#
-# (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
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:
=======================
* 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
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
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
CONFIG_CMD_KGDB * kgdb
CONFIG_CMD_LOADB loadb
CONFIG_CMD_LOADS loads
+ CONFIG_CMD_MD5SUM print md5 message digest
+ (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
loop, loopw, mtest
CONFIG_CMD_MISC Misc functions like sleep etc
(requires CONFIG_CMD_I2C)
CONFIG_CMD_SETGETDCR Support for DCR Register access
(4xx only)
+ CONFIG_CMD_SHA1 print sha1 memory digest
+ (requires CONFIG_CMD_MEMORY)
CONFIG_CMD_SOURCE "source" command Support
CONFIG_CMD_SPI * SPI serial bus support
CONFIG_CMD_USB * USB support
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.
- 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.
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
MPC5200 USB requires additional defines:
CONFIG_USB_CLOCK
for 528 MHz Clock: 0x0001bbbb
+ CONFIG_PSC3_USB
+ for USB on PSC3
CONFIG_USB_CONFIG
for differential drivers: 0x00001000
for single ended drivers: 0x00005000
+ for differential drivers on PSC3: 0x00000100
+ for single ended drivers on PSC3: 0x00004100
CONFIG_SYS_USB_EVENT_POLL
May be defined to allow interrupt polling
instead of using asynchronous interrupts
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
Defines a default value for the IP address of a TFTP
server to contact when using the "tftboot" command.
+ CONFIG_KEEP_SERVERADDR
+
+ Keeps the server's MAC address, in the env 'serveraddr'
+ for passing to bootargs (like Linux's netconsole option)
+
- Multicast TFTP Mode:
CONFIG_MCAST_TFTP
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.
#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
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
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
13 common/image.c Start multifile image verification
14 common/image.c No initial ramdisk, no multifile, continue.
- 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
+ 15 arch/<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()
-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:
--------------
- 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:
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
- 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
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
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
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
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
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.
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:
==============
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
(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
-> 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
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
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
average for all boards 752 bytes for the whole U-Boot image,
624 text + 127 data).
-On Blackfin, the normal C ABI (except for P5) is followed as documented here:
+On Blackfin, the normal C ABI (except for P3) is followed as documented here:
http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
- ==> U-Boot will use P5 to hold a pointer to the global data
+ ==> U-Boot will use P3 to hold a pointer to the global data
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.
projects / karo-tx-uboot.git / blobdiff