X-Git-Url: https://git.kernelconcepts.de/?a=blobdiff_plain;f=README;h=f997a5d8605e91ff085da24eeaceac926cf9f194;hb=bfe8fe87bac5ad5b63aa64167c5fe719c3c300cd;hp=c90f6ee2d9dea89b8ca50b5563d6eaffc701342d;hpb=ced6466ed520749ea73651b45fabeb5a3efa9c8b;p=karo-tx-uboot.git diff --git a/README b/README index c90f6ee2d9..f997a5d860 100644 --- a/README +++ b/README @@ -1,5 +1,5 @@ # -# (C) Copyright 2000 - 2008 +# (C) Copyright 2000 - 2009 # Wolfgang Denk, DENX Software Engineering, wd@denx.de. # # See file CREDITS for list of people who contributed to this @@ -126,76 +126,104 @@ the string "u_boot" or on "U_BOOT". Example: Versioning: =========== -U-Boot uses a 3 level version number containing a version, a -sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", -sub-version "34", and patchlevel "4". +Starting with the release in October 2008, the names of the releases +were changed from numerical release numbers without deeper meaning +into a time stamp based numbering. Regular releases are identified by +names consisting of the calendar year and month of the release date. +Additional fields (if present) indicate release candidates or bug fix +releases in "stable" maintenance trees. -The patchlevel is used to indicate certain stages of development -between released versions, i. e. officially released versions of -U-Boot will always have a patchlevel of "0". +Examples: + U-Boot v2009.11 - Release November 2009 + U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree + U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release Directory Hierarchy: ==================== -- board Board dependent files -- common Misc architecture independent functions -- cpu CPU specific files - - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs - - arm720t Files specific to ARM 720 CPUs - - arm920t Files specific to ARM 920 CPUs - - at91rm9200 Files specific to Atmel AT91RM9200 CPU - - imx Files specific to Freescale MC9328 i.MX CPUs - - s3c24x0 Files specific to Samsung S3C24X0 CPUs - - arm925t Files specific to ARM 925 CPUs - - arm926ejs Files specific to ARM 926 CPUs - - arm1136 Files specific to ARM 1136 CPUs - - at32ap Files specific to Atmel AVR32 AP CPUs - - blackfin Files specific to Analog Devices Blackfin CPUs - - i386 Files specific to i386 CPUs - - ixp Files specific to Intel XScale IXP CPUs - - leon2 Files specific to Gaisler LEON2 SPARC CPU - - leon3 Files specific to Gaisler LEON3 SPARC CPU - - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs - - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs - - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs - - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs - - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs - - mips Files specific to MIPS CPUs - - mpc5xx Files specific to Freescale MPC5xx CPUs - - mpc5xxx Files specific to Freescale MPC5xxx CPUs - - mpc8xx Files specific to Freescale MPC8xx CPUs - - mpc8220 Files specific to Freescale MPC8220 CPUs - - mpc824x Files specific to Freescale MPC824x CPUs - - mpc8260 Files specific to Freescale MPC8260 CPUs - - mpc85xx Files specific to Freescale MPC85xx CPUs - - nios Files specific to Altera NIOS CPUs - - nios2 Files specific to Altera Nios-II CPUs - - ppc4xx Files specific to AMCC PowerPC 4xx CPUs - - pxa Files specific to Intel XScale PXA CPUs - - s3c44b0 Files specific to Samsung S3C44B0 CPUs - - sa1100 Files specific to Intel StrongARM SA1100 CPUs -- disk Code for disk drive partition handling -- doc Documentation (don't expect too much) -- drivers Commonly used device drivers -- dtt Digital Thermometer and Thermostat drivers -- examples Example code for standalone applications, etc. -- include Header Files -- lib_arm Files generic to ARM architecture -- lib_avr32 Files generic to AVR32 architecture -- lib_blackfin Files generic to Blackfin architecture -- lib_generic Files generic to all architectures -- lib_i386 Files generic to i386 architecture -- lib_m68k Files generic to m68k architecture -- lib_mips Files generic to MIPS architecture -- lib_nios Files generic to NIOS architecture -- lib_ppc Files generic to PowerPC architecture -- lib_sparc Files generic to SPARC architecture -- libfdt Library files to