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Add an EL2 hello, world example for MPS3-AN536
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‎examples/mps3-an536/reference/el2_hello-armv8r-none-eabihf.out‎

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Hello, this is semihosting! x = 1.000, y = 2.000
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Region 0: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 1: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 2: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 3: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 4: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 5: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 6: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 7: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 8: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 9: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 10: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 11: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 12: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 13: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 14: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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Region 15: El2Region { range: 0x0..=0x3f, shareability: NonShareable, access: ReadWriteNoEL10, no_exec: false, mair: 0, enable: false }
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PANIC: PanicInfo {
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message: I am an example panic,
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location: Location {
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file: "src/bin/el2_hello.rs",
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line: 31,
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column: 5,
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},
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can_unwind: true,
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force_no_backtrace: false,
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}

‎examples/mps3-an536/src/bin/el2_hello.rs‎

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//! Semihosting hello-world for Arm Cortex-R52 running in EL2 (Hyp Mode)
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#![no_std]
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#![no_main]
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// pull in our start-up code
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use cortex_r_rt::entry;
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// pull in our library
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use mps3_an536 as _;
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use cortex_ar::register::Hactlr;
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use semihosting::println;
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/// The entry-point to the Rust application.
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///
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/// It is called by the start-up code at the bottom of this file.
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#[entry]
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fn main() -> ! {
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let x = 1.0f64;
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let y = x * 2.0;
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println!("Hello, this is semihosting! x = {:0.3}, y = {:0.3}", x, y);
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let mut mpu = unsafe { cortex_ar::pmsav8::El2Mpu::new() };
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for idx in 0..mpu.num_regions() {
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if let Some(region) = mpu.get_region(idx) {
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println!("Region {}: {:?}", idx, region);
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}
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}
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panic!("I am an example panic");
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}
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// Provide a custom `_start` function that sets us up in EL2 mode, with a
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// stack.
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//
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// Unlike the default routine, it does not initialise any other stacks, or
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// switch to EL1 mode.
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core::arch::global_asm!(
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r#"
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// Work around https://github.com/rust-lang/rust/issues/127269
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.fpu vfp3-d16
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.section .text.start
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.global _start
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.type _start, %function
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_start:
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// Set stack pointer
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ldr r0, =_stack_top
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mov sp, r0
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ldr r1, =_hyp_stack_size
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sub r0, r0, r1
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// Set the HVBAR (for EL2) to _vector_table
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ldr r1, =_vector_table
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mcr p15, 4, r1, c12, c0, 0
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// Configure HACTLR to let us enter EL1
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mrc p15, 4, r1, c1, c0, 1
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mov r2, {hactlr_bits}
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orr r1, r1, r2
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mcr p15, 4, r1, c1, c0, 1
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// Init .data and .bss
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bl _init_segments
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// Allow VFP coprocessor access
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mrc p15, 0, r0, c1, c0, 2
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orr r0, r0, #0xF00000
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mcr p15, 0, r0, c1, c0, 2
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// Enable VFP
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mov r0, #0x40000000
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vmsr fpexc, r0
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// Zero all registers before calling kmain
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mov r0, 0
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mov r1, 0
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mov r2, 0
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mov r3, 0
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mov r4, 0
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mov r5, 0
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mov r6, 0
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mov r7, 0
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mov r8, 0
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mov r9, 0
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mov r10, 0
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mov r11, 0
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mov r12, 0
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// Jump to application
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bl kmain
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// In case the application returns, loop forever
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b .
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.size _start, . - _start
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"#,
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hactlr_bits = const {
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Hactlr::new_with_raw_value(0)
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.with_cpuactlr(true)
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.with_cdbgdci(true)
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.with_flashifregionr(true)
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.with_periphpregionr(true)
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.with_qosr(true)
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.with_bustimeoutr(true)
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.with_intmonr(true)
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.with_err(true)
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.with_testr1(true)
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.raw_value()
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},
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);

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