diff --git a/assemble.sh b/assemble.sh
deleted file mode 100755
index f0598ad..0000000
--- a/assemble.sh
+++ /dev/null
@@ -1,11 +0,0 @@
-#!/bin/bash
-
-set -euxo pipefail
-
-# remove existing blobs because otherwise this will append object files to the old blobs
-rm -f bin/*.a
-
-riscv64-unknown-elf-gcc -c -mabi=ilp32 -march=rv32imac eclic-mode-hack.S -o bin/eclic-mode-hack.o
-ar crs bin/gd32vf103xx-hal.a bin/eclic-mode-hack.o
-
-rm bin/eclic-mode-hack.o
diff --git a/bin/gd32vf103xx-hal.a b/bin/gd32vf103xx-hal.a
deleted file mode 100644
index 77d3c32..0000000
Binary files a/bin/gd32vf103xx-hal.a and /dev/null differ
diff --git a/build.rs b/build.rs
deleted file mode 100644
index ed9e200..0000000
--- a/build.rs
+++ /dev/null
@@ -1,21 +0,0 @@
-use std::env;
-use std::fs;
-use std::path::PathBuf;
-
-fn main() {
-    let target = env::var("TARGET").unwrap();
-    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
-    let name = env::var("CARGO_PKG_NAME").unwrap();
-
-    if target.starts_with("riscv") {
-        fs::copy(
-            format!("bin/{}.a", name),
-            out_dir.join(format!("lib{}.a", name)),
-        ).unwrap();
-
-        println!("cargo:rustc-link-lib=static={}", name);
-        println!("cargo:rustc-link-search={}", out_dir.display());
-    }
-
-    println!("cargo:rerun-if-changed=bin/{}.a", name);
-}
diff --git a/eclic-mode-hack.S b/eclic-mode-hack.S
deleted file mode 100644
index 73efeb8..0000000
--- a/eclic-mode-hack.S
+++ /dev/null
@@ -1,345 +0,0 @@
-/*
-  The code is based on vendor provided HAL libraries.
-  Most code come from Firmware\RISCV\env_Eclipse\start.S
-*/
-
-#define STORE    sw
-#define LOAD     lw
-#define LOG_REGBYTES 2
-#define REGBYTES (1 << LOG_REGBYTES)
-
-#define CSR_MSTATUS     0x300
-#define CSR_MTVT        0x307
-#define CSR_MEPC        0x341
-#define CSR_MCAUSE      0x342
-#define CSR_MTVT2       0x7EC
-#define CSR_JALMNXTI    0x7ED
-#define CSR_PUSHMCAUSE  0x7EE
-#define CSR_PUSHMEPC    0x7EF
-#define CSR_PUSHMSUBM   0x7EB
-#define CSR_MMISC_CTL   0x7d0
-#define CSR_MSUBM       0x7c4
-
-#define MSTATUS_MIE     0x00000008
-
-.option arch, +zicsr
-
-.macro DISABLE_MIE
-  csrc CSR_MSTATUS, MSTATUS_MIE
-.endm
-
-.macro SAVE_CONTEXT
-  addi sp, sp, -20*REGBYTES
-
-  STORE x1, 0*REGBYTES(sp)
-  STORE x4, 1*REGBYTES(sp)
-  STORE x5, 2*REGBYTES(sp)
-  STORE x6, 3*REGBYTES(sp)
-  STORE x7, 4*REGBYTES(sp)
-  STORE x10, 5*REGBYTES(sp)
-  STORE x11, 6*REGBYTES(sp)
-  STORE x12, 7*REGBYTES(sp)
-  STORE x13, 8*REGBYTES(sp)
-  STORE x14, 9*REGBYTES(sp)
-  STORE x15, 10*REGBYTES(sp)
-  STORE x16, 11*REGBYTES(sp)
-  STORE x17, 12*REGBYTES(sp)
-  STORE x28, 13*REGBYTES(sp)
-  STORE x29, 14*REGBYTES(sp)
-  STORE x30, 15*REGBYTES(sp)
-  STORE x31, 16*REGBYTES(sp)
-.endm
-
-.macro RESTORE_CONTEXT
-  LOAD x1, 0*REGBYTES(sp)
-  LOAD x4, 1*REGBYTES(sp)
-  LOAD x5, 2*REGBYTES(sp)
-  LOAD x6, 3*REGBYTES(sp)
