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| author | NIIBE Yutaka <gniibe@fsij.org> | 2016-05-31 11:49:01 +0900 |
|---|---|---|
| committer | NIIBE Yutaka <gniibe@fsij.org> | 2016-05-31 11:49:01 +0900 |
| commit | 3a4e1f2bd59a5185e638a2552c64344d78e0f54f (patch) | |
| tree | a25424f8b4264ab8c8485b5c086102061e885e4d /mcu/ABOUT-SYS | |
| parent | 421fd8019b31386c6e689753cf0a2ff35bd2af50 (diff) | |
Cleanup of sys and its macro
Diffstat (limited to 'mcu/ABOUT-SYS')
| -rw-r--r-- | mcu/ABOUT-SYS | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/mcu/ABOUT-SYS b/mcu/ABOUT-SYS index c5a7490..d285c88 100644 --- a/mcu/ABOUT-SYS +++ b/mcu/ABOUT-SYS @@ -4,6 +4,49 @@ Consideration about SYS and the first pages of flash ROM Now, I'm developing something like SYS for Kinetis L MCU, so, I write this document. +* Compatibility + + SYS 1.0: The first verson + SYS 2.0: Added clock_init, gpio_init + SYS 2.1: Added sys_board_id, sys_board_name + SYS 3.0: Don't setup NVIC priority by usb_lld_sys_init + + +* Macro definition by DEFS in Makefile + + - USE_SYS_CLOCK_GPIO_SETTING + + Define this macro to ask chopstx/entry.c (the runtime code before + MAIN function) to use function entries in SYS for clock_init and + gpio_init. + + If not defined, entry.c includes the code for clock_init and + gpio_init which might be different to a board, and use them (entries + in SYS will not be used). This works well with the ROM of SYS + 1.0. + + Note that SYS entries of clock_init and gpio_init were introduced + in SYS 2.0. So, enable this macro only if the ROM is SYS 2.0 or + later. + + - USE_SYS_BOARD_ID + + Define this macro in a driver to get "sys_board_id" in SYS, so + that the driver can support various boards at runtime by changing + the settings according to the board. + + A simple driver could only support a single board, by the compile + time (BOARD_ID in board-*.h) choice of of a settings. + + Note that SYS entries of sys_board_id and sys_board_name were + introduced in SYS 2.1. So, enable this macro only if the ROM is + SYS 2.1 or later. + + - USE_SYS3 + + By defining this, it will have same effect of defining both of + USE_SYS_CLOCK_GPIO_SETTING and USE_SYS_BOARD_ID internally. + About SYS on STM32F103 ====================== @@ -185,4 +228,12 @@ Three pages (3KiB) usage: +An Example of No-use of SYS +=========================== + +See example-fsm-55 for an example of no use of SYS. + +While chopstx/entry.c defines vectors in ROM and RAM, those are simply +discarded by example-fsm-55/hacker-emblem.ld. + -- |