From 4f2568ba84172915df94995df4ad358d2f09cc0e Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Fri, 14 May 2010 15:22:00 -0700 Subject: [PATCH] core: fix "sector size" confusion Fix the case where the "sector size" used by the pm filesystem driver isn't the same thing as the SECTOR_SIZE/SECTOR_SHIFT macros used in the assembly code. This is a per-device property, and in the particular case of isolinux hybrid, they are not even currently the same (for all others, they are the same for now, but not necessarily in the future.) Signed-off-by: H. Peter Anvin --- core/comboot.inc | 8 ++++---- core/diskfs.inc | 9 --------- core/extern.inc | 4 +++- core/fs/fs.c | 35 ++++++++++++++++++++++++++++++++++- core/fs/iso9660/iso9660.c | 4 ++-- core/getc.inc | 5 ++--- core/isolinux.asm | 19 ------------------- core/pxelinux.asm | 11 ----------- core/runkernel.inc | 4 ++-- 9 files changed, 47 insertions(+), 52 deletions(-) diff --git a/core/comboot.inc b/core/comboot.inc index 9255f8a..b714dd4 100644 --- a/core/comboot.inc +++ b/core/comboot.inc @@ -124,9 +124,8 @@ is_comboot_image: ; Now actually load the file... pop si ; File handle mov bx,100h ; Load at :0100h - mov cx,10000h >> SECTOR_SHIFT - ; Absolute maximum # of sectors - pm_call getfssec + mov cx,0FF00h ; Maximum number of bytes + pm_call getfsbytes cmp ecx,65536-256-2 ; Maximum size ja comboot_too_large @@ -586,7 +585,8 @@ comapi_derinfo: %else ; Physical medium... - mov P_CL,SECTOR_SHIFT + mov al,[SectorShift] + mov P_CL,al mov al,[DriveNumber] mov P_DL,al mov P_FS,cs diff --git a/core/diskfs.inc b/core/diskfs.inc index b8d0376..9f18c76 100644 --- a/core/diskfs.inc +++ b/core/diskfs.inc @@ -171,12 +171,3 @@ exten_table_end: %ifdef debug ; This code for debugging only debug_magic dw 0D00Dh ; Debug code sentinel %endif - - alignz 4 -BufSafe dw trackbufsize/SECTOR_SIZE ; Clusters we can load into trackbuf -BufSafeBytes dw trackbufsize ; = how many bytes? -%ifndef DEPEND -%if ( trackbufsize % SECTOR_SIZE ) != 0 -%error trackbufsize must be a multiple of SECTOR_SIZE -%endif -%endif diff --git a/core/extern.inc b/core/extern.inc index 6110db0..64edea6 100644 --- a/core/extern.inc +++ b/core/extern.inc @@ -10,8 +10,10 @@ extern rllpack, rllunpack ; fs.c - extern fs_init, pm_searchdir, getfssec, pm_mangle_name, load_config + extern fs_init, pm_searchdir, getfssec, getfsbytes + extern pm_mangle_name, load_config extern pm_open_file, pm_close_file + extern SectorSize, SectorShift ; chdir.c extern pm_realpath diff --git a/core/fs/fs.c b/core/fs/fs.c index 792da02..3ae12ec 100644 --- a/core/fs/fs.c +++ b/core/fs/fs.c @@ -117,6 +117,35 @@ void getfssec(com32sys_t *regs) regs->ecx.l = bytes_read; } +void getfsbytes(com32sys_t *regs) +{ + int sectors; + bool have_more; + uint32_t bytes_read; + char *buf; + struct file *file; + uint16_t handle; + + handle = regs->esi.w[0]; + file = handle_to_file(handle); + + sectors = regs->ecx.w[0] >> SECTOR_SHIFT(file->fs); + + buf = MK_PTR(regs->es, regs->ebx.w[0]); + bytes_read = file->fs->fs_ops->getfssec(file, buf, sectors, &have_more); + + /* + * If we reach EOF, the filesystem driver will have already closed + * the underlying file... this really should be cleaner. + */ + if (!have_more) { + _close_file(file); + regs->esi.w[0] = 0; + } + + regs->ecx.l = bytes_read; +} + size_t pmapi_read_file(uint16_t *handle, void *buf, size_t sectors) { bool have_more; @@ -353,8 +382,9 @@ void pm_close_file(com32sys_t *regs) * invoke the fs-specific init function; * initialize the