[feat] Support runtime linking of riscv64 relocatable files.#28
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lxyhit wants to merge 1 commit intoweizhiao:mainfrom
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[feat] Support runtime linking of riscv64 relocatable files.#28lxyhit wants to merge 1 commit intoweizhiao:mainfrom
lxyhit wants to merge 1 commit intoweizhiao:mainfrom
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weizhiao
reviewed
Feb 12, 2026
| let lo12 = final_off & 0xfff; | ||
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| let ptr = segments.get_mut_ptr::<u32>(offset); | ||
| let auipc = unsafe { ptr.read_unaligned() }; |
Owner
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指令是满足一定的对齐的，可能不用使用read_unaligned和write_unaligned？
Contributor
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riscv的c扩展会导致有的指令不满足对齐，为了性能优化可以用feature指定开不开c扩展
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好吧，那就使用read_unaligned/write_unaligned吧。
weizhiao
reviewed
Feb 12, 2026
src/arch/riscv64.rs
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| R_RISCV_ADD8 => { | ||
| let Some(sym) = helper.find_symbol(r_sym) else { | ||
| return Err(boxed_error()); | ||
| }; | ||
| let ptr = segments.get_mut_ptr::<u8>(offset); | ||
| let old = unsafe { ptr.read_unaligned() }; | ||
| let new = old.wrapping_add((sym + addend).0 as u8); | ||
| unsafe { ptr.write_unaligned(new) }; | ||
| } | ||
| // ADD16: *(u16*)P = *(u16*)P + (S + A) | ||
| R_RISCV_ADD16 => { | ||
| let Some(sym) = helper.find_symbol(r_sym) else { | ||
| return Err(boxed_error()); | ||
| }; | ||
| let ptr = segments.get_mut_ptr::<u16>(offset); | ||
| let old = unsafe { ptr.read_unaligned() }; | ||
| let new = old.wrapping_add((sym + addend).0 as u16); | ||
| unsafe { ptr.write_unaligned(new) }; | ||
| } | ||
| // ADD32: *(u32*)P = *(u32*)P + (S + A) | ||
| R_RISCV_ADD32 => { | ||
| let Some(sym) = helper.find_symbol(r_sym) else { | ||
| return Err(boxed_error()); | ||
| }; | ||
| let ptr = segments.get_mut_ptr::<u32>(offset); | ||
| let old = unsafe { ptr.read_unaligned() }; | ||
| let new = old.wrapping_add((sym + addend).0 as u32); | ||
| unsafe { ptr.write_unaligned(new) }; | ||
| } | ||
| // ADD64: *(u64*)P = *(u64*)P + (S + A) | ||
| R_RISCV_ADD64 => { | ||
| let Some(sym) = helper.find_symbol(r_sym) else { | ||
| return Err(boxed_error()); | ||
| }; | ||
| let ptr = segments.get_mut_ptr::<u64>(offset); | ||
| let old = unsafe { ptr.read_unaligned() }; | ||
| let new = old.wrapping_add((sym + addend).0 as u64); | ||
| unsafe { ptr.write_unaligned(new) }; | ||
| } | ||
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| // SUB8: *(u8*)P = *(u8*)P - (S + A) | ||
| R_RISCV_SUB8 => { | ||
| let Some(sym) = helper.find_symbol(r_sym) else { | ||
| return Err(boxed_error()); | ||
| }; | ||
| let ptr = segments.get_mut_ptr::<u8>(offset); | ||
| let old = unsafe { ptr.read_unaligned() }; | ||
| let new = old.wrapping_sub((sym + addend).0 as u8); | ||
| unsafe { ptr.write_unaligned(new) }; | ||
| } | ||
| // SUB16: *(u16*)P = *(u16*)P - (S + A) | ||
| R_RISCV_SUB16 => { | ||
| let Some(sym) = helper.find_symbol(r_sym) else { | ||
| return Err(boxed_error()); | ||
| }; | ||
| let ptr = segments.get_mut_ptr::<u16>(offset); | ||
| let old = unsafe { ptr.read_unaligned() }; | ||
| let new = old.wrapping_sub((sym + addend).0 as u16); | ||
| unsafe { ptr.write_unaligned(new) }; | ||
| } | ||
| // SUB32: *(u32*)P = *(u32*)P - (S + A) | ||
| R_RISCV_SUB32 => { | ||
| let Some(sym) = helper.find_symbol(r_sym) else { | ||
| return Err(boxed_error()); | ||
| }; | ||
| let ptr = segments.get_mut_ptr::<u32>(offset); | ||
| let old = unsafe { ptr.read_unaligned() }; | ||
| let new = old.wrapping_sub((sym + addend).0 as u32); | ||
| unsafe { ptr.write_unaligned(new) }; | ||
| } | ||
| // SUB64: *(u64*)P = *(u64*)P - (S + A) | ||
| R_RISCV_SUB64 => { | ||
| let Some(sym) = helper.find_symbol(r_sym) else { | ||
| return Err(boxed_error()); | ||
| }; | ||
| let ptr = segments.get_mut_ptr::<u64>(offset); | ||
| let old = unsafe { ptr.read_unaligned() }; | ||
| let new = old.wrapping_sub((sym + addend).0 as u64); | ||
| unsafe { ptr.write_unaligned(new) }; | ||
| } | ||
| // SUB6: 6-bit subtraction (bits 5:0) |
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weizhiao
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Feb 20, 2026
src/relocation/static.rs
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| pub(crate) struct StaticRelocation { | ||
| relocation: Box<[&'static [ElfRelType]]>, | ||
| relocator: StaticRelocator, |
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这个不要放在StaticRelocation里面，在relocate_impl方法里再进行构造。目的是用到的时侯再创建，避免让RawObject一直带着
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Related issue: #21.
Initial prototype code to support runtime linking of riscv64 relocatable files, this will be modified.