Add Nios GDB/JTAG Console support: - Add stubs to support gdb via JTAG. - Add support for console over JTAG. - Minor cleanup.

diff -Naurb u-boot-2004APR25/CHANGELOG nios-jtag-gdb/CHANGELOG --- u-boot-2004APR25/CHANGELOG 2004-04-25 14:48:28.000000000 -0400 +++ nios-jtag-gdb/CHANGELOG 2004-04-25 17:48:56.000000000 -0400 @@ -2,6 +2,11 @@ Changes for U-Boot 1.1.1: ======================================================================

+* Add Nios GDB/JTAG Console support, Scott McNutt, 25 Apr 2004: + - Add stubs to support gdb via JTAG. + - Add support for console over JTAG. + - Minor cleanup. + * Clean up the TQM8xx_YYMHz configurations; allow to use the same binary image for all clok frequencies. Implement run-time optimization of flash access timing based on the actual bus diff -Naurb u-boot-2004APR25/board/altera/dk1c20/vectors.S nios-jtag-gdb/board/altera/dk1c20/vectors.S --- u-boot-2004APR25/board/altera/dk1c20/vectors.S 2004-01-03 14:43:48.000000000 -0500 +++ nios-jtag-gdb/board/altera/dk1c20/vectors.S 2004-04-25 16:27:21.000000000 -0400 @@ -38,6 +38,8 @@ * _cwp_lolimit -Handles register window underflows. * _cwp_hilimit -Handles register window overflows. * _timebase_int -Increments the timebase. + * _brkpt_hw_int -Hardware breakpoint handler. + * _brkpt_sw_int -Software breakpoint handler. * _def_xhandler -Default exception handler. * * _timebase_int handles a Nios Timer interrupt and increments the @@ -58,9 +60,8 @@ .long _def_xhandler@h /* Vector 0 - NMI */ .long _cwp_lolimit@h /* Vector 1 - underflow */ .long _cwp_hilimit@h /* Vector 2 - overflow */ - - .long _def_xhandler@h /* Vector 3 - GNUPro debug */ - .long _def_xhandler@h /* Vector 4 - GNUPro debug */ + .long _brkpt_hw_int@h /* Vector 3 - Breakpoint */ + .long _brkpt_sw_int@h /* Vector 4 - Single step*/ .long _def_xhandler@h /* Vector 5 - GNUPro debug */ .long _def_xhandler@h /* Vector 6 - future reserved */ .long _def_xhandler@h /* Vector 7 - future reserved */ diff -Naurb u-boot-2004APR25/config.mk nios-jtag-gdb/config.mk --- u-boot-2004APR25/config.mk 2004-03-13 18:29:44.000000000 -0500 +++ nios-jtag-gdb/config.mk 2004-04-25 19:23:54.000000000 -0400 @@ -126,7 +126,7 @@ # this option have to be placed behind -Wall -- that's why it is here ifeq ($(ARCH),nios) ifeq ($(findstring 2.9,$(shell $(CC) --version)),2.9) -CFLAGS := $(CPPFLAGS) -Wno-trigraphs +CFLAGS := $(CPPFLAGS) -Wall -Wno-trigraphs endif endif

diff -Naurb u-boot-2004APR25/cpu/nios/interrupts.c nios-jtag-gdb/cpu/nios/interrupts.c --- u-boot-2004APR25/cpu/nios/interrupts.c 2004-02-23 18:54:50.000000000 -0500 +++ nios-jtag-gdb/cpu/nios/interrupts.c 2004-04-25 15:44:11.000000000 -0400 @@ -179,7 +179,7 @@ int vec;

printf ("\nInterrupt-Information:\n"); - printf ("Nr Routine Arg CouIt's ok to cnt\n"); + printf ("Nr Routine Arg Count\n");

for (vec=0; vec<64; vec++) { if (irq_vecs[vec].handler != NULL) { diff -Naurb u-boot-2004APR25/cpu/nios/serial.c nios-jtag-gdb/cpu/nios/serial.c --- u-boot-2004APR25/cpu/nios/serial.c 2004-02-23 18:54:50.000000000 -0500 +++ nios-jtag-gdb/cpu/nios/serial.c 2004-04-25 16:10:06.000000000 -0400 @@ -26,6 +26,48 @@ #include <watchdog.h> #include <nios-io.h>

+/*------------------------------------------------------------------ + * JTAG acts as the serial port + *-----------------------------------------------------------------*/ +#if defined(CONFIG_CONSOLE_JTAG) + +static nios_jtag_t *jtag = (nios_jtag_t *)CFG_NIOS_CONSOLE; + +void serial_setbrg( void ){ return; } +int serial_init( void ) { return(0);} + +void serial_putc (char c) +{ + while ((jtag->txcntl & NIOS_JTAG_TRDY) != 0) + WATCHDOG_RESET (); + jtag->txcntl = NIOS_JTAG_TRDY | (unsigned char)c; +} + +void serial_puts (const char *s) +{ + while (*s != 0) + serial_putc (*s++); +} + +int serial_tstc (void) +{ + return (jtag->rxcntl & NIOS_JTAG_RRDY); +} + +int serial_getc (void) +{ + int c; + while (serial_tstc() == 0) + WATCHDOG_RESET (); + c = jtag->rxcntl & 0x0ff; + jtag->rxcntl = 0; + return (c); +} + +/*------------------------------------------------------------------ + * UART the serial port + *-----------------------------------------------------------------*/ +#else

static nios_uart_t *uart = (nios_uart_t *)CFG_NIOS_CONSOLE;

@@ -34,12 +76,12 @@ /* Everything's already setup for fixed-baud PTF * assignment */ -void serial_setbrg( void ){ return; } -int serial_init( void ) { return(0);} +void serial_setbrg (void){ return; } +int serial_init (void) { return (0);}

#else

-void serial_setbrg( void ) +void serial_setbrg (void) { DECLARE_GLOBAL_DATA_PTR; unsigned div; @@ -49,39 +91,44 @@ return; }

-int serial_init( void ) +int serial_init (void) { - serial_setbrg(); - return(0); + serial_setbrg (); + return (0); }

#endif /* CFG_NIOS_FIXEDBAUD */

-void serial_putc( char c ) +/*----------------------------------------------------------------------- + * UART CONSOLE + *---------------------------------------------------------------------*/ +void serial_putc (char c) { if (c == '\n') - serial_putc('\r'); - while( (uart->status & NIOS_UART_TRDY) == 0 ) + serial_putc ('\r'); + while ((uart->status & NIOS_UART_TRDY) == 0) WATCHDOG_RESET (); uart->txdata = (unsigned char)c; }

-void serial_puts( const char *s ) +void serial_puts (const char *s) { - while( *s != 0 ) { - serial_putc( *s++ ); + while (*s != 0) { + serial_putc (*s++); } }

-int serial_tstc( void ) +int serial_tstc (void) { - return( uart->status & NIOS_UART_RRDY); + return (uart->status & NIOS_UART_RRDY); }

-int serial_getc( void ) +int serial_getc (void) { - while( serial_tstc() == 0 ) + while (serial_tstc () == 0) WATCHDOG_RESET (); return( uart->rxdata & 0x00ff ); } + +#endif /* CONFIG_JTAG_CONSOLE */ diff -Naurb u-boot-2004APR25/cpu/nios/start.S nios-jtag-gdb/cpu/nios/start.S --- u-boot-2004APR25/cpu/nios/start.S 2003-10-08 19:26:14.000000000 -0400 +++ nios-jtag-gdb/cpu/nios/start.S 2004-04-25 15:44:11.000000000 -0400 @@ -93,6 +93,14 @@ subi %g6, 4 /* %g6 <- src addr */ ld %g7, [%g7] /* %g7 <- dst addr */

+ /* No need to move text sections if we're already located + * at the proper address. + */ + cmp %g7, %g6 + ifs cc_z + br reloc + nop /* delay slot */ + 1: cmp %g7, %g5 skps cc_nz br 2f @@ -114,6 +122,7 @@ pfx %xhi(reloc@h) movhi %g0, %xlo(reloc@h) jmp %g0 + nop /* delay slot */ reloc:

