APEX Bootloader

Summary
APEX is a bootloader for embedded systems. It was originally written to support the Sharp LH series of processors but has been ported to a number of additional ARM targets such as the Samsung S3C24xx series.


 * Easy to build. It depends only on shell utilities and GCC.
 * Easy to configure. There is a single configuration file and it uses the linux-2.6 Kconfig infrastructure.
 * Excellent dependency management. Uses Linux kernel Kbuild to optimally manage dependencies.
 * Modular. Commands and drivers may be included or excluded by configuration.
 * Supported targets: LH79520, LH79524, LH7A400, LH7A404, IXP42x (e.g. Linksys NSLU2), S3C24xx, and iMX31.
 * Support for RARP IP configuration and TFTP transfers to the target.
 * Filesystem drivers for FAT, EXT2, and JFFS2.
 * Partition driver for FIS as used by Redboot.
 * Small footprint. A limited feature version can be as small as 16KiB.
 * Support for booting APEX from non-memory-mapped storage, e.g. NAND flash, OneNAND, I2C

Source Code
all versions of APEX can be downloaded at: http://www.rad-tech-labs.com/apex/

2009-05-17 Version 1.6.9

 * Makefile (SUBLEVEL): v1.6.9
 * Closed debian bugs by fixing configuration files.
 * Applied http://svn.nslu2-linux.org/svnroot/kernel/trunk/patches/apex
 * src/drivers/driver.c (open_helper): New open helper used by the serial drivers and the memory driver. It's an always-success impementation for drivers that have nothing to do on open.
 * src/mach-orion5x/serial.c (orion5x_serial_init): Removed old console initialization as this is now done as a service.
 * src/mach-s3c2410/serial.c (s3c2410_serial_init): Removed old console initialization as this is now done as a service.
 * src/mach-lh7952x/serial.c (lh7952x_serial_init): Removed old console initialization as this is now done as a service.
 * src/mach-lh7a40x/serial.c (lh7a40x_serial_init): Removed old console initialization as this is now done as a service.
 * src/mach-mx3/serial-sc16c652.c (sc16c652_serial_init): Removed old console initialization as this is now done as a service.
 * src/mach-mx3/serial-mx31.c (mx31_serial_init): Removed old console initialization as this is now done as a service.
 * src/mach-ixp42x/serial.c (ixp42x_serial_init): Removed old console initialization as this is now done as a service.
 * src/apex/console.c (console_init): Console initialize as a service and configurable in the environment.
 * include/service.h (__service_4): Annotation that console is initialized in service 8.
 * include/driver.h (DRIVER_CONSOLE): Cleanup of macros.
 * src/mach-ixp42x/pci.c (pci_init): Commented out broken PCI interrupt type macros. Should be fixed.
 * src/apex/command.c (expand_variables): Revised expand_variables code to expand references within expanded references. This change permits us to define the kernel location, for example, as depending on the $serverip.

2009-01-23 Version 1.6.8

 * Makefile (SUBLEVEL): v1.6.8
 * src/mach-lh7a40x/initialize.c (target_init): Added code to the target initialization for Companion that initializes the modem.

2009-01-21 Version 1.6.7

 * Makefile (SUBLEVEL): v1.6.7 for push of new features.
 * src/drivers-lh/drv-mmc.c (mmc_report): Revised reporting to make it easier to troubleshoot cards.

2009-01-20 Version 1.6.6

 * include/mmc.h (mmc_card_acquired): Revised the card acquisition code so that we don't assume that the first byte of the CID register is non-zero. IMHO, our assumption was correct based on  the SD association's documentation, but we found that the Eye-FI card has a bogus looking card ID (CID) register and we have to be lenient to see it.
 * Makefile (SUBLEVEL): v1.6.6 for Companion fixes so it can use a 1.6.x version of APEX.
 * src/drivers/relocate-nand.c: Revised NAND relocator to work with the LPD7A404. Considering that the only other user of the code is a test implemented for the LH79524, this should be safe to rework.  The key difference is that the relocator  will address each page in turn instead of depending on an unreliable feature of NAND flash that automatically loads successive sectors.
 * src/arch-arm/Kconfig: Changed the Companion bootstrap to use the NAND relocator. This allows us to have a loader that is larger than 80KiB, the size of SRAM. Added a page size configuration option for relocation from NAND flash.
 * src/apex/cmd-version.c (cmd_version): Fixed display of environment variables s.t. the >64KiB length is properly shown in the version command output.
 * src/apex/cmd-image.c (cmd_image): Added an option to relocate	the ramdisk image s.t. the uBoot image format can be loaded with "image load" and then used to boot the system.