support flattened device trees -- net Networking code -- post Power On Self Test -- rtc Real Time Clock drivers -- tools Tools to build S-Record or U-Boot images, etc. +/arch Architecture specific files + /arm Files generic to ARM architecture + /cpu CPU specific files + /arm720t Files specific to ARM 720 CPUs + /arm920t Files specific to ARM 920 CPUs + /at91rm9200 Files specific to Atmel AT91RM9200 CPU + /imx Files specific to Freescale MC9328 i.MX CPUs + /s3c24x0 Files specific to Samsung S3C24X0 CPUs + /arm925t Files specific to ARM 925 CPUs + /arm926ejs Files specific to ARM 926 CPUs + /arm1136 Files specific to ARM 1136 CPUs + /ixp Files specific to Intel XScale IXP CPUs + /pxa Files specific to Intel XScale PXA CPUs + /s3c44b0 Files specific to Samsung S3C44B0 CPUs + /sa1100 Files specific to Intel StrongARM SA1100 CPUs + /lib Architecture specific library files + /avr32 Files generic to AVR32 architecture + /cpu CPU specific files + /lib Architecture specific library files + /blackfin Files generic to Analog Devices Blackfin architecture + /cpu CPU specific files + /lib Architecture specific library files + /i386 Files generic to i386 architecture + /cpu CPU specific files + /lib Architecture specific library files + /m68k Files generic to m68k architecture + /cpu CPU specific files + /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs + /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs + /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs + /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs + /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs + /lib Architecture specific library files + /microblaze Files generic to microblaze architecture + /cpu CPU specific files + /lib Architecture specific library files + /mips Files generic to MIPS architecture + /cpu CPU specific files + /lib Architecture specific library files + /nios2 Files generic to Altera NIOS2 architecture + /cpu CPU specific files + /lib Architecture specific library files + /powerpc Files generic to PowerPC architecture + /cpu CPU specific files + /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs + /mpc5xx Files specific to Freescale MPC5xx CPUs + /mpc5xxx Files specific to Freescale MPC5xxx CPUs + /mpc8xx Files specific to Freescale MPC8xx CPUs + /mpc8220 Files specific to Freescale MPC8220 CPUs + /mpc824x Files specific to Freescale MPC824x CPUs + /mpc8260 Files specific to Freescale MPC8260 CPUs + /mpc85xx Files specific to Freescale MPC85xx CPUs + /ppc4xx Files specific to AMCC PowerPC 4xx CPUs + /lib Architecture specific library files + /sh Files generic to SH architecture + /cpu CPU specific files + /sh2 Files specific to sh2 CPUs + /sh3 Files specific to sh3 CPUs + /sh4 Files specific to sh4 CPUs + /lib Architecture specific library files + /sparc Files generic to SPARC architecture + /cpu CPU specific files + /leon2 Files specific to Gaisler LEON2 SPARC CPU + /leon3 Files specific to Gaisler LEON3 SPARC CPU + /lib Architecture specific library files +/api Machine/arch independent API for external apps +/board Board dependent files +/common Misc architecture independent functions +/disk Code for disk drive partition handling +/doc Documentation (don't expect too much) +/drivers Commonly used device drivers +/examples Example code for standalone applications, etc. +/fs Filesystem code (cramfs, ext2, jffs2, etc.) +/include Header Files +/lib Files generic to all architectures + /libfdt Library files to support flattened device trees + /lzma Library files to support LZMA decompression + /lzo Library files to support LZO decompression +/net Networking code +/post Power On Self Test +/rtc Real Time Clock drivers +/tools Tools to build S-Record or U-Boot images, etc. Software Configuration: ======================= @@ -368,8 +396,10 @@ The following options need to be configured: * Adds the "fdt" command * The bootm command automatically updates the fdt - OF_CPU - The proper name of the cpus node. - OF_SOC - The proper name of the soc node. + OF_CPU - The proper name of the cpus node (only required for + MPC512X and MPC5xxx based boards). + OF_SOC - The proper name of the soc node (only required for + MPC512X and MPC5xxx