请教一下vmlinux.lds.S链接脚本
arm体系结构如下的DISCARD这个段是干嘛用的？
"/DISCARD/"是个段名？为什么两边要加上"/"呢？
多谢
SECTIONS
{
/*
* XXX: The linker does not define how output sections are
* assigned to input sections when there are multiple statements
* matching the same input section name.There is no documented
* order of matching.
*
* unwind exit sections must be discarded before the rest of the
* unwind sections get included.
*/
/DISCARD/ : {
*(.ARM.exidx.exit.text)
*(.ARM.extab.exit.text)
ARM_CPU_DISCARD(*(.ARM.exidx.cpuexit.text))
ARM_CPU_DISCARD(*(.ARM.extab.cpuexit.text))
ARM_EXIT_DISCARD(EXIT_TEXT)
ARM_EXIT_DISCARD(EXIT_DATA)
EXIT_CALL
#ifndef CONFIG_HOTPLUG
*(.ARM.exidx.devexit.text)
*(.ARM.extab.devexit.text)
#endif
#ifndef CONFIG_MMU
*(.fixup)
*(__ex_table)
#endif
#ifndef CONFIG_SMP_ON_UP
*(.alt.smp.init)
#endif
*(.discard)
*(.discard.*)
}
ld.pdf中有写
The special output section name ‘/DISCARD/’ may be used to discard input sections. Any
input sections which are assigned to an output section named ‘/DISCARD/’ are not included
in the output file. 回复 2# arm-linux-gcc
多谢
那我直接不把这些section链接进来不就行了嘛，为嘛要特别说明一下？
回复 3# super皮波
从
unwind exit sections must be discarded before the rest of the
* unwind sections get included.
这句话看来，应该是想法unwind整体信息的exit部分剔除出去。但又不想一个一个的加进来，所以采用了减法。
假设 unwind total = A + B+ C + D
则 include A + include B + include C = include total - exclude C
这样还能防止以后unwind信息出现扩展时必须更改链接脚本的。
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