From 7dc9903be8206d24136606ec5a72d1dd7335bb13 Mon Sep 17 00:00:00 2001 From: Eao3piq4e Date: Tue, 2 Aug 2022 09:19:40 +0800 Subject: [PATCH] Update bbox_elf_dump_base.cpp --- .../cbb/bbox/bbox_elf_dump_base.cpp | 21 ++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/src/gausskernel/cbb/bbox/bbox_elf_dump_base.cpp b/src/gausskernel/cbb/bbox/bbox_elf_dump_base.cpp index 6e2a265f3..c4f965609 100644 --- a/src/gausskernel/cbb/bbox/bbox_elf_dump_base.cpp +++ b/src/gausskernel/cbb/bbox/bbox_elf_dump_base.cpp @@ -44,11 +44,22 @@ static int g_iPosBlackList = 0; /* array store for black list */ static BBOX_BLACKLIST_STRU g_stBlackList[BBOX_BLACK_LIST_COUNT_MAX]; -/* - * Determines whether the byte order of the local machine is large or small - * return : ELFDATA2LSB - large - * : ELFDATA2MSB - small - */ + /* +function name: BBOX_DetermineMsb +description: The function should judge the mode that PC uses to store data is Big-endian/Little-endian. +arguments: void +return value: An integer that indicates the mode is Big-endian/Little-endian, + if it is ELFDATA2LSB, the mode is Little-endian, + if it is ELFDATA2MSB, the mode is Big-endian. +noteļ¼šThe way that this function judge the mode that PC uses to store data is through a union variable unProbe, + at first we give its first member variable sShortInt a value BBOX_MSB_LSB_INT of type short, then its second + member variable cSplit[sizeof(short)] equaling to cSplit[2] would have the equal value of the first. Finally we + just need to compare BBOX_LITTER_BITS and BBOX_HIGH_BITS, namely the low byte and high byte of + BBOX_MSB_LSB_INT, with unProbe.cSplit[0] and unProbe.cSplit[1], if they are correspondingly equal, the mode is + Little-endian, else is the Big-endian. +date: 2022/8/2 +contact tel: 18720816902 + */ int BBOX_DetermineMsb(void) { union INT_PROBE {