based boards). OF_TBCLK - The timebase frequency. OF_STDOUT_PATH - The path to the console device @@ -386,6 +416,15 @@ The following options need to be configured: This define fills in the correct boot CPU in the boot param header, the default value is zero if undefined. + CONFIG_OF_IDE_FIXUP + + U-Boot can detect if an IDE device is present or not. + If not, and this new config option is activated, U-Boot + removes the ATA node from the DTS before booting Linux, + so the Linux IDE driver does not probe the device and + crash. This is needed for buggy hardware (uc101) where + no pull down resistor is connected to the signal IDE5V_DD7. + - vxWorks boot parameters: bootvx constructs a valid bootline using the following @@ -497,25 +536,6 @@ The following options need to be configured: must be defined, to setup the maximum idle timeout for the SMC. -- Interrupt driven serial port input: - CONFIG_SERIAL_SOFTWARE_FIFO - - PPC405GP only. - Use an interrupt handler for receiving data on the - serial port. It also enables using hardware handshake - (RTS/CTS) and UART's built-in FIFO. Set the number of - bytes the interrupt driven input buffer should have. - - Leave undefined to disable this feature, including - disable the buffer and hardware handshake. - -- Console UART Number: - CONFIG_UART1_CONSOLE - - AMCC PPC4xx only. - If defined internal UART1 (and not UART0) is used - as default U-Boot console. - - Boot Delay: CONFIG_BOOTDELAY - in seconds Delay before automatically booting the default image; set to -1 to disable autoboot. @@ -609,6 +629,7 @@ The following options need to be configured: CONFIG_CMD_DS4510_RST * ds4510 I2C rst command CONFIG_CMD_DTT * Digital Therm and Thermostat CONFIG_CMD_ECHO echo arguments + CONFIG_CMD_EDITENV edit env variable CONFIG_CMD_EEPROM * EEPROM read/write support CONFIG_CMD_ELF * bootelf, bootvx CONFIG_CMD_SAVEENV saveenv @@ -761,7 +782,7 @@ The following options need to be configured: CONFIG_LBA48 Set this to enable support for disks larger than 137GB - Also look at CONFIG_SYS_64BIT_LBA ,CONFIG_SYS_64BIT_VSPRINTF and CONFIG_SYS_64BIT_STRTOUL + Also look at CONFIG_SYS_64BIT_LBA. Whithout these , LBA48 support uses 32bit variables and will 'only' support disks up to 2.1TB. @@ -806,6 +827,16 @@ The following options need to be configured: - NETWORK Support (other): + CONFIG_DRIVER_AT91EMAC + Support for AT91RM9200 EMAC. + + CONFIG_RMII + Define this to use reduced MII inteface + + CONFIG_DRIVER_AT91EMAC_QUIET + If this defined, the driver is quiet. + The driver doen't show link status messages. + CONFIG_DRIVER_LAN91C96 Support for SMSC's LAN91C96 chips. @@ -830,20 +861,20 @@ The following options need to be configured: Define this to use i/o functions instead of macros (some hardware wont work with macros) - CONFIG_DRIVER_SMC911X + CONFIG_SMC911X Support for SMSC's LAN911x and LAN921x chips - CONFIG_DRIVER_SMC911X_BASE + CONFIG_SMC911X_BASE Define this to hold the physical address of the device (I/O space) - CONFIG_DRIVER_SMC911X_32_BIT + CONFIG_SMC911X_32_BIT Define this if data bus is 32 bits - CONFIG_DRIVER_SMC911X_16_BIT + CONFIG_SMC911X_16_BIT Define this if data bus is 16 bits. If your processor automatically converts one 32 bit word to two 16 bit - words you may also try CONFIG_DRIVER_SMC911X_32_BIT. + words you may also try CONFIG_SMC911X_32_BIT. - USB Support: At the moment only the UHCI host controller is @@ -1107,6 +1138,12 @@ The following options need to be configured: images, gzipped BMP images can be displayed via the splashscreen support or the bmp command. +- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 + + If this option is set, 8-bit RLE compressed BMP images + can be displayed via the splashscreen support or the + bmp command. + - Compression support: CONFIG_BZIP2 @@ -1361,10 +1398,18 @@ The following options need to be configured: to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie the CPU's i2c node address). - Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) - sets the CPU up as a master node and so its address should - therefore be cleared to 0 (See, eg, MPC823e User's Manual - p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0. + Now, the u-boot i2c