m30b6da97w782bde83f91055cf@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Subject: Re: [9fans] P9P libthread on Debian ARM vs. makecontext et al.
Topicbox-Message-UUID: de2a85ae-ead3-11e9-9d60-3106f5b1d025

> The code in Linux.c that implements makecontext() for ARM expects this
> struct to contain a gregs array. I'm guessing that gregs is the same
> as the enumerated arm_* ones above. So, would I be correct in assuming
> that gregs[13] is arm_sp and gregs[14] is arm_lr?

Hi, I would say yes, as SP is r13 and LR is r14 on arm.
To run Russ' libtask on arm7 I used the Linux-arm-asm.s and
the arm-specific makecontext implementation from Linux.c,
as well as the following structures.

M.
--

enum {
	NREG = 16,
};

typedef
struct Mcontext
{
	u32int	gregs[NREG];	/* general registers */
} Mcontext;

typedef
struct ucontext
{
	Mcontext	uc_mcontext;
	sigset_t uc_sigmask;
	struct {
		void		*ss_sp;
		u16int	ss_size;
	} uc_stack;

} ucontext_t;