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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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39
grub-core/kern/arm/uboot/startup.S
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@ -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