API for external applications.

This is an API for external (standalone) applications running on top of
U-Boot, and is meant to be more extensible and robust than the existing
jumptable mechanism. It is similar to UNIX syscall approach. See api/README
for more details.

Included is the demo application using this new framework (api_examples).

Please note this is still an experimental feature, and is turned off by
default.

Signed-off-by: Rafal Jaworowski <[email protected]>

Makefile

@@ -243,6 +243,9 @@ LIBS += $(shell if [ -d post/board/$(BOARDDIR) ]; then echo \
 	"post/board/$(BOARDDIR)/libpost$(BOARD).a"; fi)
 LIBS += common/libcommon.a
 LIBS += libfdt/libfdt.a
+ifeq ($(CONFIG_API),y)
+LIBS += api/libapi.a
+endif
 
 LIBS := $(addprefix $(obj),$(LIBS))
 .PHONY : $(LIBS)
@@ -255,6 +258,10 @@ PLATFORM_LIBS += -L $(shell dirname `$(CC) $(CFLAGS) -print-libgcc-file-name`) -
 SUBDIRS	= tools \
 	  examples
 
+ifeq ($(CONFIG_API),y)
+SUBDIRS += api_examples
+endif
+
 .PHONY : $(SUBDIRS)
 
 ifeq ($(CONFIG_NAND_U_BOOT),y)
@@ -2749,6 +2756,7 @@ clean:
 	rm -f $(obj)board/bf537-stamp/u-boot.lds $(obj)board/bf561-ezkit/u-boot.lds
 	rm -f $(obj)include/bmp_logo.h
 	rm -f $(obj)nand_spl/u-boot-spl $(obj)nand_spl/u-boot-spl.map
+	rm -f $(obj)api_examples/demo
 
 clobber:	clean
 	find $(OBJTREE) -type f \( -name .depend \
@@ -2762,6 +2770,8 @@ clobber:	clean
 	rm -f $(obj)tools/inca-swap-bytes $(obj)cpu/mpc824x/bedbug_603e.c
 	rm -f $(obj)include/asm/proc $(obj)include/asm/arch $(obj)include/asm
 	[ ! -d $(OBJTREE)/nand_spl ] || find $(obj)nand_spl -lname "*" -print | xargs rm -f
+	find $(obj)api_examples -lname "*" -print | xargs rm -f
+	rm -f $(obj)api_examples/demo
 
 ifeq ($(OBJTREE),$(SRCTREE))
 mrproper \

api/Makefile

@@ -0,0 +1,40 @@
+#
+# (C) Copyright 2007 Semihalf
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundatio; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+include $(TOPDIR)/config.mk
+
+LIB	= $(obj)libapi.a
+
+COBJS	= api.o api_net.o api_storage.o api_platform-$(ARCH).o
+
+SRCS	:= $(COBJS:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS))
+
+all:	$(LIB)
+
+$(LIB):	$(obj).depend $(OBJS)
+	$(AR) $(ARFLAGS) $@ $(OBJS)
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend

api/README

@@ -0,0 +1,55 @@
+U-Boot machine/arch independent API for external apps
+=====================================================
+
+1.  Main assumptions
+
+  - there is a single entry point (syscall) to the API
+
+  - per current design the syscall is a C-callable function in the U-Boot
+    text, which might evolve into a real syscall using machine exception trap
+    once this initial version proves functional
+
+  - the consumer app is responsible for producing appropriate context (call
+    number and arguments)
+
+  - upon entry, the syscall dispatches the call to other (existing) U-Boot
+    functional areas like networking or storage operations
+
+  - consumer application will recognize the API is available by searching
+    a specified (assumed by convention) range of address space for the
+    signature
+
+  - the U-Boot integral part of the API is meant to be thin and non-intrusive,
+    leaving as much processing as possible on the consumer application side,
+    for example it doesn't keep states, but relies on hints from the app and
+    so on 
+
+  - optional (CONFIG_API)
+
+
+2. Calls
+
+  - console related (getc, putc, tstc etc.)
+  - system (reset, platform info)
+  - time (delay, current)
+  - env vars (enumerate all, get, set)
+  - devices (enumerate all, open, close, read, write); currently two classes
+    of devices are recognized and supported: network and storage (ide, scsi,
+    usb etc.)
+
+
+3. Structure overview
+
+  - core API, integral part of U-Boot, mandatory
+    - implements the single entry point (mimics UNIX syscall)
+
+  - glue
+    - entry point at the consumer side, allows to make syscall, mandatory
+      part
+
+    - helper conveniency wrappers so that consumer app does not have to use
+      the syscall directly, but in a more friendly manner (a la libc calls),
+      optional part
+
+  - consumer application
+    - calls directly, or leverages the provided glue mid-layer