tests/tcg: make aarch64 boot.S handle different starting modes

Currently the boot.S code assumes everything starts at EL1. This will
break things like the memory test which will barf on unaligned memory
access when run at a higher level.

Adapt the boot code to do some basic verification of the starting mode
and the minimal configuration to move to the lower exception levels.
With this we can run the memory test with:

  -M virt,secure=on
  -M virt,secure=on,virtualization=on
  -M virt,virtualisation=on

If a test needs to be at a particular EL it can use the semihosting
command line to indicate the level we should execute in.

Cc: Julian Armistead <julian.armistead@linaro.org>
Cc: Jim MacArthur <jim.macarthur@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-ID: <20250603110204.838117-4-alex.bennee@linaro.org>
This commit is contained in:
Alex Bennée
2025-06-07 15:15:30 +01:00
parent cfd7ebd9b0
commit 4f5c81844c
2 changed files with 169 additions and 6 deletions
+2 -1
View File
@@ -68,7 +68,8 @@ run-plugin-semiconsole-with-%: semiconsole
# vtimer test needs EL2
QEMU_EL2_MACHINE=-machine virt,virtualization=on,gic-version=2 -cpu cortex-a57 -smp 4
run-vtimer: QEMU_OPTS=$(QEMU_EL2_MACHINE) $(QEMU_BASE_ARGS) -kernel
QEMU_EL2_BASE_ARGS=-semihosting-config enable=on,target=native,chardev=output,arg="2"
run-vtimer: QEMU_OPTS=$(QEMU_EL2_MACHINE) $(QEMU_EL2_BASE_ARGS) -kernel
# Simple Record/Replay Test
.PHONY: memory-record
+167 -5
View File
@@ -16,6 +16,7 @@
#define semihosting_call hlt 0xf000
#define SYS_WRITEC 0x03 /* character to debug channel */
#define SYS_WRITE0 0x04 /* string to debug channel */
#define SYS_GET_CMDLINE 0x15 /* get command line */
#define SYS_EXIT 0x18
.align 12
@@ -70,21 +71,172 @@ lower_a32_sync:
lower_a32_irq:
lower_a32_fiq:
lower_a32_serror:
adr x1, .unexp_excp
exit_msg:
mov x0, SYS_WRITE0
adr x1, .error
semihosting_call
mov x0, 1 /* EXIT_FAILURE */
bl _exit
/* never returns */
.section .rodata
.error:
.string "Terminated by exception.\n"
.unexp_excp:
.string "Unexpected exception.\n"
.high_el_msg:
.string "Started in lower EL than requested.\n"
.unexp_el0:
.string "Started in invalid EL.\n"
.align 8
.get_cmd:
.quad cmdline
.quad 128
.text
.align 4
.global __start
__start:
/*
* Initialise the stack for whatever EL we are in before
* anything else, we need it to be able to _exit cleanly.
* It's smaller than the stack we pass to the C code but we
* don't need much.
*/
adrp x0, system_stack_end
add x0, x0, :lo12:system_stack_end
mov sp, x0
/*
* The test can set the semihosting command line to the target
* EL needed for the test. However if no semihosting args are set we will
* end up with -kernel/-append data (see semihosting_arg_fallback).
* Keep the normalised target in w11.
*/
mov x0, SYS_GET_CMDLINE
adr x1, .get_cmd
semihosting_call
adrp x10, cmdline
add x10, x10, :lo12:cmdline
ldrb w11, [x10]
/* sanity check, normalise char to EL, clamp to 1 if outside range */
subs w11, w11, #'0'
b.lt el_default
cmp w11, #3
b.gt el_default
b 1f
el_high:
adr x1, .high_el_msg
b exit_msg
el_default:
mov w11, #1
1:
/* Determine current Exception Level */
