Hello Simon, Tom,
I am just stumbeld on an am437x basd board over the problem to pass the bootmode from SPL to U-Boot. On am437x the bootmode info get overwritten from SPL stack, and I need this info in U-Boot.
Hack would be to move SPL stack to another address, but we loose than 0xa000 size for stack ... I do not want to go this way..
I thought gd info is passed from SPL to U-Boot, but this is not the case!
Looking into
... 75 bic r0, r0, #7 /* 8-byte alignment for ABI compliance */ 76 mov sp, r0 77 bl board_init_f_alloc_reserve 78 mov sp, r0 79 /* set up gd here, outside any C code */ 80 mov r9, r0 81 bl board_init_f_init_reserve
and common/init/board_init.c:
99 void board_init_f_init_reserve(ulong base) 100 { 101 struct global_data *gd_ptr; 102 103 /* 104 * clear GD entirely and set it up. 105 * Use gd_ptr, as gd may not be properly set yet. 106 */ 107 108 gd_ptr = (struct global_data *)base; 109 /* zero the area */ 110 memset(gd_ptr, '\0', sizeof(*gd)); 111 /* set GD unless architecture did it already */ 112 #if !defined(CONFIG_ARM) 113 arch_setup_gd(gd_ptr); 114 #endif
gd is always initialized with zeros, no chance for passing infos from SPL to U-Boot...
I really thought, that gd_t was intentionally designed for passing data between different U-Boot states, but looking into gd_t definiton in include/asm-generic/global_data.h it is a big ifdef mess and not useable as an "API" between TPL/SPL and U-Boot ...
I thought also, that SPL detects for example ramsize and than passes this info to U-Boot ...
But Ok, I found "common/init/handoff.c" which seems now the way to go, but:
./common/board_f.c
281 static int setup_spl_handoff(void) 282 { 283 #if CONFIG_IS_ENABLED(HANDOFF) 284 gd->spl_handoff = bloblist_find(BLOBLISTT_SPL_HANDOFF, 285 sizeof(struct spl_handoff)); 286 debug("Found SPL hand-off info %p\n", gd->spl_handoff); 287 #endif 288 289 return 0; 290 }
There is gd->spl_handoff used ... how could this work at least on arm, if gd is set to zeros on init ?
Do I miss something obvious?
bye, Heiko