uclinux-2008R1-RC8(bf561)到VDSP5的移植(49)：kernel_thread_helper的問題

在arch/blackfin/kernel/process.c中有這樣一個函數：

/*
* 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");

它將引發一個錯誤：

[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

怎麼看都找不到.align 2這行語句。

逐行屏蔽這些匯編語句後發現，問題出在".previous"這行上，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，原來少了個分號，影響到下面的C程序的生成了。

改為".previous;"後搞定。