2009-01-05 Version 1.6.5

 * src/mach-orion5x/mv2120_config: Moving to the CodeSourcery compiler for thumb support.
 * src/arch-arm/lib/cp15-invalidate-dcache-va.c (invalidate_dcache_va): Conditionally compiling the invalidate-dcache-va function based on the presence of the macro and, therefore, the CP15 feature.
 * Makefile (SUBLEVEL): 1.6.5 for orion5x merge.
 * src/apex/cmd-flashusage.c (cmd_flashusage): New command to scan eraseblocks of a flash device for the presence of data.
 * src/mach-lh7952x/memory.h (RAM_BANK0_LENGTH): Fixed the declarations of the extents for the memory regions in the LH7952x. The macros were correct for the LH79524 but not the LH79520.  This is now fixed.
 * src/drivers/drv-ext2.c (ext2_identify): Revised EXT2 driver to took for extended partitions and to cope with 64 bit IO.
 * include/driver.h: Support for 64 bit IO sizes. This is only necessary for large devices like those accessible via ATA/SATA. It is optional and somewhat expensive.  Even the EXT2 driver will function without it, but it won't be able to see partitions past 2GiB.  This change trickled into lots of areas of APEX because of the change of types in the descriptor structure.  However, there should be no size or performance impact when the system is compiled without CONFIG_DRIVER_LONG_LONG_SIZE.
 * src/arch-arm/lib/muldi3.S: Inclusion of another kernel function for handling aeabi entry points. This was required by drv-ata when we compiled it with THUMB.
 * src/arch-arm/lib/cp15-wait.c: This and other cp15 functions so that cp15 operations can be invoked from THUMB code without THUMB2 support and without specialized code to detect the operation mode. These functions allow all code that lacks __asm's to be compiled with THUMB.
 * src/drivers/drv-fat.c (fat_open): Adding greater specificity to the region construction from the block_driver.
 * src/drivers/drv-ext2.c (ext2_open): Adding greater specificity to the region construction from the block_driver.
 * src/drivers/driver.c (parse_descriptor): Fix to disambiguate regions that could have path elements. The parser would not interpret driver:10k as having a start address of 10k when the driver could accept a path.  Now, parser will interpret driver:bin as having a path of 'bin', but driver:10k as having a starting offset as 10k.  The region can be unambiguously constructed using '@' and '/' appropriately.
 * src/mach-mx3/drv-i2c.c: New I2C driver for MX3x. Not complete, but working for writes to the I2C#1 controller.
 * src/mach-mx3/cmd-wm8955.c: New command for sending control messages to the WM8955L on the PSJL Karma.
 * src/drivers/driver.c (parse_descriptor): Fix for the parsing of FS descriptors such that the start address and length parameters may be set.(parse_descriptor): Added the '%' special character for combining one or more descriptors. This is used by the drivers that have a	basis driver defined in an environment variable, s.t. the driver can specify a starting address and/or length without knowing the exact form specified by the

2008-12-18 Version 1.6.4

 * Makefile (SUBLEVEL): Rolling revision for PSJL implementation. 1.6.4.
 * src/drivers/drv-nor-cfi.c (nor_probe_chip): Support for broken AMD/Spansion NOR flash that does not properly report top-boot vs. bottom-boot.
 * src/drivers/drv-nor-cfi.c: In order to support the Micronix (Spansion compatible) NOR flash in the HP MediaVault 2120, we needed to completely fill out the Spansion support. There is support for a single byte wide bus and a 16 bit internal logic as is the case on the MV2120.
 * src/drivers/drv-nor-cfi.c (ReadArray): Changed the ReadArray command for Spansion to 0xf0.
 * src/arch-arm/lib/cp15.c (cp15_ctrl): Enhanced the cp15 report on the control register to be more readable and to show more bits (ARMv6).
 * src/apex/cmd-image.c (cmd_image): Adding descriptor_open call to image load so that we can read from tftp.
 * src/drivers/drv-nor-cfi.c (nor_report): Cleanup of the nor flash driver report. Added start address and length that match the mem driver.
 * Makefile: Thumb support restored, required a little work to the src/arch-arm/lib code to guarantee interwork compatibility.
 * src/mach-mx3/exception_vectors.c: Implementation of exception	vectors on MX31, primarily in support of debugging THUMB.
 * src/arch-arm/lib/div64.S: Slight recoding of platform	implementations of basic functions to be interwork compatible.
 * src/net/tftp.c (tftp_receiver): Reporting on TFTP errors s.t. we properly detect file-not-found problems.

