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firmware: Use lla to access all global symbols

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When OpenSBI is compiled as fPIE mode, the assembler will translate "la"
to GOT reference pattern. It will cause to cost an additional load
instruction when obtaining the symbol address. However, if the symbol
locates within the positive or negative 2GB region, we can use "lla"
instead of "la" to avoid unneeded GOT references. This patch assumes that
the OpenSBI image excluding the payload does not exceed 2GB. Based on
this assumption, all "la" instructions are replaced by "lla" to avoid
performance degradation when compiling as fPIE mode.

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
This commit is contained in:
Vincent Chen
2021-03-17 09:16:37 +08:00
committed by Anup Patel
parent ff5bd949d5
commit 22d8ee9758
5 changed files with 64 additions and 64 deletions
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18
firmware/payloads/test_head.S
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@@ -28,20 +28,20 @@
.globl _start
_start:
/* Pick one hart to run the main boot sequence */
la a3, _hart_lottery
lla a3, _hart_lottery
li a2, 1
amoadd.w a3, a2, (a3)
bnez a3, _start_hang
/* Save a0 and a1 */
la a3, _boot_a0
lla a3, _boot_a0
REG_S a0, 0(a3)
la a3, _boot_a1
lla a3, _boot_a1
REG_S a1, 0(a3)
/* Zero-out BSS */
la a4, _bss_start
la a5, _bss_end
lla a4, _bss_start
lla a5, _bss_end
_bss_zero:
REG_S zero, (a4)
add a4, a4, __SIZEOF_POINTER__
@@ -53,18 +53,18 @@ _start_warm:
csrw CSR_SIP, zero
/* Setup exception vectors */
la a3, _start_hang
lla a3, _start_hang
csrw CSR_STVEC, a3
/* Setup stack */
la a3, _payload_end
lla a3, _payload_end
li a4, 0x2000
add sp, a3, a4
/* Jump to C main */
la a3, _boot_a0
lla a3, _boot_a0
REG_L a0, 0(a3)
la a3, _boot_a1
lla a3, _boot_a1
REG_L a1, 0(a3)
call test_main