ACPICA: Application: Enhance ACPI_USAGE_xxx/ACPI_OPTION with acpi_os_printf() to improve portability

This patch enhances ACPI_USAGE_xxx/ACPI_OPTION macros to use portable
acpi_os_printf() so that usage functions for applications no longer rely on
the printf() API.

To use acpi_os_printf() exported by osunixxf.c as a replacement of
printf(), applications need to initialize acpi_gbl_output_file to stdout
and initialize acpi_gbl_db_output_flags to ACPI_DB_CONSOLE_OUTPUT. The
latter is automatically done by ACPI_INIT_GLOBAL(), applications need to
link utglobal.o to utilize this mechanism. For GCC, assigning stdout to
acpi_gbl_output_file using ACPI_INIT_GLOBAL() is not possible as stdout is
not a constant in GCC environment. As an alternative solution, stdout
assignment has been put into acpi_os_initialize(). Thus
acpi_os_initialize() need to be invoked very early by the applications to
initialize the default output of acpi_os_printf() to keep behavior
consistency.

acpidump has already invoked acpi_os_initialize() in this way. Lv Zheng.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2 files changed