2008-11-13 Version 1.6.3

 * Makefile (SUBLEVEL): Version 1.6.3 for dm9000. The initial orion patches are in as well, but not yet supported.
 * src/drivers/drv-dm9000.c (dm9000_read): Implementation of dm9000_{read,write} to round out support for dm9000 as a complete Ethernet MAC/PHY driver.
 * src/lib/strtol.c: Adding strtol as a separate library function, in case it is needed. The memlimit command will use this function.
 * src/mach-mx3/rosencrantz.h (CCM_PDR0_V): Override for the PDR0 so that the CSI clock scalar is non-default.
 * src/mach-mx3/mx31.h (CCM_UPCTL_266_V): Fixed the UPCTL initialization values. This PLL is based on the CKIH, so it doesn't need to change when the CPU clock speed changes. (CCM_PDR0_V): Allowing this value to be overridden by the board 	specific header.
 * src/drivers/drv-mem.c (cmd_memlimit): Revised memlimit to permit a negative offset which is then subtracted from the total system memory.
 * debian/rules (binary-arch): Adding apex-image to the tools installed in the debian package.
 * src/apex/cmd-image-uboot.c: Documentation for UBOOT image format. (verify_uboot_image): Added support for multi-images. Now loading UBOOT images the same way that UBOOT does.
 * src/apex/region-checksum.c (region_checksum): Fixed the checksum to account for incoming CRC value as is necessary for UBOOT image CRC computation.
 * src/apex/cmd-image-uboot.c: Added uboot image support. No multi-images, but the rest works OK.
 * src/apex/region-checksum.c (region_checksum): Added neglected check for whether or not the caller wants the length added to the checksum
 * src/apex/cmd-image-apex.c (handle_apex_image): Factored out the APEX image code so we can implement UBOOT in separate file with optional compilation.
 * scripts/Makefile.build (modorder-target): Removed build of the module.order files.
 * src/apex/cmd-copy.c (cmd_copy): Fixed the return value so copy doesn't stop startup.
 * src/apex/cmd-image.c (handle_load_apex_image): Cleaned up the output and make the check and load functions look similar in output.
 * src/apex/region-checksum.c (region_checksum): Fixed checksumming so that we can sum over a defined range instead of being limited to summing the whole region.
 * src/apex/cmd-image.c (apex_image): Refactored cmd-image code to support a single driver for parsing through the header data.
 * src/apex/cmd-image.c (cmd_image): Fixed cascade testing of options.
 * src/lib/gmtime.c (gmtime_r): Fixed year calc (typo). (gmtime_r): Fixed month calc, off by one. convert_two_digits): Fixed representation of numbers; digits swapped.
 * src/lib/strimatch.c (strimatch): Fixed this function to properly match when the case is identical.
 * src/apex/cmd-help.c (compare_commands): Righted command sort order. (cmd_help): Eliminated a possible overflow of command listing array.
 * src/drivers/drv-mem.c (memory_write): Fixed un-aligned write code. The original test used were allowing invalid unaligned accesses.
 * src/mach-mx3/nor-cfi.h: Removed bogus override of the NOR flash memory command type.
 * src/mach-mx3/initialize.c (target_init): New initialization of the DM9000 memory region for MX31. The timing is much tighter and the OE and R_Wn timing has a better guarantee of accuracy.
 * src/drivers/drv-dm9000.c (cmd_eth): New 'r' and 'w' subcommands for inspecting registers of the DM9000. Renamed the 're' command to eeprom since that's what it does.
 * src/apex/services.c (init_services): More clear output from service startup in LL mode.
 * Makefile (SUBLEVEL): New version for changes to DM9000 code and for new KarmaV configuration.
 * src/drivers/drv-ext2.c: Added support for the inode_size field in the first revision of the second-extended filesystem's superblock.
 * debian/postinst: Fixed the postinst script to only run on the	NSLU2.

2007-10-16 Version 1.5.13

 * Makefile: The help make target now shows the configurations and the descriptions of them. (SUBLEVEL): 1.5.13.
 * src/drivers/relocate-nand.c: Fixed the basic NAND relocator. The code was previously broken as there was no configuration that used it.
 * src/drivers-lh/Kconfig: Added 565 option for LCD panel. Odd,	that we'd never implemented this before, but it is important to	note that the NXP LCD controller doesn't cope with 565 as well as 555.
 * src/mach-mx3/ipu.c: Inverted sense of LED outputs for testing	Rosencrantz.
 * src/mach-lh7a40x/clcdc-karma.c: Added adapter code for Karam LCD panel.
 * src/mach-lh7a40x/cmd-karmaaccel.c: Added accelerometer test code for Karma.
 * src/mach-lh7a40x/cmd-karmatouch.c: Added touch controller test code for Karma.
 * Removed a lot of cruft associated with older NAND flash implementations. NAND code is moved to the drivers directory.