/* @@ -141,6 +150,48 @@ 4:

/* + * INIT VECTOR TABLE + */ + pfx %hi(CFG_VECT_BASE) + movi %g0, %lo(CFG_VECT_BASE) + pfx %xhi(CFG_VECT_BASE) + movhi %g0, %xlo(CFG_VECT_BASE) /* dst */ + mov %l0, %g0 + + pfx %hi(_vectors) + movi %g1, %lo(_vectors) + pfx %xhi(_vectors) + movhi %g1, %xlo(_vectors) /* src */ + bgen %g2, 6 /* cnt = 64 */ + + ldp %g3, [%l0, 3] /* bkpt vector */ + ldp %g4, [%l0, 4] /* single step vector */ + +5: ld %g7, [%g1] + addi %g1, 4 /* src++ */ + st [%g0], %g7 + addi %g0, 4 /* dst++ */ + + subi %g2, 1 /* cnt-- */ + ifrnz %g2 + br 5b + nop /* delay slot */ + +#if defined(CONFIG_ROM_STUBS) + /* Restore the breakpoint and single step exception + * vectors to their original values. + */ + stp [%l0,3], %g3 /* breakpoint */ + stp [%l0,4], %g4 /* single step */ +#endif + + /* For debug startup convenience ... software breakpoints + * set prior to this point may not succeed ;-) + */ + .global __start +__start: + + /* * Call board_init -- never returns */ pfx %hi(board_init@h) diff -Naurb u-boot-2004APR25/cpu/nios/traps.S nios-jtag-gdb/cpu/nios/traps.S --- u-boot-2004APR25/cpu/nios/traps.S 2003-10-08 19:26:14.000000000 -0400 +++ nios-jtag-gdb/cpu/nios/traps.S 2004-04-25 15:44:11.000000000 -0400 @@ -557,3 +557,26 @@ mov %fp, %sp

tret %o7 /* Done */ + +/************************************************************************* + * GDB stubs + ************************************************************************/ + .text + .global _brkpt_hw_int, _brkpt_sw_int + .align 4 + +_brkpt_hw_int: + movi %l1, 9 + pfx 3 + wrctl %l1 + pfx 4 + wrctl %l1 + +_brkpt_sw_int: + movi %l1, 9 + pfx 3 + wrctl %l1 + pfx 4 + wrctl %l1 + + tret %o7 diff -Naurb u-boot-2004APR25/doc/README.nios nios-jtag-gdb/doc/README.nios --- u-boot-2004APR25/doc/README.nios 2004-02-23 17:22:32.000000000 -0500 +++ nios-jtag-gdb/doc/README.nios 2004-04-25 17:36:18.000000000 -0400 @@ -55,6 +55,12 @@ a problem as little, if any, of the Altera source contains features that are not already available in U-Boot.

+1.3 Debugging via OCI +--------------------- +The Nios port supports debugging with gdb and/or nios-console +via the JTAG port. Stubs for debugging with gdb via the serial +port are not currently implemented. +

2. CONFIGURATION OPTIONS/SETTINGS ---------------------------------- @@ -79,7 +85,11 @@

CONFIG_NIOS -- defined for all Nios-32 boards.

-CFG_NIOS_CONSOLE -- the base address of the console UART. +CFG_NIOS_CONSOLE -- the base address of the console UART or the JTAG + stdio port. To enable a console via JTAG, define + CONFIG_CONSOLE_JTAG and set CGF_NIOS_CONSOLE to the base address + of the JTAG stdio port (normally OCI base + 0x00fa). Then + run nios-console with the -w option. (standard-32: nasys_uart_0 resp. na_uart1_base).

CFG_NIOS_FIXEDBAUD -- defined if the console UART PTF fixed_baud @@ -176,20 +186,109 @@ 3. Release CFG_NIOS_CPU_BUTTON_PIO, button number 0.

