X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fm68k%2Fq40%2FREADME;h=6bdbf4879570543bf052d8f35ec80644009a15ff;hb=4e4f43fe003969bdaa246374b90e16708a22ef79;hp=79a46b054d00af5a7ada2acde35c9504e2c87f46;hpb=86090fcac5e27b630656fe3d963a6b80e26dac44;p=linux-2.6.git diff --git a/arch/m68k/q40/README b/arch/m68k/q40/README index 79a46b054..6bdbf4879 100644 --- a/arch/m68k/q40/README +++ b/arch/m68k/q40/README @@ -9,18 +9,18 @@ and mirrors. Hints to documentation usually refer to the linux source tree in /usr/src/linux/Documentation unless URL given. -It seems IRQ unmasking can't be safely done on a Q40. IRQ probing +It seems IRQ unmasking can't be safely done on a Q40. IRQ probing is not implemented - do not try it! (See below) For a list of kernel command-line options read the documentation for the particular device drivers. The floppy imposes a very high interrupt load on the CPU, approx 30K/s. -When something blocks interrupts (HD) it will lose some of them, so far +When something blocks interrupts (HD) it will lose some of them, so far this is not known to have caused any data loss. On highly loaded systems -it can make the floppy very slow or practically stop. Other Q40 OS' simply +it can make the floppy very slow or practically stop. Other Q40 OS' simply poll the floppy for this reason - something that can't be done in Linux. -Only possible cure is getting a 82072 controller with fifo instead of +Only possible cure is getting a 82072 controller with fifo instead of the 8272A. drivers used by the Q40, apart from the very obvious (console etc.): @@ -28,7 +28,7 @@ drivers used by the Q40, apart from the very obvious (console etc.): serial.c # normal PC driver - any speed lp.c # printer driver genrtc.c # RTC - char/joystick/* # most of this should work, not + char/joystick/* # most of this should work, not # in default config.in block/q40ide.c # startup for ide ide* # see Documentation/ide.txt @@ -41,30 +41,30 @@ drivers used by the Q40, apart from the very obvious (console etc.): sound/dmasound_core.c dmasound_q40.c -Various other PC drivers can be enabled simply by adding them to +Various other PC drivers can be enabled simply by adding them to arch/m68k/config.in, especially 8 bit devices should be without any -problems. For cards using 16bit io/mem more care is required, like +problems. For cards using 16bit io/mem more care is required, like checking byte order issues, hacking memcpy_*_io etc. Debugging ========= -Upon startup the kernel will usually output "ABCQGHIJ" into the SRAM, -preceded by the booter signature. This is a trace just in case something -went wrong during earliest setup stages of head.S. -**Changed** to preserve SRAM contents by default, this is only done when -requested - SRAM must start with '%LX$' signature to do this. '-d' option +Upon startup the kernel will usually output "ABCQGHIJ" into the SRAM, +preceded by the booter signature. This is a trace just in case something +went wrong during earliest setup stages of head.S. +**Changed** to preserve SRAM contents by default, this is only done when +requested - SRAM must start with '%LX$' signature to do this. '-d' option to 'lxx' loader enables this. SRAM can also be used as additional console device, use debug=mem. -This will save kernel startup msgs into SRAM, the screen will display +This will save kernel startup msgs into SRAM, the screen will display only the penguin - and shell prompt if it gets that far.. Unfortunately only 2000 bytes are available. Serial console works and can also be used for debugging, see loader_txt -Most problems seem to be caused by fawlty or badly configured io-cards or +Most problems seem to be caused by fawlty or badly configured io-cards or hard drives anyway. Make sure to configure the parallel port as SPP and remove IRQ/DMA jumpers for first testing. The Q40 does not support DMA and may have trouble with @@ -74,7 +74,7 @@ parallel ports version of interrupts. Q40 Hardware Description ======================== -This is just an overview, see asm-m68k/* for details ask if you have any +This is just an overview, see asm-m68k/* for details ask if you have any questions. The Q40 consists of a 68040@40 MHz, 1MB video RAM, up to 32MB RAM, AT-style @@ -82,16 +82,16 @@ keyboard interface, 1 Programmable LED, 2x8bit DACs and up to 1MB ROM, 1MB shadow ROM. The Q60 has any of 68060 or 68LC060 and up to 128 MB RAM. -Most interfacing like floppy, IDE, serial and parallel ports is done via ISA -slots. The ISA io and mem range is mapped (sparse&byteswapped!) into separate +Most interfacing like floppy, IDE, serial and parallel ports is done via ISA +slots. The ISA io and mem range is mapped (sparse&byteswapped!) into separate regions of the memory. -The main interrupt register IIRQ_REG will indicate whether an IRQ was internal +The main interrupt register IIRQ_REG will indicate whether an IRQ was internal or from some ISA devices, EIRQ_REG can distinguish up to 8 ISA IRQs. The Q40 custom chip is programmable to provide 2 periodic timers: - 50 or 200 Hz - level 2, !!THIS CANT BE DISABLED!! - - 10 or 20 KHz - level 4, used for dma-sound - + - 10 or 20 KHz - level 4, used for dma-sound + Linux uses the 200 Hz interrupt for timer and beep by default. @@ -112,7 +112,7 @@ q40ints.c now contains a trivial hack for (a), (b) is more difficult because only irq's 4-15 can be disabled - and only all of them at once. Thus disable_irq() can effectively block the machine if the driver goes asleep. -One thing to keep in mind when hacking around the interrupt code is +One thing to keep in mind when hacking around the interrupt code is that there is no way to find out which IRQ caused a request, [EI]IRQ_REG displays current state of the various IRQ lines. @@ -123,11 +123,11 @@ q40 receives AT make/break codes from the keyboard, these are translated to the PC scancodes x86 Linux uses. So by theory every national keyboard should work just by loading the appropriate x86 keytable - see any national-HOWTO. -Unfortunately the AT->PC translation isn't quite trivial and even worse, my -documentation of it is absolutely minimal - thus some exotic keys may not +Unfortunately the AT->PC translation isn't quite trivial and even worse, my +documentation of it is absolutely minimal - thus some exotic keys may not behave exactly as expected. -There is still hope that it can be fixed completely though. If you encounter +There is still hope that it can be fixed completely though. If you encounter problems, email me ideally this: - exact keypress/release sequence - 'showkey -s' run on q40, non-X session