Jump to uncertain (run-time determined) address in assembly language

Sometimes I want program to jump to uncertain (run-time determined) address like function pointer does in C language. For example, a function table. If the chip supports "jsr" with register indirect addressing, like H8, it will be as simple as
    jsr   @er0
But on the core I am using called "Flex RISC", 8bit, performs as peripheral device in an ARM based SoC, thers is only one "jsr" instruction which using immediate addressing. Branch instructions (brXX) and jmp instruction do the same.
At last I found there is another instruction changes PC pointer, "rts". It pop PC point from stack. So here is the way out:
    ...
; variable SomeAddr keeps SomeFunc's sddress
    ld     a1, SomeAddr
    ld     a2, SomeAddr + 1
    jsr    CallByAddr
    ...

SomeFunc:
    ...
    rts          ; this "rts" will exactly returns from the "jsr".

CallByAddr:
    psh    a2
    psh    a1
    rts          ; this "rts" will pop a2a1 to PC that makes SomeFunc called.

Vim的2html脚本

用Vim直接转HTML，很方便。

:runtime! syntax/2html.vim

Windows版要把“/”反过来写成“\”。

用Cscope帮助Vim浏览代码

1. 建立cscope.out的脚本makecs.sh，makecs.sh 。



#/bin/bash

TEMPLATE=cscope.XXXXXX

if [ -n "$1" ]; then
	cd "$1";

	TEMP_FILE=$(mktemp "$TEMPLATE")
	find -regex '.*\.\([ch]\|[ch][px][px]\|pgc\)' | grep -v '.svn' > "$TEMP_FILE"
	cscope -b -i "$TEMP_FILE"

	rm "$TEMP_FILE"
else
	echo "makecs <dir>"
	exit 1
fi



2. Cscope插件

autoload_cscope，放在./vim/plugin/或者/usr/share/vim/vim70/plugin/。我下的是0.3，78行的“find c”改成了“find s”，在175、176行加入了*.pgc。

3. 用法

C-] = 查定义

C-\, s = 查引用

C-\, c = 查调用