-  LOAD x7, 4*REGBYTES(sp)
-  LOAD x10, 5*REGBYTES(sp)
-  LOAD x11, 6*REGBYTES(sp)
-  LOAD x12, 7*REGBYTES(sp)
-  LOAD x13, 8*REGBYTES(sp)
-  LOAD x14, 9*REGBYTES(sp)
-  LOAD x15, 10*REGBYTES(sp)
-  LOAD x16, 11*REGBYTES(sp)
-  LOAD x17, 12*REGBYTES(sp)
-  LOAD x28, 13*REGBYTES(sp)
-  LOAD x29, 14*REGBYTES(sp)
-  LOAD x30, 15*REGBYTES(sp)
-  LOAD x31, 16*REGBYTES(sp)
-  // De-allocate the stack space
-  addi sp, sp, 20*REGBYTES
-.endm
-
-// IRQ entry point
-.section .text.irq
-.option push
-.option norelax
-.align 2
-.option pop
-.global _irq_handler
-_irq_handler:
-  SAVE_CONTEXT
-
-  // The special CSR read operation, which is actually use mcause as operand to
-  // directly store it to memory
-  csrrwi  x0, CSR_PUSHMCAUSE, 17
-  // The special CSR read operation, which is actually use mepc as operand to
-  // directly store it to memory
-  csrrwi  x0, CSR_PUSHMEPC, 18
-  // The special CSR read operation, which is actually use Msubm as operand to
-  // directly store it to memory
-  csrrwi  x0, CSR_PUSHMSUBM, 19
-
-  // The special CSR read/write operation, which is actually Claim the CLIC to
-  // find its pending highest ID, if the ID is not 0, then automatically enable
-  // the mstatus.MIE, and jump to its vector-entry-label, and update the link register.
-  csrrw ra, CSR_JALMNXTI, ra
-
-  DISABLE_MIE
-
-  LOAD x5,  19*REGBYTES(sp)
-  csrw CSR_MSUBM, x5
-  LOAD x5,  18*REGBYTES(sp)
-  csrw CSR_MEPC, x5
-  LOAD x5,  17*REGBYTES(sp)
-  csrw CSR_MCAUSE, x5
-
-  RESTORE_CONTEXT
-
-  mret
-
-.section .text.vectors, "ax"
-.option push
-.option norelax
-.align 9
-.option pop
-
-vectors:
-    .word     0
-    .word     0
-    .word     0
-    .word     INT_SFT
-    .word     0
-    .word     0
-    .word     0
-    .word     INT_TMR
-    .word     0
-    .word     0
-    .word     0
-    .word     0
-    .word     0
-    .word     0
-    .word     0
-    .word     0
-    .word     0
-    .word     INT_BWEI
-    .word     INT_PMOVI
-    .word     WWDGT
-    .word     EXTI_LVD
-    .word     TAMPER
-    .word     RTC
-    .word     FMC
-    .word     RCU
-    .word     EXTI_LINE0
-    .word     EXTI_LINE1
-    .word     EXTI_LINE2
-    .word     EXTI_LINE3
-    .word     EXTI_LINE4
-    .word     DMA0_CHANNEL0
-    .word     DMA0_CHANNEL1
-    .word     DMA0_CHANNEL2
-    .word     DMA0_CHANNEL3
-    .word     DMA0_CHANNEL4
-    .word     DMA0_CHANNEL5
-    .word     DMA0_CHANNEL6
-    .word     ADC0_1
-    .word     CAN0_TX
-    .word     CAN0_RX0
-    .word     CAN0_RX1
-    .word     CAN0_EWMC
-    .word     EXTI_LINE9_5
-    .word     TIMER0_BRK
-    .word     TIMER0_UP
-    .word     TIMER0_TRG_CMT
-    .word     TIMER0_CHANNEL
-    .word     TIMER1
-    .word     TIMER2
-    .word     TIMER3
-    .word     I2C0_EV
-    .word     I2C0_ER
-    .word     I2C1_EV
-    .word     I2C1_ER
-    .word     SPI0
-    .word     SPI1
