uclinux-2008R1-RC8(bf561)到VDSP5的移植(49)：kernel_thread_helper的问题

 

在arch/blackfin/kernel/process.c中有这样一个函数：

/*

 * This gets run with P1 containing the

 * function to call, and R1 containing

 * the "args". Note P0 is clobbered on the way here.

 */

void kernel_thread_helper(void);

__asm__(".section .text/n"

     ".align 4/n"

     "_kernel_thread_helper:/n/t"

     "/tsp += -12;/n/t"

     "/tr0 = r1;/n/t" "/tcall (p1);/n/t" "/tcall _do_exit;/n" ".previous");

它将引发一个错误：

[Error ea5004] "c:/temp/acc06a8ef03000/acc06a8ef03001.s":67 Syntax Error in :

.align 2;

syntax error is at or near text '.align'.

Attempting error recovery by ignoring text until the ';'

 

 Previous errors prevent assembly

 

Assembler totals: 1 error(s) and 0 warning(s)

cc3089: fatal error: Assembler failed

怎么看都找不到.align 2这行语句。

逐行屏蔽这些汇编语句后发现，问题出在 ".previous"这行上，查了下.previous：

The .PREVIOUS directive instructs the assembler to set the current section in memory to the section described immediately before the current one. The .PREVIOUS directive operates on a stack.

Syntax:

   .PREVIOUS;

The following examples provide valid and invalid cases of the use of the consecutive . PREVIOUS directives.

嘿嘿，原来少了个分号，影响到下面的C程序的生成了。

改为 ".previous;"后搞定。