The SD boot loader was not satisfactory because 1) the SD slot is on an optional board and, hence, cannot be part of a fundamental solution. And 2) it is too big.
The only storage on borard is the Winbond W25 SPI-bsed FLASH. This commit adds support for a bootload to 1) read code in HEX format from a serial port and write it to the W25 FLASH, or 2) read code in binary form from the W25 FLASH into SRAM and execute the loaded program.
boards/z80/ez80/z20x/configs: Added w25boot configuration
boards/z80/ez80/z20x/src: Add bootloader logic, w25_main.c. Add logic to manage shared SRAM memory map so that the loaded program does not clobber the bootloader memory. Add logic to recover the bootloader memory into the heap after the loaded program as started.
boards/z80/ez80/z20x/scripts: Rework scripts and configuration to support a bootloader and program build. The boolloader cannot use all of SRAM; the program must not clobber the SRAM region used by the bootloader.
board/z80/ez80/*/scripts/Make.defs: Fix optimization definition use in assembly flags. It was using the compiler optimization settings instead of the assembler optimization settings. Hence, enabling optimization would could cause assembler command line errors.
arch/z80/src/ez80/Toolchain.defs: Back out some work arounds. Now compiler optimization flags can again set set without assembler command line errors.
boards/z80/ez80/z20x/README.txt: Trivial update to size/optimization discussion.
The eZ80F92 interrupt controller is very different from the eZ80F91. The eZ80F91 has:
1. Four byte interrupt vectors
2. The vector base address register is 16-bit so the vector table can lie in RAM
Whereas the eZ80F92 has:
1. Two byte interrupt vectors
2. An 8-bit vector base address
This means that the vectors must lie in the first 16-bits of FLASH and there must be a "trampoline" to get to interrupt handlers outside of the first 64-Kb of FLASH.
arch/z80/src/ez80/Toolchain.defs: Correct some CFLAGS when optimization suppressed.
arch/z80/src/ez80/Kconfig arch/z80/src/ez80/ez80_emac.c: Remove configuration option for selecting EMAC RAM address. This is duplicated and possibly conflicting. The correct address for the RAM is provided in the linker command file. The RAM should be configured once and using this single definitions.
arch/z80/src/ez80/ez80_startup.asm and arch/z80/src/ez80/ez80f9*_init.asm. Move RAM and FLAH intialization out of MCU-specific logic to common start-up logic. We cannot call any functions until SRAM is initialized and the stack is properly initialized because the return address is stored on the stack. Use internal SRAM for the IDLE stack to avoid the chicken'n'egg problem.
boards/z80/ez80/z20x/configs/sdboot/sdboot.zdsproj: Discuss build environments.
arch/z80/src/ez80/Toolchain.defs: Update some CFLAGS to match CFLAGS from ZDS-II IDE. Apparently, we must say that the CPU is an eZ80F91 event when compiler for eZ80F92.
boards/z80/ez80/z20x: Update linker scripts.
* tools/zds/zds_Config.mk: Move boards/z80/ez80/scripts/eZ80_Config.mk to tools/zds/zds_Config.mk where it can be shared by other ZDS-II platforms.
* boards/z16/z16f: Duplicate changes for new ZDS-II support from ez80
* boards/z80/z8: Duplicate changes for new ZDS-II support from ez80
* arch/z16/src/z16f/Toolchain.defs: Create required Toolchain.defs file for Z16f
arch/z80/arc/ez80/Toolchain.sh: Move more common toolchain definitions from Make.defs.
boards/z80/ez80/scripts/eZ80_Config.mk: Move common defines that override tools/Config.mk to this new file.
This does not solve the ez80 build problem yet but does assure that when the solution is in place, it will automatically apply to all present and future ez80 configurations.
