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Merged
romancardenas merged 1 commit into from
Jul 3, 2025
Merged

Join global_asm macro invocations #322

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1 change: 1 addition & 0 deletions riscv-rt/CHANGELOG.md
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Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
### Fixed

- `clippy` fixes
- Merged `cfg_global_asm!` macro invocations to guarantee contiguous code generation.

## [v0.15.0] - 2025-06-10

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27 changes: 10 additions & 17 deletions riscv-rt/src/asm.rs
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Expand Up @@ -5,6 +5,12 @@ macro_rules! cfg_global_asm {
{@inner, [$($x:tt)*], } => {
global_asm!{$($x)*}
};
(@inner, [$($x:tt)*], #[cfg($meta:meta)] { $($y:tt)* } $($rest:tt)*) => {
#[cfg($meta)]
cfg_global_asm!{@inner, [$($x)*], $($y)* $($rest)*}
#[cfg(not($meta))]
cfg_global_asm!{@inner, [$($x)*], $($rest)*}
};
(@inner, [$($x:tt)*], #[cfg($meta:meta)] $asm:literal, $($rest:tt)*) => {
#[cfg($meta)]
cfg_global_asm!{@inner, [$($x)* $asm,], $($rest)*}
Expand Down Expand Up @@ -80,17 +86,14 @@ _abs_start:
la t0, abort // If hart_id > _max_hart_id, jump to abort
jr t0
1:", // only valid harts reach this point
);

// INITIALIZE GLOBAL POINTER, STACK POINTER, AND FRAME POINTER
cfg_global_asm!(
".option push
.option norelax
la gp, __global_pointer$
.option pop",
);
#[cfg(not(feature = "single-hart"))]
cfg_global_asm!(
{
"mv t2, a0
lui t0, %hi(_hart_stack_size)
add t0, t0, %lo(_hart_stack_size)",
Expand All @@ -104,17 +107,13 @@ cfg_global_asm!(
addi t2, t2, -1
bnez t2, 1b
2: ",
);
cfg_global_asm!(
}
"la t1, _stack_start",
#[cfg(not(feature = "single-hart"))]
"sub t1, t1, t0",
"andi sp, t1, -16 // align stack to 16-bytes
add s0, sp, zero",
);

// STORE A0..A2 IN THE STACK, AS THEY WILL BE NEEDED LATER BY main
cfg_global_asm!(
#[cfg(target_arch = "riscv32")]
"addi sp, sp, -4 * 4 // we must keep stack aligned to 16-bytes
sw a0, 4 * 0(sp)
Expand All @@ -125,10 +124,8 @@ cfg_global_asm!(
sd a0, 8 * 0(sp)
sd a1, 8 * 1(sp)
sd a2, 8 * 2(sp)",
);

// CALL __pre_init (IF ENABLED) AND INITIALIZE RAM
cfg_global_asm!(
#[cfg(not(feature = "single-hart"))]
// Skip RAM initialization if current hart is not the boot hart
"call _mp_hook
Expand Down Expand Up @@ -169,11 +166,10 @@ cfg_global_asm!(
bltu t0, t2, 3b",
"
4: // RAM initialized",
);

// INITIALIZE FLOATING POINT UNIT
#[cfg(any(riscvf, riscvd))]
cfg_global_asm!(
{
"
li t0, 0x4000 // bit 14 is FS most significant bit
li t2, 0x2000 // bit 13 is FS least significant bit
Expand All @@ -185,10 +181,9 @@ cfg_global_asm!(
"csrrc x0, mstatus, t0
csrrs x0, mstatus, t2",
"fscsr x0",
);
}

// SET UP INTERRUPTS, RESTORE a0..a2, AND JUMP TO MAIN RUST FUNCTION
cfg_global_asm!(
"call _setup_interrupts",
#[cfg(target_arch = "riscv32")]
"lw a0, 4 * 0(sp)
Expand All @@ -203,9 +198,7 @@ cfg_global_asm!(
"la t0, main
jr t0
.cfi_endproc",
);

cfg_global_asm!(
#[cfg(not(feature = "single-hart"))]
// Default implementation of `_mp_hook` wakes hart 0 and busy-loops all the other harts.
// Users can override this function by defining their own `_mp_hook`.
Expand Down
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