code for the mpc8xx + (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node + and so its address should therefore be cleared to 0 (See, + eg, MPC823e User's Manual p.16-473). So, set + CONFIG_SYS_I2C_SLAVE to 0. + + CONFIG_SYS_I2C_INIT_MPC5XXX + + When a board is reset during an i2c bus transfer + chips might think that the current transfer is still + in progress. Reset the slave devices by sending start + commands until the slave device responds. That's all that's required for CONFIG_HARD_I2C. @@ -1435,6 +1480,16 @@ The following options need to be configured: #define I2C_DELAY udelay(2) + CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA + + If your arch supports the generic GPIO framework (asm/gpio.h), + then you may alternatively define the two GPIOs that are to be + used as SCL / SDA. Any of the previous I2C_xxx macros will + have GPIO-based defaults assigned to them as appropriate. + + You should define these to the GPIO value as given directly to + the generic GPIO functions. + CONFIG_SYS_I2C_INIT_BOARD When a board is reset during an i2c bus transfer @@ -1446,6 +1501,17 @@ The following options need to be configured: custom i2c_init_board() routine in boards/xxx/board.c is run early in the boot sequence. + CONFIG_SYS_I2C_BOARD_LATE_INIT + + An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is + defined a custom i2c_board_late_init() routine in + boards/xxx/board.c is run AFTER the operations in i2c_init() + is completed. This callpoint can be used to unreset i2c bus + using CPU i2c controller register accesses for CPUs whose i2c + controller provide such a method. It is called at the end of + i2c_init() to allow i2c_init operations to setup the i2c bus + controller on the CPU (e.g. setting bus speed & slave address). + CONFIG_I2CFAST (PPC405GP|PPC405EP only) This option enables configuration of bi_iic_fast[] flags @@ -1715,7 +1781,7 @@ The following options need to be configured: ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, HERMES, IP860, RPXlite, LWMON, LANTEC, - PCU_E, FLAGADM, TQM8260 + FLAGADM, TQM8260 - Error Recovery: CONFIG_PANIC_HANG @@ -1870,25 +1936,6 @@ The following options need to be configured: example, some LED's) on your board. At the moment, the following checkpoints are implemented: -- Automatic software updates via TFTP server - CONFIG_UPDATE_TFTP - CONFIG_UPDATE_TFTP_CNT_MAX - CONFIG_UPDATE_TFTP_MSEC_MAX - - These options enable and control the auto-update feature; - for a more detailed description refer to doc/README.update. - -- MTD Support (mtdparts command, UBI support) - CONFIG_MTD_DEVICE - - Adds the MTD device infrastructure from the Linux kernel. - Needed for mtdparts command support. - - CONFIG_MTD_PARTITIONS - - Adds the MTD partitioning infrastructure from the Linux - kernel. Needed for UBI support. - Legacy uImage format: Arg Where When @@ -1920,9 +1967,9 @@ Legacy uImage format: 13 common/image.c Start multifile image verification 14 common/image.c No initial ramdisk, no multifile, continue. - 15 lib_/bootm.c All preparation done, transferring control to OS + 15 arch//lib/bootm.c All preparation done, transferring control to OS - -30 lib_ppc/board.c Fatal error, hang the system + -30 arch/powerpc/lib/board.c Fatal error, hang the system -31 post/post.c POST test failed, detected by post_output_backlog() -32 post/post.c POST test failed, detected by post_run_single() @@ -2042,6 +2089,25 @@ FIT uImage format: -150 common/cmd_nand.c Incorrect FIT image format 151 common/cmd_nand.c FIT image format OK +- Automatic software updates via TFTP server + CONFIG_UPDATE_TFTP + CONFIG_UPDATE_TFTP_CNT_MAX + CONFIG_UPDATE_TFTP_MSEC_MAX + + These options enable and control the auto-update feature; + for a more detailed description refer to doc/README.update. + +- MTD Support (mtdparts command, UBI support) + CONFIG_MTD_DEVICE + + Adds the MTD device infrastructure from the Linux kernel. + Needed for mtdparts command support. + + CONFIG_MTD_PARTITIONS + + Adds the MTD partitioning infrastructure from the Linux + kernel. Needed for UBI support. + Modem Support: -------------- @@ -2283,6 +2349,14 @@ Configuration Settings: on high Ethernet traffic. Defaults to 4 if not