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/*
* -----------------------------------------------------------------------
*
* Copyright 1994-2009 H. Peter Anvin - All Rights Reserved
* Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, Inc., 53 Temple Place Ste 330,
* Boston MA 02111-1307, USA; either version 2 of the License, or
* (at your option) any later version; incorporated herein by reference.
*
* ----------------------------------------------------------------------- */
/*
* loadhigh.c
*
* An alternate interface to getfssec.
*
* Inputs: SI = file handle/cluster pointer
* EDI = target address in high memory
* EAX = maximum number of bytes to load
* DX = zero-padding mask (e.g. 0003h for pad to dword)
* BX = 16-bit subroutine to call at the top of each loop
* (to print status and check for abort)
* EBP = maximum load address
*
* Outputs: SI = file handle/cluster pointer
* EBX = first untouched address (not including padding)
* EDI = first untouched address (including padding)
* CF = reached EOF
* OF = ran out of high memory
*/
#include <com32.h>
#include <minmax.h>
#include "core.h"
#include "fs.h"
#define MAX_CHUNK (1 << 20) /* 1 MB */
void pm_load_high(com32sys_t *regs)
{
struct fs_info *fs;
uint32_t bytes;
uint32_t zero_mask;
bool have_more;
uint32_t bytes_read;
char *buf, *limit;
struct file *file;
uint32_t sector_mask;
size_t pad;
bytes = regs->eax.l;
zero_mask = regs->edx.w[0];
buf = (char *)regs->edi.l;
limit = (char *)(regs->ebp.l & ~zero_mask);
file = handle_to_file(regs->esi.w[0]);
fs = file->fs;
regs->eflags.l &= ~(EFLAGS_CF|EFLAGS_OF|EFLAGS_AF|
EFLAGS_PF|EFLAGS_ZF|EFLAGS_SF);
sector_mask = SECTOR_SIZE(fs) - 1;
while (bytes) {
uint32_t sectors;
uint32_t chunk;
if (buf + SECTOR_SIZE(fs) > limit) {
/* Can't fit even one more sector in... */
regs->eflags.l |= EFLAGS_OF;
break;
}
chunk = bytes;
if (regs->ebx.w[0]) {
call16((void (*)(void))(size_t)regs->ebx.w[0], &zero_regs, NULL);
chunk = min(chunk, MAX_CHUNK);
}
if (chunk > (((char *)limit - buf) & ~sector_mask))
chunk = ((char *)limit - buf) & ~sector_mask;
sectors = (chunk + sector_mask) >> SECTOR_SHIFT(fs);
bytes_read = fs->fs_ops->getfssec(file, buf, sectors, &have_more);
if (bytes_read > chunk)
bytes_read = chunk;
buf += bytes_read;
bytes -= bytes_read;
if (!have_more) {
/*
* If we reach EOF, the filesystem driver will have already closed
* the underlying file... this really should be cleaner.
*/
_close_file(file);
regs->esi.w[0] = 0;
regs->eflags.l |= EFLAGS_CF;
break;
}
}
pad = (size_t)buf & zero_mask;
if (pad)
memset(buf, 0, pad);
regs->ebx.l = (size_t)buf;
regs->edi.l = (size_t)buf + pad;
}
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