-5. BRAIN DAMAGE +5. DEBUGGING WITH GDB +--------------------- + +Debug sessions using gdb are currently supported only via JTAG. The +stubs for debugging via a serial port are not implemented. To enable +the gdb JTAG stubs, simply reference _brkpt_hw_int and _brkpt_sw_int +at vector table offsets 3 and 4, respectively. For an example, see +board/altera/dk1c20/vectors.S. + +5.1 Vector Table Initialization and ROM Stubs +--------------------------------------------- +If CONFIG_ROM_STUBS is defined, the debug breakpoint and single step +entries in the vector table are restored to their initial values +immediately _after_ initializing the vector table. Defining this macro +is useful when ROM-based stubs are implemented. + +NOTE: The default GERMS monitor does NOT implement gdb stubs, nor does +it initialize the vector table. Therefore, when debugging U-Boot, you +should NOT set a software breakpoint prior to vector table initialization. + +5.2 Starting a Debug Session +---------------------------- +If you're not familiar with gdb, you follow these step-by-step instructions. +These instructions are NOT the only way to start a debug session, but they +cover most of the individual functions to get you started. + + 1. Start the JTAG gdb server. Open a Nios shell window and start + the server. When the server is started you must provide the base + address of the OCI core. For example, when using the Cyclone + development kit (DK1C20): + + $ nios-gdb-server --ocibase=0x00920800 --tcpport=2342 + + 2. Start gdb. Open a Nios shell window, change to the top-level + U-Boot directory and start gdb, specifying the u-boot elf file: + + $ nios-elf-gdb u-boot + + 3. Update target settings. From the file menu, select + "Target Settings ..." and select the following, then click 'Ok': + + Target: Remote/TCP + Port : 2342 (same as in step 1) + Display download dialog: checked + All other check boxes: unchecked + + 4. Connect to the target. Select menu: 'Run->Connect to target'. + You should see a dialog box indicating the you successfully connected + to the target. + + 5. Download U-Boot. Select menu: 'Run->Download'. + + 6. Open a gdb console window and set the source directory paths. + Select menu: 'View->Console'. In the console window, enter the + following commands, then close the console window: + + (gdb) directory common + (gdb) directory cpu/nios + (gdb) directory lib_nios + (gdb) directory board/altera/dk1c20 + + Note that the last command is for the DK1C20 board only. If you + are using another board, specify that board's directory. + + 7. Open the file board.c (using the file menu in the lower + left hand corner). Scroll to the board_init() routine and set + a breakpoint. + + 8. Run U-Boot. Just click on the run icon, or select menu: + 'Run->Run'. U-Boot should start running, then break at your + breakpoint. + + 9. Have fun & start learning more about gdb. + + +5.3 For advanced Users +---------------------- +A few notes for those more familiar with gdb. + + -Serial port stubs are not implemented. Sorry, but it's just not + worth _my_ effort. The JTAG stubs work great and are ridiculously + simple to implement. + + -If you need to debug the early startup code (prior to the vector + table initialization), use the nios-console debugger. + + - Connect, download & run -- there are some problems here. Connect + download and run seperately to avoid trouble. + +6. 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.

-5.1 GERMS doesn't work with Hyperterminal +6.1 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.

-5.2 cygwin Incompatibility +6.2 cygwin Incompatibility --------------------------- The version of cygwin distributed with the nios GNUPro toolchain is out-of-date and incompatible with the latest cygwin distributions. @@ -202,7 +301,7 @@ The solution ... well, you can wait for Altera ... or build as set of tools for linux.

-5.3 No native gcc +6.3 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 @@ -215,7 +314,7 @@ toolchain can it found in the CDK4NIOS project hosted by Source Forge at http://cdk4nios.sourceforge.net.

-5.4 Can't build default U-Boot +6.4 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 @@ -232,15 +331,16 @@ -c -o $@ environment.c

With: -environment.o: environment.c ../tools/envcrc +environment.o: environment.c $(CC) $(AFLAGS) -Wa,--no-warn \ -DENV_CRC=0 \ -c -o $@ environment.c

-BTW, thats a 'zero' ... not the letter 'O'. +BTW, thats a 'zero' ... not the letter 'O'. And not that the +"../tools/envcrc" dependency is removed.