defined. +- CONFIG_ENV_MAX_ENTRIES + + Maximum number of entries in the hash table that is used + internally to store the environment settings. The default + setting is supposed to be generous and should work in most + cases. This setting can be used to tune behaviour; see + lib/hashtable.c for details. + The following definitions that deal with the placement and management of environment data (variable area); in general, we support the following configurations: @@ -2424,6 +2498,19 @@ to save the current settings. - CONFIG_SYS_EEPROM_SIZE: The size in bytes of the EEPROM device. + - CONFIG_ENV_EEPROM_IS_ON_I2C + define this, if you have I2C and SPI activated, and your + EEPROM, which holds the environment, is on the I2C bus. + + - CONFIG_I2C_ENV_EEPROM_BUS + if you have an Environment on an EEPROM reached over + I2C muxes, you can define here, how to reach this + EEPROM. For example: + + #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0" + + EEPROM which holds the environment, is reached over + a pca9547 i2c mux with address 0x70, channel 3. - CONFIG_ENV_IS_IN_DATAFLASH: @@ -2478,7 +2565,7 @@ to save the current settings. Please note that the environment is read-only until the monitor has been relocated to RAM and a RAM copy of the environment has been -created; also, when using EEPROM you will have to use getenv_r() +created; also, when using EEPROM you will have to use getenv_f() until then to read environment variables. The environment is protected by a CRC32 checksum. Before the monitor @@ -2501,13 +2588,6 @@ use the "saveenv" command to store a valid environment. - CONFIG_SYS_FAULT_MII_ADDR: MII address of the PHY to check for the Ethernet link state. -- CONFIG_SYS_64BIT_VSPRINTF: - Makes vsprintf (and all *printf functions) support printing - of 64bit values by using the L quantifier - -- CONFIG_SYS_64BIT_STRTOUL: - Adds simple_strtoull that returns a 64bit value - - CONFIG_NS16550_MIN_FUNCTIONS: Define this if you desire to only have use of the NS16550_init and NS16550_putc functions for the serial driver located at @@ -2658,7 +2738,7 @@ Low Level (hardware related) configuration options: CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) - Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. + Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. - CONFIG_PCI_DISABLE_PCIE: Disable PCI-Express on systems where it is supported but not @@ -2966,7 +3046,9 @@ environment. As long as you don't save the environment you are working with an in-memory copy. In case the Flash area containing the environment is erased by accident, a default environment is provided. -Some configuration options can be set using Environment Variables: +Some configuration options can be set using Environment Variables. + +List of environment variables (most likely not complete): baudrate - see CONFIG_BAUDRATE @@ -3001,14 +3083,6 @@ Some configuration options can be set using Environment Variables: configuration from the BOOTP server, but not try to load any image using TFTP - autoscript - if set to "yes" commands like "loadb", "loady", - "bootp", "tftpb", "rarpboot" and "nfs" will attempt - to automatically run script images (by internally - calling "source"). - - autoscript_uname - if script image is in a format (FIT) this - variable is used to get script subimage unit name. - autostart - if set to "yes", an image loaded using the "bootp", "rarpboot", "tftpboot" or "diskboot" commands will be automatically started (by internally calling @@ -3077,16 +3151,16 @@ Some configuration options can be set using Environment Variables: interface is currently active. For example you can do the following - => setenv ethact FEC ETHERNET - => ping 192.168.0.1 # traffic sent on FEC ETHERNET - => setenv ethact SCC ETHERNET - => ping 10.0.0.1 # traffic sent on SCC ETHERNET + => setenv ethact FEC + => ping 192.168.0.1 # traffic sent on FEC + => setenv ethact SCC + => ping 10.0.0.1 # traffic sent on SCC ethrotate - When set to "no" U-Boot does not go through all available network interfaces. It just stays at the currently selected interface. - netretry - When set to "no" each network operation will + netretry - When set to "no" each network operation will either succeed or fail without retrying. When set to "once" the network operation will fail when all the available network interfaces @@ -3102,7 +3176,18 @@ Some configuration options can be set using Environment Variables: tftpdstport - If this is set, the value is used for TFTP's UDP destination port instead of the Well Know Port 69. - vlan - When set to a value < 4095 the traffic over + tftpblocksize - Block size to use for TFTP transfers; if not set, + we use the TFTP server's default block size + + tftptimeout - Retransmission timeout for TFTP packets (in milli- + seconds, minimum value is 1000 = 1 second). Defines + when a packet is considered to be lost so it has to + be retransmitted. The default is 5000 = 5 seconds. + Lowering this value may make downloads succeed + faster in networks with high packet loss rates or + with unreliable TFTP servers. + + vlan - When set to a value < 4095 the traffic over Ethernet is encapsulated/received over 802.1q VLAN tagged frames. @@ -3218,6 +3303,11 @@ o If both the SROM and the environment contain a MAC address, and the o If neither SROM nor the environment contain a MAC address, an error is raised. +If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses +will be programmed into hardware as part of the initialization process. This +may be skipped by setting the appropriate 'ethmacskip' environment variable. +The naming convention is as follows: +"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. Image Formats: ============== @@ -3247,8 +3337,8 @@ details; basically, the header defines the following image properties: Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, INTEGRITY). * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, - IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; - Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC). + IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; + Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC). * Compression Type (uncompressed, gzip, bzip2) * Load Address * Entry Point @@ -3299,7 +3389,7 @@ configure the Linux device drivers for use with your target hardware (no, we don't intend to provide a full virtual machine interface to Linux :-). -But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). +But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). Just make sure your machine specific header file (for instance include/asm-ppc/tqm8xx.h) includes the same definition of the Board @@ -3397,7 +3487,7 @@ So a typical call to build a U-Boot image would read: -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ - > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ + > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ > examples/uImage.TQM850L Image Name: 2.4.4 kernel for TQM850L Created: Wed Jul 19 02:34:59 2000 @@ -3421,10 +3511,10 @@ speed for memory and install an UNCOMPRESSED image instead: this needs more space in Flash, but boots much faster since it does not need to be uncompressed: - -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz + -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ - > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ + > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ > examples/uImage.TQM850L-uncompressed Image Name: 2.4.4 kernel for TQM850L Created: Wed Jul 19 02:34:59 2000 @@ -3901,7 +3991,9 @@ For PowerPC, the following registers have specific use: R30: GOT pointer R31: frame pointer - (U-Boot also uses R14 as internal GOT pointer.) + (U-Boot also uses R12 as internal GOT pointer. r12 + is a volatile register so r12 needs to be reset when + going back and forth between asm and C) ==> U-Boot will use R2 to hold a pointer to the global data @@ -3931,6 +4023,14 @@ On ARM, the following registers are used: ==> U-Boot will use R8 to hold a pointer to the global data +On Nios II, the ABI is documented here: + http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf + + ==> U-Boot will use gp to hold a pointer to the global data + + Note: on Nios II, we give "-G0" option to gcc and don't use gp + to access small data sections, so gp is free. + NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, or current versions of GCC may "optimize" the code too much.