1 /* 2 * ----------------------------------------------------------------------- 3 * 4 * Copyright 1994-2009 H. Peter Anvin - All Rights Reserved 5 * Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation, Inc., 53 Temple Place Ste 330, 10 * Boston MA 02111-1307, USA; either version 2 of the License, or 11 * (at your option) any later version; incorporated herein by reference. 12 * 13 * ----------------------------------------------------------------------- */ 14 15 /* 16 * loadhigh.c 17 * 18 * An alternate interface to getfssec. 19 * 20 * Inputs: SI = file handle/cluster pointer 21 * EDI = target address in high memory 22 * EAX = maximum number of bytes to load 23 * DX = zero-padding mask (e.g. 0003h for pad to dword) 24 * BX = 16-bit subroutine to call at the top of each loop 25 * (to print status and check for abort) 26 * EBP = maximum load address 27 * 28 * Outputs: SI = file handle/cluster pointer 29 * EBX = first untouched address (not including padding) 30 * EDI = first untouched address (including padding) 31 * CF = reached EOF 32 * OF = ran out of high memory 33 */ 34 35 #include <com32.h> 36 #include <minmax.h> 37 #include "core.h" 38 #include "fs.h" 39 40 #define MAX_CHUNK (1UL << 20) /* 1 MB */ 41 42 void pm_load_high(com32sys_t *regs) 43 { 44 struct fs_info *fs; 45 uint32_t bytes; 46 uint32_t zero_mask; 47 bool have_more; 48 uint32_t bytes_read; 49 char *buf, *limit; 50 struct file *file; 51 uint32_t sector_mask; 52 size_t pad; 53 uint32_t retflags = 0; 54 55 bytes = regs->eax.l; 56 zero_mask = regs->edx.w[0]; 57 buf = (char *)regs->edi.l; 58 limit = (char *)(regs->ebp.l & ~zero_mask); 59 file = handle_to_file(regs->esi.w[0]); 60 fs = file->fs; 61 62 sector_mask = SECTOR_SIZE(fs) - 1; 63 64 while (bytes) { 65 uint32_t sectors; 66 uint32_t chunk; 67 68 if (buf + SECTOR_SIZE(fs) > limit) { 69 /* Can't fit even one more sector in... */ 70 retflags = EFLAGS_OF; 71 break; 72 } 73 74 chunk = bytes; 75 76 if (regs->ebx.w[0]) { 77 call16((void (*)(void))(size_t)regs->ebx.w[0], &zero_regs, NULL); 78 chunk = min(chunk, MAX_CHUNK); 79 } 80 81 if (chunk > (((char *)limit - buf) & ~sector_mask)) 82 chunk = ((char *)limit - buf) & ~sector_mask; 83 84 sectors = (chunk + sector_mask) >> SECTOR_SHIFT(fs); 85 bytes_read = fs->fs_ops->getfssec(file, buf, sectors, &have_more); 86 87 if (bytes_read > chunk) 88 bytes_read = chunk; 89 90 buf += bytes_read; 91 bytes -= bytes_read; 92 93 if (!have_more) { 94 /* 95 * If we reach EOF, the filesystem driver will have already closed 96 * the underlying file... this really should be cleaner. 97 */ 98 _close_file(file); 99 regs->esi.w[0] = 0; 100 retflags = EFLAGS_CF; 101 break; 102 } 103 } 104 105 pad = (size_t)buf & zero_mask; 106 if (pad) 107 memset(buf, 0, pad); 108 109 regs->ebx.l = (size_t)buf; 110 regs->edi.l = (size_t)buf + pad; 111 set_flags(regs, retflags); 112 } 113