-6. HELP WANTED +7. HELP WANTED ---------------

There are plenty of areas where help is needed. Here's are some ideas diff -Naurb u-boot-2004APR25/examples/Makefile nios-jtag-gdb/examples/Makefile --- u-boot-2004APR25/examples/Makefile 2004-04-18 17:13:44.000000000 -0400 +++ nios-jtag-gdb/examples/Makefile 2004-04-25 15:44:11.000000000 -0400 @@ -38,7 +38,7 @@ endif

ifeq ($(ARCH),nios) -LOAD_ADDR = 0x01000000 -L $(gcclibdir)/m32 -T nios.lds +LOAD_ADDR = 0x00800000 -L $(gcclibdir)/m32 -T nios.lds endif

ifeq ($(ARCH),m68k) diff -Naurb u-boot-2004APR25/include/configs/DK1C20.h nios-jtag-gdb/include/configs/DK1C20.h --- u-boot-2004APR25/include/configs/DK1C20.h 2004-04-20 19:11:20.000000000 -0400 +++ nios-jtag-gdb/include/configs/DK1C20.h 2004-04-25 16:13:08.000000000 -0400 @@ -471,6 +471,7 @@ CFG_CMD_MII | \ CFG_CMD_PCI | \ CFG_CMD_PCMCIA | \ + CFG_CMD_REISER | \ CFG_CMD_SCSI | \ CFG_CMD_SPI | \ CFG_CMD_VFD | \ diff -Naurb u-boot-2004APR25/include/nios-io.h nios-jtag-gdb/include/nios-io.h --- u-boot-2004APR25/include/nios-io.h 2004-02-09 18:12:25.000000000 -0500 +++ nios-jtag-gdb/include/nios-io.h 2004-04-25 15:44:11.000000000 -0400 @@ -167,4 +167,17 @@ #define NIOS_ASMI_IEOP (1 << 9) /* rx eop int ena */ #define NIOS_ASMI_SSO (1 << 10) /* slave select enable */

+/*------------------------------------------------------------------------ + * JTAG UART + *----------------------------------------------------------------------*/ +typedef volatile struct nios_jtag_t { + unsigned short rxcntl; /* Rx data/cntl reg */ + unsigned short txcntl; /* Tx data/cntl reg */ + unsigned short errcntl; /* Err dta/cntl reg */ +}nios_jtag_t; + +/* status register */ +#define NIOS_JTAG_TRDY (1 << 8) /* tx ready bit */ +#define NIOS_JTAG_RRDY (1 << 8) /* rx ready bit */ + #endif /* __NIOSIO_H__ */ diff -Naurb u-boot-2004APR25/lib_nios/board.c nios-jtag-gdb/lib_nios/board.c --- u-boot-2004APR25/lib_nios/board.c 2004-02-23 18:54:52.000000000 -0500 +++ nios-jtag-gdb/lib_nios/board.c 2004-04-25 19:25:17.000000000 -0400 @@ -49,7 +49,6 @@

extern void malloc_bin_reloc (void); typedef int (init_fnc_t) (void); -extern unsigned _vectors[];

/* * Begin and End of memory area for malloc(), and current "brk" @@ -120,10 +119,6 @@ gd = (gd_t *)CFG_GBL_DATA_OFFSET; memset( gd, 0, CFG_GBL_DATA_SIZE );

- /* Copy exception vectors to the correct location. - */ - memcpy( (void *)CFG_VECT_BASE, _vectors, 256 ); - gd->bd = (bd_t *)(gd+1); /* At end of global data */ gd->baudrate = CONFIG_BAUDRATE; gd->cpu_clk = CONFIG_SYS_CLK_FREQ; diff -Naurb u-boot-2004APR25/nios_config.mk nios-jtag-gdb/nios_config.mk --- u-boot-2004APR25/nios_config.mk 2004-02-23 18:54:45.000000000 -0500 +++ nios-jtag-gdb/nios_config.mk 2004-04-25 19:24:02.000000000 -0400 @@ -22,4 +22,4 @@ # MA 02111-1307 USA #

-PLATFORM_CPPFLAGS += -m32 -DCONFIG_NIOS -D__NIOS__ -ffixed-g7 +PLATFORM_CPPFLAGS += -m32 -DCONFIG_NIOS -D__NIOS__ -ffixed-g7 -gstabs