diff options
Diffstat (limited to 'ldlinux.asm')
| -rw-r--r-- | ldlinux.asm | 45 |
1 files changed, 32 insertions, 13 deletions
diff --git a/ldlinux.asm b/ldlinux.asm index dc77df86..5eca9ec6 100644 --- a/ldlinux.asm +++ b/ldlinux.asm @@ -1619,8 +1619,6 @@ kernel_sane: push ax jc kernel_corrupt ; Failure in first 32K cmp word [es:bs_bootsign],0AA55h jne kernel_corrupt ; Boot sec signature missing - cmp byte [es:su_jump],0EBh ; Jump opcode - jne kernel_corrupt ; ; Get the BIOS' idea of what the size of high memory is ; @@ -1666,7 +1664,7 @@ hms_ok: mov [HighMemSize],ax ; mov si,cmd_line_here mov byte [initrd_flag],0 - push es + push es ; Set DS <- real_mode_seg pop ds get_next_opt: lodsb and al,al @@ -1679,8 +1677,8 @@ get_next_opt: lodsb je is_vga_cmd cmp eax,'mem=' je is_mem_cmd - push es ; Save ES->real_mode_seg - push cs + push es ; Save ES -> real_mode_seg + push ss pop es ; Set ES <- normal DS mov di,initrd_cmd mov cx,initrd_cmd_len @@ -1692,7 +1690,7 @@ get_next_opt: lodsb pop si cmp byte [es:InitRD],' ' ; Null filename? seta byte [es:initrd_flag] ; Set flag if not -not_initrd: pop es ; Restore ES->real_mode_seg +not_initrd: pop es ; Restore ES -> real_mode_seg skip_this_opt: lodsb ; Load from command line cmp al,' ' ja skip_this_opt @@ -1724,10 +1722,10 @@ is_mem_cmd: cmp ebx,14*1024 ; Only trust < 15M point jna memcmd_fair mov bx,14*1024 -memcmd_fair: mov [es:HighMemSize],bx +memcmd_fair: mov [ss:HighMemSize],bx jmp short skip_this_opt cmdline_end: - push cs ; Restore standard DS + push ss ; Restore standard DS pop ds ; ; Now check if we have a large kernel, which needs to be loaded high @@ -1739,7 +1737,7 @@ cmdline_end: cmp word [es:su_version],0201h ; Version 2.01+? jb new_kernel ; If 2.00, skip this step mov word [es:su_heapend],linux_stack ; Set up the heap - or byte [es:su_loadflags],80h ; Let the kernel know we cared + or byte [es:su_loadflags],80h ; Let the kernel know we care ; ; We definitely have a new-style kernel. Let the kernel know who we are, ; and that we are clueful @@ -1866,6 +1864,26 @@ high_load_done: call cwritestr ; ; Abandon hope, ye that enter here! We do no longer permit aborts. +; + call abort_check ; Last chance!! + +; +; Some kernels in the 1.2 ballpark but pre-bzImage have more than 4 +; setup sectors, but the boot protocol had not yet been defined. They +; rely on a signature to figure out if they need to copy stuff from +; the "protected mode" kernel area. Unfortunately, we used that area +; as a transfer buffer, so it's going to find the signature there. +; Hence, zero the low 32K beyond the setup area. +; + mov di,[SetupSecs] + inc di ; Setup + boot sector + mov cx,32768/512 ; Sectors/32K + sub cx,di ; Remaining sectors + shl di,9 ; Sectors -> bytes + shl cx,7 ; Sectors -> dwords + xor eax,eax + rep stosd ; Clear region +; ; Now, if we were supposed to load "low", copy the kernel down to 10000h ; test byte [LoadFlags],LOAD_HIGH @@ -1889,7 +1907,8 @@ root_not_floppy: ; Copy the disk table to high memory, then re-initialize the floppy ; controller ; - mov si,floppy_table + push ds + lds si,[fdctab] mov di,linux_fdctab mov cx,3 ; 12 bytes push di @@ -1902,6 +1921,7 @@ root_not_floppy: xor ax,ax xor dx,dx int 13h + pop ds ; ; Linux wants the floppy motor shut off before starting the kernel, ; at least bootsect.S seems to imply so @@ -1914,7 +1934,6 @@ kill_motor: ; Now we're as close to be done as we can be and still use our normal ; routines, print a CRLF to end the row of dots ; - call abort_check ; Last chance!! mov si,crlf call writestr ; @@ -1952,7 +1971,7 @@ old_kernel: load_old_kernel: mov word [SetupSecs],4 ; Always 4 setup sectors mov byte [LoadFlags],0 ; Always low - jmp load_kernel + jmp read_kernel ; ; cwritestr: write a null-terminated string to the console, saving ; registers on entry (we can't use this in the boot sector, @@ -2995,7 +3014,7 @@ copyright_str db ' Copyright (C) 1994-', year, ' H. Peter Anvin' boot_prompt db 'boot: ',0 wipe_char db 08h, ' ', 08h, 0 err_notfound db 'Could not find kernel image: ',0 -err_notkernel db 0Dh, 0Ah, 'Invalid or corrupt kernel image: ',0 +err_notkernel db 0Dh, 0Ah, 'Invalid or corrupt kernel image: ', 0 err_not386 db 'It appears your computer uses a 286 or lower CPU.' db 0Dh, 0Ah db 'You cannot run Linux unless you have a 386 or higher CPU' |