Hi Marek,
Sorry for rate reply.
On 2021/05/25 16:35, Marek Vasut wrote:
On 5/12/21 4:09 PM, Kunihiko Hayashi wrote:
When CONFIG_ENV_IS_NOWHERE is enabled, env_nowhere_init() sets ENV_INVALID
to gd->env_valid, and sets default_environment before relocation to
gd->env_addr. After that, env_init() switches gd->env_valid to ENV_VALID
by the previous fix.
If gd->env_valid is ENV_INVALID, env_get_char() returns relocated
default_environment, however, env_get_char() returns gd->env_addr before
relocation since gd->env_valid is ENV_VALID, and access to gd->env_addr
will cause a fault.
This leaves gd->env_valid as ENV_INVALID for "nowhere" location.
So do I understand this correctly that _after_ relocation, env_init() is
called and env_init() does not update gd->env_addr to the relocated one?
In my understandings, env_init() belongs to init_sequence_f[]
and env_init() is called before relocation.
I would expect that after relocation, if all you have is env_nowhere
driver, the env_nowhere_init() is called again from the first for() loop
of env_init() [1], which would set gd->env_valid to ENV_INVALID [1], and
that for() loop would exit with ret = -ENOENT [2], so then the last part
of env_init() would check for ret == -ENOENT and update gd->env_addr to
relocated default_environment [3].
324 int env_init(void)
325 {
326 struct env_driver *drv;
327 int ret = -ENOENT;
328 int prio;
329
330 for (prio = 0; (drv = env_driver_lookup(ENVOP_INIT, prio)); prio++) {
/* Part [1] */
331 if (!drv->init || !(ret = drv->init()))
332 env_set_inited(drv->location);
333 if (ret == -ENOENT)
334 env_set_inited(drv->location);
335
336 debug("%s: Environment %s init done (ret=%d)\n", __func__,
337 drv->name, ret);
338
/* Part [2] */
339 if (gd->env_valid == ENV_INVALID)
340 ret = -ENOENT;
341 }
342
343 if (!prio)
344 return -ENODEV;
345
/* Part [3] */
346 if (ret == -ENOENT) {
/* This should be relocated default_environment address */
347 gd->env_addr = (ulong)&default_environment[0];
348 gd->env_valid = ENV_VALID;
349
350 return 0;
351 }
352
353 return ret;
354 }
Or am I missing something obvious ?
These are called before relocation, and update gd->env_addr to non-relocated
default_environment by [3].
After that, gd->env_addr is relocated in initr_reloc_global_data()
if CONFIG_SYS_RELOC_GD_ENV_ADDR is defined.
| #ifdef CONFIG_SYS_RELOC_GD_ENV_ADDR
| /*
| * Relocate the early env_addr pointer unless we know it is not inside
| * the binary. Some systems need this and for the rest, it doesn't hurt.
| */
| gd->env_addr += gd->reloc_off;
| #endif
However, I misunderstood my situation.
gd->reloc_off doesn't have the proper value because CONFIG_SYS_TEXT_BASE
is zero due to CONFIG_POSITION_INDENENDENT=y.
gd->reloc_off is calculated with CONFIG_SYS_TEXT_BASE in setup_reloc().
| gd->reloc_off = gd->relocaddr - CONFIG_SYS_TEXT_BASE;
gd->env_addr is added with gd->reloc_off (== gd->relocaddr - 0),
as a result, gd->env_addr has wrong address.
In this case, I think the proper solution is to undefine
CONFIG_SYS_RELOC_GD_ENV_ADDR.
My patch isn't necessary no longer and your patch also works with
"nowhere".
Thank you,
---
Best Regards
Kunihiko Hayashi
