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Simplify init assembly

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This commit is contained in:
Vladimir 'phcoder' Serbinenko 2013-04-12 16:50:58 +02:00
parent 04e80baa32
commit b624c94856
2 changed files with 20 additions and 44 deletions
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37
grub-core/kern/arm/uboot/startup.S
View file

@ -65,20 +65,28 @@ FUNCTION(codestart)
ldr sp, =entry_state
push {r4-r12,lr} @ store U-Boot context (sp in r12)
@ Put kernel parameters aside until we can store them (further down)
mov r4, r1 @ machine type
mov r5, r2 @ boot data
ldr r12, =EXT_C(uboot_machine_type)
str r1, [r12]
ldr r12, =EXT_C(uboot_boot_data)
str r2, [r12]
@ Modules have been stored as a blob in BSS,
@ they need to be manually relocated to _end or
@ (__bss_start + grub_total_module_size), whichever greater.
bl uboot_get_real_bss_start @ r0 = src
ldr r0, =EXT_C(__bss_start) @ src
add r0, r0, #(GRUB_KERNEL_MACHINE_MOD_ALIGN - 1)
mvn r1, #(GRUB_KERNEL_MACHINE_MOD_ALIGN - 1)
and r0, r0, r1
ldr r1, =EXT_C(_end) @ dst = End of BSS
ldr r2, grub_total_module_size @ blob size
add r3, r0, r2 @ blob end
cmp r1, r3 @ _end < blob end?
movlt r1, r3 @ dst = blob end + blob size
ldr r12, =EXT_C(grub_modbase)
str r1, [r12]
1: ldr r3, [r0], #4 @ r3 = *src++
str r3, [r1], #4 @ *dst++ = r3
subs r2, #4 @ remaining -= 4
@ -91,34 +99,15 @@ FUNCTION(codestart)
@ Since we _are_ the C run-time, we need to manually zero the BSS
@ region before continuing
bl uboot_get_real_bss_start @ zero from here
ldr r0, =EXT_C(__bss_start) @ zero from here
ldr r1, =EXT_C(_end) @ to here
mov r2, #0
1: str r2, [r0], #4
cmp r0, r1
bne 1b
@ Global variables now accessible - store kernel parameters in memory
ldr r12, =EXT_C(uboot_machine_type)
str r4, [r12]
ldr r12, =EXT_C(uboot_boot_data)
str r5, [r12]
b EXT_C(grub_main)
/*
* __bss_start does not actually point to the start of the runtime
* BSS, but rather to the next byte following the preceding data.
*/
FUNCTION (uboot_get_real_bss_start)
ldr r0, =EXT_C(__bss_start) @ src
tst r0, #(GRUB_KERNEL_MACHINE_MOD_ALIGN - 1)
beq 1f
mvn r1, #(GRUB_KERNEL_MACHINE_MOD_ALIGN - 1)
and r0, r0, r1
add r0, r0, #(GRUB_KERNEL_MACHINE_MOD_ALIGN)
1: bx lr
/*
* uboot_syscall():
* This function is effectively a veneer, so it cannot

25
grub-core/kern/uboot/init.c
View file

@ -35,10 +35,10 @@ extern char _end[];
extern grub_size_t grub_total_module_size;
extern int (*uboot_syscall_ptr) (int, int *, ...);
grub_addr_t grub_modbase;
grub_uint32_t uboot_machine_type;
grub_addr_t uboot_boot_data;
/* Set to anything other than zero so it lands in .data and not .bss. */
grub_addr_t grub_modbase = 0x55aa55aa;
grub_uint32_t uboot_machine_type = 0x55aa55aa;
grub_addr_t uboot_boot_data = 0x55aa55aa;
static unsigned long timer_start;
@ -69,7 +69,6 @@ uboot_timer_ms (void)
void
grub_machine_init (void)
{
grub_addr_t end, real_bss_start;
int ver;
/* First of all - establish connection with U-Boot */
@ -85,26 +84,14 @@ grub_machine_init (void)
uboot_puts ("invalid U-Boot API version\n");
}
/*
* Modules were relocated to _end, or __bss_start + grub_total_module_size,
* whichever greater. (And __bss_start may not point to actual BSS start...)
*/
real_bss_start = uboot_get_real_bss_start ();
end = real_bss_start + grub_total_module_size;
if (end < (grub_addr_t) _end)
end = (grub_addr_t) _end;
grub_modbase = end;
/* Initialize the console so that GRUB can display messages. */
grub_console_init_early ();
/* Enumerate memory and initialize the memory management system. */
grub_uboot_mm_init ();
grub_dprintf ("init", "__bss_start: 0x%08x, real_bss_start: 0x%08x\n",
(grub_addr_t) __bss_start, real_bss_start);
grub_dprintf ("init", "end: 0x%08x, _end: 0x%08x\n",
(grub_addr_t) end, (grub_addr_t) _end);
grub_dprintf ("init", "__bss_start: %p\n", __bss_start);
grub_dprintf ("init", "_end: %p\n", _end);
grub_dprintf ("init", "grub_modbase: %p\n", (void *) grub_modbase);
grub_dprintf ("init", "grub_modules_get_end(): %p\n",
(void *) grub_modules_get_end ());