2007-08-06 Version 1.5.11

 * Makefile (SUBLEVEL): Rolling to 1.5.11 just to make sure we got all of the timing parameter changes in a unique version.

2007-07-24 Version 1.5.10

 * Makefile (SUBLEVEL): rolling to 1.5.10 for fix to CPU timing on lh7a404.
 * src/mach-lh7a40x/initialize.c: Moved the clock speed setup to	the early initialization routine so that it is properly	configured.
 * usr/apex-env.cc (arg_parser): Added force option to the apex-env command. (main): Added partial command support so that 'apex-env rel' shows the release version.
 * src/arch-arm/entry/apex.lds.S: Removed Companion section from	the general build.

2007-06-25 Version 1.5.8

 * Makefile (SUBLEVEL): 1.5.8: Releasing for Debian package.
 * usr/apex-env.cc: Added release and region commands for probing the APEX environment.
 * src/apex/env.c: Added prefix option to the startup command. Removed crufty old ENV_STARTUP option that was mach specific.
 * src/arch-arm/entry/apex.lds.S: Renamed some of the sections to make the meanings clear. Preemtively fixed a vulnerability to	section reordering.  Fixed the setting of fSDRAMBoot so that it	works for INLINE init mode and for the older form.
 * src/mach-ixp42x/initialize.c (bootstrap_sdram_pre): Revamped the initialization code for ixp42x to use inline mode. Took the opportunity to elide a lot of cruft from the routines.  It isn't yet tested as written to flash as this requires setup of one of	the wigglers.  None of the typical uses of APEX on the ixp42x install APEX as the primary boot loader, so this can wait.
 * src/arch-arm/Kconfig: Configuration option to override the default SDRAM execution detection code. Most platforms can use the execution address to detect whether or not APEX is running in SDRAM.  Some, like the ixp42x map flash over SDRAM, so we have to use a custom piece of code to detect this circumstance.
 * src/arch-arm/Kconfig: Added AEABI configuration option so that we can link APEX with an AEABI toolchain. Really, the only difference is the inclusion of a couple of math functions.
 * src/arch-arm/lib/lib1funcs.S: Added config.h to build of lib1funcs so that the configuration dependencies are checked.

2007-06-02 Version 1.5.6

 * Makefile (SUBLEVEL): 1.5.6: Releasing version with fix section ordering.
 * src/arch-arm/entry/reset.c: Fixed a problem in the ordering of the reset sections that was illuminated by rwhitby's default compiler.

2007-06-01 Version 1.5.5

 * Makefile (SUBLEVEL): 1.5.5 for the SAVEATONCE option, very necessary for OneNAND stored environment.
 * src/lib/env.c: New option, CONFIG_ENV_SAVEATONCE implements a cached environment that is saved at one time to non-volatile storage instead of through incremental updates. This is necessary for some types of NAND flash where multiple writes to the same page are limited.
 * src/apex/*.c: Groomed error reporting for opening regions.
 * src/lib/env.c: Changed the environment region descriptor name to d_env so that it is easier to remember.

2007-05-30 Version 1.5.4

 * Makefile (SUBLEVEL): 1.5.4. Rolling revision for the sake of	the xscale fixes.
 * src/mach-mx3/cmd-sleep.c (cmd_sleep): Test code for MX31 sleep modes.
 * src/mach-mx3/cmd-reset.c (cmd_reset): Command verified.
 * src/arch-arm/entry/reset.c: Added a jump to reset_exit from reset in the event that we disable the MMU at startup. The ixp42x needs this because the xscale MMU flush code allocates data in the text section.
 * src/mach-ixp42x/initialize-sdram.c (cmd_initialize_sdram): Fixed the scan of 256Mib SDRAM chips. A small change to the algorithm and we seem to be able to detect 64MiB of memory just fine.
 * src/drivers/drv-mem.c (cmd_memscan): Error detection for region too small.
 * src/drivers/driver.c (parse_descriptor): Unparseable regions will now generate an error.
 * src/apex/cmd-version.c (cmd_version): Added a message about the currently set variation.

