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Diffstat (limited to 'doc/README.nios')
| -rw-r--r-- | doc/README.nios | 98 |
1 files changed, 82 insertions, 16 deletions
diff --git a/doc/README.nios b/doc/README.nios index aee0ecd..8765df7 100644 --- a/doc/README.nios +++ b/doc/README.nios @@ -1,12 +1,27 @@ U-Boot for Nios-32 - Last Update: October 15, 2003 + Last Update: November 30, 2003 ==================================================================== This file contains information regarding U-Boot and the Altera Nios CPU. For information regarding U-Boot and the Nios Development -Kit, Cyclone Edition (DK-1C20), see doc/README.dk1c20. +Kits see: + + * Cyclone Edition (DK-1C20), see doc/README.dk1c20 + * Stratix Edition (DK-1S10), see doc/README.dk1s10 (TODO) + * Stratix Edition (DK-1S40), see doc/README.dk1s40 (TODO) + * Stratix Edition (DK-20K200), see doc/README.dk20k200 (TODO) + +For informations regarding Nios Development Kit hardware overview +and the NIOS CPU standard configuration of all known boards made by +Altera see: + + * Development Kit (DK) hardware overview, see doc/README.nios_DK + * NIOS CPU standard_32 at DK-1C20, see doc/README.dk1c20_std32 + * NIOS CPU standard_32 at DK-1S10, see doc/README.dk1s10_std32 + * NIOS CPU standard_32 at DK-1S40, see doc/README.dk1s40_std32 + * NIOS CPU standard_32 at DK-20K200, see doc/README.dk20k200_std32 For those interested in contributing ... see HELP WANTED below. @@ -50,16 +65,25 @@ structure definitions from the Nios SDK. 2.1 Nios-specific Options/Settings ----------------------------------- All configuration options/settings that are specific to Nios begin -with "CONFIG_NIOS_" or "CFG_NIOS_". The following is a list of -currently defined Nios-specific options/parameters. If any options -are related to Standard-32 Nios SDK excalibur.h definitions, the -related definition follows the description). +with "CONFIG_NIOS_", "CFG_NIOS_", or "CFG_NIOS_CPU_". + +The configuration follows a two-stage process. In the first stage +the NIOS CPU core will defined like defined in Alteras SOPC Builder. +At this point we use the "CFG_NIOS_CPU_" defines exclusively. For +more informations about all the definitions you have to setup see +into current board configurations and doc/README.nios_CFG_NIOS_CPU. +In second stage we bring the NIOS CPU configuration in relation to +U-Boot configuration options/settings. The following is a list of +currently defined Nios-specific options/parameters used inside of +U-Boot. If any options are related to Standard-32 Nios SDK +excalibur.h definitions, the related definition follows the +description). CONFIG_NIOS -- defined for all Nios-32 boards. CFG_NIOS_CONSOLE -- the base address of the console UART. - (standard-32: na_uart1_base). + (standard-32: nasys_uart_0 resp. na_uart1_base). CFG_NIOS_FIXEDBAUD -- defined if the console UART PTF fixed_baud parameter is set to '1'. @@ -71,10 +95,11 @@ CFG_NIOS_MULT_MSTEP -- use hardware assisted multiply using the CFG_NIOS_TMRBASE -- the base address of the timer used to support xxx_timer routines (e.g. set_timer(), get_timer(), etc.). - (standard-32: na_lo_priority_timer2_base). + (standard-32: nasys_timer_1 resp. na_lo_priority_timer2_base). CFG_NIOS_TMRIRQ -- the interrupt request (vector number) assigned to - the timer. (standard-32: na_low_priority_timer2_irq). + the timer. (standard-32: nasys_timer_1_irq resp. + na_low_priority_timer2_irq). CFG_NIOS_TMRMS -- the period of the timer in milliseconds. @@ -105,20 +130,56 @@ is an alias for 'subi %rB,1' that is supported by the assembler but does not appear in the programmer's manual. -4. BRAIN DAMAGE +4. BOOT PROCESS +--------------- + +4.1 Boot process over GERMS +--------------------------- +When the NIOS CPU catch a reset signal it will begin to be running +code from CFG_NIOS_CPU_RST_VECT. Normally at this place it will +find the GERMS monitor. That's the case for the generic NIOS CPU +configuration "standard_32". When the GERMS monitor starts running, +it performs important system initializations and then looks for +executable code in flash, using the following steps: + + 1. Examining the two bytes at CFG_NIOS_CPU_FLASH_BASE + 0x04000C. + 2. Examining the button 0 on the PIO CFG_NIOS_CPU_BUTTON_PIO. + 3. If the button is not pressed and the two bytes contain 'N' + and 'i', the monitor executes a CALL to location + CFG_NIOS_CPU_FLASH_BASE + 0x040000. + 4. If the code is not executed in step 3 or the code returns, + then prints an 8-digit version number to STDOUT and waits for + user commands from STDIN. + +In normal case, for "standard_32", STDIN and STDOUT are the first +serial port. + +4.2 Return to GERMS command line +-------------------------------- +During the boot process, the GERMS monitor checks for the existence +of application software in flash memory. If found, the processor +immediately executes the code. To return program execution to the +GERMS monitor (that is, avoid running code stored in flash memory): + + 1. Hold down CFG_NIOS_CPU_BUTTON_PIO, button number 0. + 2. Press then release the CPU reset button. + 3. Release CFG_NIOS_CPU_BUTTON_PIO, button number 0. + + +5. BRAIN DAMAGE ---------------- This section describes some of the unfortunate and avoidable aspects of working with the Nios CPU ... and some things you can do to reduce your pain. -4.1 GERMS doesn't work with Hyperterminal +5.1 GERMS doesn't work with Hyperterminal ------------------------------------------ GERMS doesn't do CR/LF mapping that is compatible with Hyperterminal (or minicom) -- geez. Regardless of you opion of Hyperterminal, this sad design decision is remedied by using U-Boot. -4.2 cygwin Incompatibility +5.2 cygwin Incompatibility --------------------------- The version of cygwin distributed with the nios GNUPro toolchain is out-of-date and incompatible with the latest cygwin distributions. @@ -131,7 +192,7 @@ topic). The solution ... well, you can wait for Altera ... or build as set of tools for linux. -4.3 No native gcc +5.3 No native gcc ------------------ I'm not sure how this one slipped through the cracks ... but it is a real pain. Basically, if you want to build anything for the native @@ -140,9 +201,11 @@ and the old version of cygwin makes locating one challenging. The solution ... same as above. Just download the gcc source from Altera and build up a set of cross tools for your favorite linux -distro. +distro. Anybody who wants to use an already precompiled NIOS cross +toolchain can it found in the CDK4NIOS project hosted by Source +Forge at http://cdk4nios.sourceforge.net. -4.4 Can't build default U-Boot +5.4 Can't build default U-Boot ------------------------------- By default, when you build U-Boot you will be building some native tools along with the target elf, bin, and srec files. Without a @@ -167,7 +230,7 @@ environment.o: environment.c ../tools/envcrc BTW, thats a 'zero' ... not the letter 'O'. -5. HELP WANTED +6. HELP WANTED --------------- There are plenty of areas where help is needed. Here's are some ideas @@ -190,3 +253,6 @@ Regards, --Scott <smcnutt@psyent.com> + +--Stephan +<linz@li-pro.net> |