cache if we need one; * finally, get the current inode for relative path looking. - * */ +__bss16 uint16_t SectorSize, SectorShift; + void fs_init(com32sys_t *regs) { static struct fs_info fs; /* The actual filesystem buffer */ @@ -411,4 +441,7 @@ void fs_init(com32sys_t *regs) fs.root = fs.fs_ops->iget_root(&fs); fs.cwd = get_inode(fs.root); } + + SectorShift = fs.sector_shift; + SectorSize = fs.sector_size; } diff --git a/core/fs/iso9660/iso9660.c b/core/fs/iso9660/iso9660.c index 4c568bf..d695e43 100644 --- a/core/fs/iso9660/iso9660.c +++ b/core/fs/iso9660/iso9660.c @@ -206,8 +206,8 @@ static struct inode *iso_get_inode(struct fs_info *fs, inode->blocks = (inode->size + BLOCK_SIZE(fs) - 1) >> BLOCK_SHIFT(fs); /* We have a single extent for all data */ - inode->next_extent.pstart = de->extent_le << blktosec; - inode->next_extent.len = inode->blocks << blktosec; + inode->next_extent.pstart = (sector_t)de->extent_le << blktosec; + inode->next_extent.len = (sector_t)inode->blocks << blktosec; return inode; } diff --git a/core/getc.inc b/core/getc.inc index efe60de..33656b4 100644 --- a/core/getc.inc +++ b/core/getc.inc @@ -23,7 +23,6 @@ MAX_GETC_LG2 equ 4 ; Max number of file nesting MAX_GETC equ (1 << MAX_GETC_LG2) bytes_per_getc_lg2 equ 16-MAX_GETC_LG2 bytes_per_getc equ (1 << bytes_per_getc_lg2) -secs_per_getc equ bytes_per_getc/SECTOR_SIZE MAX_UNGET equ 9 ; Max bytes that can be pushed back struc getc_file @@ -135,8 +134,8 @@ getc: and si,si mov [di+gc_bufbytes],si ; In case SI == 0 jz .empty - mov cx,bytes_per_getc >> SECTOR_SHIFT - pm_call getfssec + mov cx,bytes_per_getc + pm_call getfsbytes mov [di+gc_bufbytes],cx mov [di+gc_file],si jcxz .empty diff --git a/core/isolinux.asm b/core/isolinux.asm index d2ba81d..8060767 100644 --- a/core/isolinux.asm +++ b/core/isolinux.asm @@ -1379,22 +1379,3 @@ img_table: db 80-1 ; Max cylinder db 36 ; Max sector db 2-1 ; Max head - -; -; Misc initialized (data) variables -; - -; -; Variables that are uninitialized in SYSLINUX but initialized here -; -; **** ISOLINUX:: We may have to make this flexible, based on what the -; **** BIOS expects our "sector size" to be. -; - alignz 4 -BufSafe dw trackbufsize/SECTOR_SIZE ; Clusters we can load into trackbuf -BufSafeBytes dw trackbufsize ; = how many bytes? -%ifndef DEPEND -%if ( trackbufsize % SECTOR_SIZE ) != 0 -%error trackbufsize must be a multiple of SECTOR_SIZE -%endif -%endif diff --git a/core/pxelinux.asm b/core/pxelinux.asm index 204b09c..0b87e73 100644 --- a/core/pxelinux.asm +++ b/core/pxelinux.asm @@ -534,14 +534,3 @@ KeepPXE db 0 ; Should PXE be kept around? alignz 4 global MyIP MyIP dd 0 ; My IP address -; -; Variables that are uninitialized in SYSLINUX but initialized here -; - alignz 4 -BufSafe dw trackbufsize/TFTP_BLOCKSIZE ; Clusters we can load into trackbuf -BufSafeBytes dw trackbufsize ; = how many bytes? -%ifndef DEPEND -%if ( trackbufsize % TFTP_BLOCKSIZE ) != 0 -%error trackbufsize must be a multiple of TFTP_BLOCKSIZE -%endif -%endif diff --git a/core/runkernel.inc b/core/runkernel.inc index bf67b11..25b073f 100644 --- a/core/runkernel.inc +++ b/core/runkernel.inc @@ -55,10 +55,10 @@ is_linux_kernel: ; work since we might have funny stuff up near the end of memory). ; call abort_check ; Check for abort key - mov cx,8000h >> SECTOR_SHIFT ; Half a moby (32K) + mov cx,8000h ; Half a moby (32K) xor bx,bx pop si ; file pointer - pm_call getfssec + pm_call getfsbytes cmp cx,1024 jb kernel_corrupt cmp word [es:bs_bootsign],0AA55h -- 2.7.4