From 07f6a61d034d715e0340b6ffcffffa6dc6034662 Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Tue, 8 Jun 2021 08:13:54 +0200 Subject: bsps/sparc: Remove support to load data section Remove the support to load the data section and rely on the boot loader. The code is an artifact from the old erc32 days, when we would boot and execute from ROM and the .data had to be copied over to RAM. With leon1/2/3, this is not used anymore as a boot loader is made from the RAM image using a custom tool (mkprom). In SMP configurations, this support was also broken since LEON3_Boot_Cpu (in the data section due to the -1 initialization value) was used quite early in the start sequence. If the data copy is really necessary, then an application can still add this step as a very early system initialization step, since boot_card() and the system initialization loop does not use initialized read-write data (only read-only and BSS data). However, the SMP startup would still not work in this case. A boot loader is a better place to load the sections. --- bsps/sparc/shared/start/start.S | 36 ++++-------------------------------- 1 file changed, 4 insertions(+), 32 deletions(-) diff --git a/bsps/sparc/shared/start/start.S b/bsps/sparc/shared/start/start.S index f7caacf0e4..369ef72a94 100644 --- a/bsps/sparc/shared/start/start.S +++ b/bsps/sparc/shared/start/start.S @@ -331,47 +331,19 @@ SYM(hard_reset): mov %sp, %fp ! Set frame pointer nop - /* - * Copy the initialized data to RAM - * - * FROM: _data_load_start - * TO: _data_start - * LENGTH: (__bss_start - _data_start) bytes - */ - - sethi %hi(_data_load_start),%g1 ! g1 = start of initialized data in ROM - or %g1,%lo(_data_load_start),%g1 - - sethi %hi(_data_start),%g3 ! g3 = start of initialized data in RAM - or %g3,%lo(_data_start),%g3 + /* clear the bss */ - sethi %hi(__bss_start), %g2 ! g2 = end of initialized data in RAM + sethi %hi(__bss_start), %g2 ! g2 = start of bss or %g2,%lo(__bss_start),%g2 - cmp %g1, %g3 - be 1f - nop - -copy_data: - ldd [%g1], %g4 - std %g4 , [%g3] ! copy this double word - add %g3, 8, %g3 ! bump the destination pointer - add %g1, 8, %g1 ! bump the source pointer - cmp %g3, %g2 ! Is the pointer past the end of dest? - bl copy_data - nop - - /* clear the bss */ -1: - sethi %hi(_end),%g3 or %g3,%lo(_end),%g3 ! g3 = end of bss mov %g0,%g1 ! so std has two zeros -zerobss: +.Lzerobss: std %g0,[%g2] add %g2,8,%g2 cmp %g2,%g3 - bleu,a zerobss + bleu,a .Lzerobss nop mov %g0, %o0 ! command line -- cgit v1.2.3