2007-05-24 Version 1.5.3

 * Makefile (SUBLEVEL): 1.5.3. Rolling rev for the sake of working IPU code, working sensor capture, and turing off of the illumination LEDs.
 * src/mach-mx3/ipu.c (cmd_ipu): Fixed the shutter width to increase frame rate.
 * src/mach-mx3/ipu.c (ipu_setup): Fixed the burst width to memory through the IPU DMAC.
 * src/drivers/drv-dm9000.c: Fixed failed probe code path. If the dm9000 isn't found, there will be no report.
 * src/mach-mx3/ipu.c: Adding view finder DMA task.
 * src/lib/env.c (env_check_magic): Fixed empty/broken environment region case.

2007-05-18 Version 1.5.2

 * Makefile (ARCH): Releasing 1.5.2.
 * src/arch-arm/Kconfig: Fixed companion boot by explicitly enabling the simple/NOR flash relocator as the primary relocator.
 * src/drivers/drv-nand.c (nand_sequential_input): Fixed the NAND driver to R/W on ST NAND parts.
 * src/mach-lh7952x/debug_ll.h: Fixed UART declarations.
 * src/mach-lh7952x/init-motoedge.c: Converted to inline platform initialization.
 * src/arch-arm/entry/relocate-simple.c: fixed relocate-simple because we changed the way we handle offsets.
 * Makefile (SUBLEVEL): Rolled to 1.5.2 so that we can keep track of this interim release.
 * src/apex/command.c (exec_monitor): Eliminated representation of empty commands in startup command list.
 * src/arch-arm/entry/apex.lds.S: Reorganized the sections and the section names to be more readable and consistent.
 * src/arch-arm/entry/reset.c: Restructured to allow for cleaner startup code. Legacy implementations are still OK, but the new plumbing permits seamless transitions between various initialization elements to handle constrained boot situations. Also removed an onerous constraint on register usage in the relocate_apex function.  The caller is now forced to assume that no registers are saved.
 * src/arch-arm/linux/atag.c (atag_header): Eliminated the core tag.

2007-05-10 Version 1.5.0

 * Releasing 1.5.0 with iMX31 and OneNAND.
 * src/drivers/relocate-onenand.c: Groomed the relocation for OneNAND to remove unneeded return address calculation.
 * src/drivers/drv-dm9000.c: Added code to help select the proper default interface when there could be two and only one is present.
 * src/mach-mx3/initialize.c: Groomed the startup code to remove much cruft.
 * src/apex/env.c: Fixed typo in the default environment startup command that was including the ramdisk startup even though there was none needed.
 * src/apex/command.c (call_command): Reorganized command invocation to report bogus command requests.
 * src/arch-arm/entry/apex.lds.S: Start of reorganization of the bootstrap so that we don't need to use function calls to handle early setup *and* we don't depend on macros.
 * src/drivers/relocate-onenand.c: Implementation of OneNAND APEX relocation for bootstrap.
 * src/apex/env.c: Improved the environment link so that it can exist even if there is no user-modifiable environment. This is to allow user-land to browse environment variables even if they cannot set them.
 * src/mach-lh7a40x/preinitialization-companion.c: Comment on preinitialization.
 * src/mach-mx3/ipu.c (cmd_ipu): Fixed the i2c code and added hooks to enable camera test patterns.
 * src/mach-mx3/initialize.c: Substantially enhanced the system setup. The IPU test code is now able to write to memory.
 * src/apex/cmd-version.c (cmd_version): Added target board description string.
 * src/mach-mx3/initialize.c: Extra check in the initialization routine so that we don't alter the timing registers if the CPU is already in the target mode. It looks like the CPU doesn't like the PLLs being changed once it has booted.  It may be the SDRAM that doesn't like the timing change.
 * src/arch-arm/entry/reset.c: Restored setting of the CPSR mode in the loader. The CPU boots in the undefined mode.  We move to supervisor mode, though this doesn't appear to be necessary for the kernel to boot.
 * src/mach-mx3/ipu.c (ipu_report): Improved clarity of IPU report to break out fields and to describe the formats in English.
 * include/asm/cp15-armv6.h: Fixed the cache control macros for the ARMV6.
 * src/mach-mx3/ipu.c: More IPU debug code. The report function has a clean rendering of the registers.
 * src/mach-mx3/mx31.h (CCM_PDR0_533_V): Switched to 533MHz CPU clock.
 * src/mach-mx3/uart.h (INITIALIZE_CONSOLE_UART): extended the FIFOS to 16 bytes.
 * src/mach-mx3/initialize.c: Added initialization of COSR even though we don't use it.
 * src/mach-mx3/Kconfig: New architecture number for Rosencrantz.
 * src/apex/services.c: Created this file to hold service init/release code.
 * src/apex/env.c: Added a "" to the startup command so that we can have an empty startup command.

Earlier Series

 * See full [[media:changlog.txt|Changelog]]