add some feature to U-Boot

This commit is contained in:
Chiharu Shirasaka 2021-06-28 05:42:25 +09:00 committed by GitHub
parent 7c2200e371
commit 308d2c3ed0
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1 changed files with 41 additions and 2 deletions

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@ -3,10 +3,42 @@
.global _start
_start:
ldr r0, =0x67800000
//preload U-Boot from sd
ldr r4, .L3
adr r1, [.LC0]
adr r0, [.LC1]
mov r3, r4
blx r3
add r5, r4, #0xc
mov r3, r0
ldr r0, .L3+4
mov r1, #1
mov r2, r0
blx r5
cpsid if
//copy U-Boot to head of RAM
ldr r3, =0x37500000
ldr r1, =0x37540000
.L2:
mov r2, r3
sub r3, r3, #0x7500000
ldr r0, [r2], #4
cmp r2, r1
str r0, [r3]
mov r3, r2
bne .L2
ldr r0, =0x60000000
//MUB Interrupt Disable
ldr r2,=0x40220064
ldr r3,[r2]
ldr r1,=0x0000ffff
and r3,r3,r1
str r3,[r2]
mrc p15, 0, r8, c14, c2, 1
bic r8, r8, #1
mcr p15, 0, r8, c14, c2, 1
@ -54,5 +86,12 @@ _start:
bic r6, r6, #1 @ disable MMU
mcr p15, 0, r6, c1, c0, 0 // write ctrl regs
mov pc, r0
bx r0
.L3:
.word 0x60006400
.word 0x37500000
.LC0:
.ascii "r\000"
.LC1:
.ascii "SD0:\\u-boot.bin\000"