On Tue, 1 Apr 2014, Geert Uytterhoeven wrote: > On Tue, Apr 1, 2014 at 1:52 AM, Michael Schmitz wrote: > > > > do we know the size of the first memory chunk early enough in > > > > head.S? Maybe it's time to increase INIT_MAPPED_SIZE at least in > > > > cases where we know that there's more than 4 MB in the first > > > > memchunk ... > > > > > > How do you know? You would have to reimplement the check > > > paging_init does. > > > > I see - as a heuristic, we can probably assume that the first memchunk > > is the relevant one, and especially in the case of FastRAM, also the > > larger one. Does this hold for Amiga/Mac/VME as well? > > People want to run the kernel in the fastest memory chunk, which is > typically also the largest (slow Amiga mainboard memory may be 2 - 16 > MiB for Linux-capable machines, accelerator memory may be larger). > > Don't know about Mac,
It may be possible to boot Linux with MacOS running in 24-bit mode, and ISTR that this leads to a large number of memory chunks. The Penguin documentation says use 32-bit mode (which means installing Mode32 if you have old MacOS and old ROMs). The only Mac I have here is running MacOS 7.6 so I can't test 24-bit mode. You can see the debug output from Penguin below. > but I have some memories of interleaved banks and such... There are some Mac models with memory controllers that do interleaving. I don't know whether interleaving is relevant here. I'd have to consult the Penguin source code to know whether it behaves differently on different models. Perhaps you're thinking of this -- "68020: Don't force kernel into bank A: [optional] This is a special option for the 68020 and MacII owners only. It has to do with the physical arrangement of the memory banks in the MacII ... NOTE: This option has been removed from Penguin 18." from http://www.mac.linux-m68k.org/docs/penguin.php -- Logging started Friday, 1 January 1904 12:19:07 AM Penguin App version 19 Logical To Physical Mapping table (V2) Logical -> physical : length 0x00000000 -> 0x00000000 : 0x00C00000 System: 7.6.1 Gestalt ID: 33 (PowerBook 180) CPU: 68030 FPU: 68882 Physical RAM: 12 MB Command line is 'consoleblank=0 console=tty console=ttyS0 earlyprintk' GUnzipping Macintosh HD:Desktop Folder:vmlinux.gz .Kernel format: ELF The kernel will be located at physical 0x00001000 Kernel at logical address 0x5d4008 GUnzipping Macintosh HD:Desktop Folder:vmlinux.gz ..............................................Read 2794880 bytes for segment 0, requested 2794880 .Read 101752 bytes for segment 1, requested 101752 Bootstrap's bootinfo version: 2.0 Kernel's bootinfo version : 2.0 Kernel entry physical is 0x2000 RAM disk at 0x008b7008, ends at 0x00929008, size is 456 K Kernel segment 0 at 0x5d4008, size 2917724 Kernel segment 1 at 0x89d008, size 102400 Kernel size is 0x2e2000 boot_info is at 0x8b6008 boot_info size is dynamic ramdisk logical target 0xb8e000 ramdisk physical at 0xb8e000 ramdisk physical top at 0xc00000 Bootstrap logical 1: 0x00000000 Bootstrap physical : 0x00000000 Dump of bootinfo, version 2.0: BI_MACHTYPE = 0x3 BI_CPUTYPE = 0x2 BI_FPUTYPE = 0x2 BI_MMUTYPE = 0x2 BI_MEMCHUNK[0].addr = 0x00000000 BI_MEMCHUNK[0].size = 0x00c00000 BI_RAMDISK.addr = 0x00b8e000 BI_RAMDISK.size = 0x00072000 BI_COMMAND_LINE = consoleblank=0 console=tty console=ttyS0 earlyprintk BI_MAC_MODEL = 0x21 BI_MAC_VADDR = 0x60040000 BI_MAC_VDEPTH = 0x4 BI_MAC_VROW = 0x140 BI_MAC_VDIM = 0x01900280 BI_MAC_VLOGICAL = 0x60040000 BI_MAC_SCCBASE = 0x50f04000 BI_MAC_BTIME = 0x83da53fb BI_MAC_GMTBIAS = 0x0 BI_MAC_MEMSIZE = 0xc BI_MAC_CPUID = 0x1 BI_MAC_ROMBASE = 0x40800000 Booting Linux (fasten seat belts, please)... Waking up serial ports, no rest for the wicked... Modem port awake and configured! slot_int_set: slot 0x00, drvr_refnum -49, spID 0xBC, spExtDev 0x00, ON 0 Logging ended Friday, 1 January 1904 12:19:50 AM -- To unsubscribe from this list: send the line "unsubscribe linux-m68k" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html