From 93f2bba6e2373a551649db8979c1cf7b6adb5134 Mon Sep 17 00:00:00 2001
From: Chien Wong <m@xv97.com>
Date: Fri, 10 Nov 2023 19:16:42 +0800
Subject: [PATCH 1/3] Fix setting incorrect sp if single-hart

If single-hart is enabled, the sp is set to _stack_start - _hart_stack_size,
rather than _stack_start. Fix this.

Fixes: 9a02223ac3b6 ("Add feature single-hart")
Signed-off-by: Chien Wong <m@xv97.com>
---
 src/asm.rs | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/asm.rs b/src/asm.rs
index c29d918..a0af873 100644
--- a/src/asm.rs
+++ b/src/asm.rs
@@ -85,7 +85,8 @@ _abs_start:
     .option push
     .option norelax
     la gp, __global_pointer$
-    .option pop",
+    .option pop
+    // Allocate stacks",
     #[cfg(all(not(feature = "single-hart"), feature = "s-mode"))]
     "mv t2, a0 // the hartid is passed as parameter by SMODE",
     #[cfg(all(not(feature = "single-hart"), not(feature = "s-mode")))]
@@ -93,9 +94,7 @@ _abs_start:
     #[cfg(not(feature = "single-hart"))]
     "lui t0, %hi(_max_hart_id)
     add t0, t0, %lo(_max_hart_id)
-    bgtu t2, t0, abort",
-    "// Allocate stacks
-    la sp, _stack_start
+    bgtu t2, t0, abort
     lui t0, %hi(_hart_stack_size)
     add t0, t0, %lo(_hart_stack_size)",
     #[cfg(all(not(feature = "single-hart"), riscvm))]
@@ -109,9 +108,10 @@ _abs_start:
     addi t1, t1, -1
     bnez t1, 1b
 2:  ",
-    "sub sp, sp, t0
-
-    // Set frame pointer
+    "la sp, _stack_start",
+    #[cfg(not(feature = "single-hart"))]
+    "sub sp, sp, t0",
+    "// Set frame pointer
     add s0, sp, zero
 
     jal zero, _start_rust

From 13364069ace221c01991f2b2bc8a2337ab1b74ba Mon Sep 17 00:00:00 2001
From: Chien Wong <m@xv97.com>
Date: Fri, 10 Nov 2023 19:20:40 +0800
Subject: [PATCH 2/3] Add 'single-hart' changelog entry

Signed-off-by: Chien Wong <m@xv97.com>
---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c3557b3..5e022be 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - New GitHub workflow for checking invalid labels in PRs
 - New GitHub workflow for checking modifications on CHANGELOG.md
 - New GitHub workflow for checking clippy lints in PRs
+- Optional cargo feature `single-hart` for single CPU targets
 
 ### Changed
 

From 97f9b6a3c5c2542f1eb01713898e9bd05034faf9 Mon Sep 17 00:00:00 2001
From: Chien Wong <m@xv97.com>
Date: Fri, 10 Nov 2023 19:23:53 +0800
Subject: [PATCH 3/3] Update doc on single-hart

Signed-off-by: Chien Wong <m@xv97.com>
---
 src/lib.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib.rs b/src/lib.rs
index 422f3f2..54e5c01 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -327,7 +327,7 @@
 //!
 //! ## `single-hart`
 //!
-//! This feature saves a little code size by removing unnecessary stack space calculation if there is only one hart on the target.
+//! This feature saves a little code size if there is only one hart on the target.
 //!
 //! ## `s-mode`
 //!