mrs x0, CurrentEL
lsr x0, x0, #2 /* CurrentEL[3:2] contains the current EL */
/* Are we already in a lower EL than we want? */
cmp w11, w0
bgt el_high
/* Branch based on current EL */
cmp x0, #3
b.eq setup_el3
cmp x0, #2
b.eq setup_el2
cmp x0, #1
b.eq at_testel /* Already at EL1, skip transition */
/* Should not be at EL0 - error out */
adr x1, .unexp_el0
b exit_msg
setup_el3:
/* Ensure we trap if we get anything wrong */
adr x0, vector_table
msr vbar_el3, x0
/* Does the test want to be at EL3? */
cmp w11, #3
beq at_testel
/* Configure EL3 to for lower states (EL2 or EL1) */
mrs x0, scr_el3
orr x0, x0, #(1 << 10) /* RW = 1: EL2/EL1 execution state is AArch64 */
orr x0, x0, #(1 << 0) /* NS = 1: Non-secure state */
msr scr_el3, x0
/*
* We need to check if EL2 is actually enabled via ID_AA64PFR0_EL1,
* otherwise we should just jump straight to EL1.
*/
mrs x0, id_aa64pfr0_el1
ubfx x0, x0, #8, #4 /* Extract EL2 field (bits 11:8) */
cbz x0, el2_not_present /* If field is 0 no EL2 */
/* Prepare SPSR for exception return to EL2 */
mov x0, #0x3c9 /* DAIF bits and EL2h mode (9) */
msr spsr_el3, x0
/* Set EL2 entry point */
adr x0, setup_el2
msr elr_el3, x0
/* Return to EL2 */
eret
el2_not_present:
/* Initialize SCTLR_EL1 with reset value */
msr sctlr_el1, xzr
/* Set EL1 entry point */
adr x0, at_testel
msr elr_el3, x0
/* Prepare SPSR for exception return to EL1h with interrupts masked */
mov x0, #0x3c5 /* DAIF bits and EL1h mode (5) */
msr spsr_el3, x0
isb /* Synchronization barrier */
eret /* Jump to EL1 */
setup_el2:
/* Ensure we trap if we get anything wrong */
adr x0, vector_table
msr vbar_el2, x0
/* Does the test want to be at EL2? */
cmp w11, #2
beq at_testel
/* Configure EL2 to allow transition to EL1 */
mrs x0, hcr_el2
orr x0, x0, #(1 << 31) /* RW = 1: EL1 execution state is AArch64 */
msr hcr_el2, x0
/* Initialize SCTLR_EL1 with reset value */
msr sctlr_el1, xzr
/* Set EL1 entry point */
adr x0, at_testel
msr elr_el2, x0
/* Prepare SPSR for exception return to EL1 */
mov x0, #(0x5 << 0) /* EL1h (SPx), with interrupts disabled */
msr spsr_el2, x0
/* Return to EL1 */
eret
/*
* At the target EL for the test, usually EL1. Note we still
* set everything up as if we were at EL1.
*/
at_testel:
/* Installs a table of exception vectors to catch and handle all
exceptions by terminating the process with a diagnostic. */
adr x0, vector_table
@@ -100,7 +252,7 @@ __start:
* maps RAM to the first Gb. The stage2 tables have two 2mb
* translation block entries covering a series of adjacent
* 4k pages.
*/
*/
/* Stage 1 entry: indexed by IA[38:30] */
adr x1, . /* phys address */
@@ -198,7 +350,8 @@ __start:
orr x0, x0, #(3 << 16)
msr cpacr_el1, x0
/* Setup some stack space and enter the test code.
/*
* Setup some stack space before we enter the test code.
* Assume everything except the return value is garbage when we
* return, we won't need it.
*/
@@ -233,6 +386,11 @@ __sys_outc:
ret
.data
.align 8
cmdline:
.space 128, 0
.align 12
/* Translation table
@@ -246,6 +404,10 @@ ttb_stage2:
.space 4096, 0
.align 12
system_stack:
.space 4096, 0
system_stack_end:
stack:
.space 65536, 0
stack_end: