minix/kernel/system/do_segctl.c
Ben Gras 6f77685609 Split of architecture-dependent and -independent functions for i386,
mainly in the kernel and headers. This split based on work by
Ingmar Alting <iaalting@cs.vu.nl> done for his Minix PowerPC architecture
port.

 . kernel does not program the interrupt controller directly, do any
   other architecture-dependent operations, or contain assembly any more,
   but uses architecture-dependent functions in arch/$(ARCH)/.
 . architecture-dependent constants and types defined in arch/$(ARCH)/include.
 . <ibm/portio.h> moved to <minix/portio.h>, as they have become, for now,
   architecture-independent functions.
 . int86, sdevio, readbios, and iopenable are now i386-specific kernel calls
   and live in arch/i386/do_* now.
 . i386 arch now supports even less 86 code; e.g. mpx86.s and klib86.s have
   gone, and 'machine.protected' is gone (and always taken to be 1 in i386).
   If 86 support is to return, it should be a new architecture.
 . prototypes for the architecture-dependent functions defined in
   kernel/arch/$(ARCH)/*.c but used in kernel/ are in kernel/proto.h
 . /etc/make.conf included in makefiles and shell scripts that need to
   know the building architecture; it defines ARCH=<arch>, currently only
   i386.
 . some basic per-architecture build support outside of the kernel (lib)
 . in clock.c, only dequeue a process if it was ready
 . fixes for new include files

files deleted:
 . mpx/klib.s - only for choosing between mpx/klib86 and -386
 . klib86.s - only for 86

i386-specific files files moved (or arch-dependent stuff moved) to arch/i386/:
 . mpx386.s (entry point)
 . klib386.s
 . sconst.h
 . exception.c
 . protect.c
 . protect.h
 . i8269.c
2006-12-22 15:22:27 +00:00

58 lines
1.8 KiB
C

/* The kernel call implemented in this file:
* m_type: SYS_SEGCTL
*
* The parameters for this kernel call are:
* m4_l3: SEG_PHYS (physical base address)
* m4_l4: SEG_SIZE (size of segment)
* m4_l1: SEG_SELECT (return segment selector here)
* m4_l2: SEG_OFFSET (return offset within segment here)
* m4_l5: SEG_INDEX (return index into remote memory map here)
*/
#include "../system.h"
#if USE_SEGCTL
/*===========================================================================*
* do_segctl *
*===========================================================================*/
PUBLIC int do_segctl(m_ptr)
register message *m_ptr; /* pointer to request message */
{
/* Return a segment selector and offset that can be used to reach a physical
* address, for use by a driver doing memory I/O in the A0000 - DFFFF range.
*/
u32_t selector;
vir_bytes offset;
int i, index;
register struct proc *rp;
phys_bytes phys = (phys_bytes) m_ptr->SEG_PHYS;
vir_bytes size = (vir_bytes) m_ptr->SEG_SIZE;
int result;
/* First check if there is a slot available for this segment. */
rp = proc_addr(who_p);
index = -1;
for (i=0; i < NR_REMOTE_SEGS; i++) {
if (! rp->p_priv->s_farmem[i].in_use) {
index = i;
rp->p_priv->s_farmem[i].in_use = TRUE;
rp->p_priv->s_farmem[i].mem_phys = phys;
rp->p_priv->s_farmem[i].mem_len = size;
break;
}
}
if (index < 0) return(ENOSPC);
offset = alloc_remote_segment(&selector, &rp->p_seg,
i, phys, size, USER_PRIVILEGE);
result = OK;
/* Request successfully done. Now return the result. */
m_ptr->SEG_INDEX = index | REMOTE_SEG;
m_ptr->SEG_SELECT = selector;
m_ptr->SEG_OFFSET = offset;
return(result);
}
#endif /* USE_SEGCTL */