-    .word     USART0
-    .word     USART1
-    .word     USART2
-    .word     EXTI_LINE15_10
-    .word     RTC_ALARM
-    .word     USBFS_WKUP
-    .word     0
-    .word     0
-    .word     0
-    .word     0
-    .word     0
-    .word     EXMC // not present in Reference Manual but present in vendor HAL
-    .word     0
-    .word     TIMER4
-    .word     SPI2
-    .word     UART3
-    .word     UART4
-    .word     TIMER5
-    .word     TIMER6
-    .word     DMA1_CHANNEL0
-    .word     DMA1_CHANNEL1
-    .word     DMA1_CHANNEL2
-    .word     DMA1_CHANNEL3
-    .word     DMA1_CHANNEL4
-    .word     0
-    .word     0
-    .word     CAN1_TX
-    .word     CAN1_RX0
-    .word     CAN1_RX1
-    .word     CAN1_EWMC
-    .word     USBFS
-/*
-    Trap entry point (_start_trap)
-*/
-.section .trap, "ax"
-.option push
-.option norelax
-.align 6
-.option pop
-.global _start_trap
-_start_trap:
-    addi sp, sp, -16*REGBYTES
-
-    STORE ra, 0*REGBYTES(sp)
-    STORE t0, 1*REGBYTES(sp)
-    STORE t1, 2*REGBYTES(sp)
-    STORE t2, 3*REGBYTES(sp)
-    STORE t3, 4*REGBYTES(sp)
-    STORE t4, 5*REGBYTES(sp)
-    STORE t5, 6*REGBYTES(sp)
-    STORE t6, 7*REGBYTES(sp)
-    STORE a0, 8*REGBYTES(sp)
-    STORE a1, 9*REGBYTES(sp)
-    STORE a2, 10*REGBYTES(sp)
-    STORE a3, 11*REGBYTES(sp)
-    STORE a4, 12*REGBYTES(sp)
-    STORE a5, 13*REGBYTES(sp)
-    STORE a6, 14*REGBYTES(sp)
-    STORE a7, 15*REGBYTES(sp)
-
-    add a0, sp, zero
-    jal ra, _start_trap_rust
-
-    LOAD ra, 0*REGBYTES(sp)
-    LOAD t0, 1*REGBYTES(sp)
-    LOAD t1, 2*REGBYTES(sp)
-    LOAD t2, 3*REGBYTES(sp)
-    LOAD t3, 4*REGBYTES(sp)
-    LOAD t4, 5*REGBYTES(sp)
-    LOAD t5, 6*REGBYTES(sp)
-    LOAD t6, 7*REGBYTES(sp)
-    LOAD a0, 8*REGBYTES(sp)
-    LOAD a1, 9*REGBYTES(sp)
-    LOAD a2, 10*REGBYTES(sp)
-    LOAD a3, 11*REGBYTES(sp)
-    LOAD a4, 12*REGBYTES(sp)
-    LOAD a5, 13*REGBYTES(sp)
-    LOAD a6, 14*REGBYTES(sp)
-    LOAD a7, 15*REGBYTES(sp)
-
-    addi sp, sp, 16*REGBYTES
-    mret
-.section .text
-.global _setup_interrupts
-_setup_interrupts:
-    // Set the the NMI base to share with mtvec by setting CSR_MMISC_CTL
-    li t0, 0x200
-    csrs CSR_MMISC_CTL, t0
-
-    // Set the mtvt
-    la t0, vectors
-    csrw CSR_MTVT, t0
-
-    // Set the mtvt2 and enable it
-    la t0, _irq_handler
-    csrw CSR_MTVT2, t0
-    csrs CSR_MTVT2, 0x1
-
-    // Enable ECLIC and set trap handler
-    la t0, _start_trap
-    andi t0, t0, -64
-    ori t0, t0, 3
-    csrw mtvec, t0
-
-    ret
-
-.weak INT_SFT
-.weak INT_TMR
-.weak INT_BWEI
-.weak INT_PMOVI
-.weak WWDGT
-.weak EXTI_LVD
-.weak TAMPER
-.weak RTC
-.weak FMC
-.weak RCU
-.weak EXTI_LINE0
-.weak EXTI_LINE1
-.weak EXTI_LINE2
-.weak EXTI_LINE3
-.weak EXTI_LINE4
-.weak DMA0_CHANNEL0
-.weak DMA0_CHANNEL1
-.weak DMA0_CHANNEL2
-.weak DMA0_CHANNEL3
-.weak DMA0_CHANNEL4
-.weak DMA0_CHANNEL5
-.weak DMA0_CHANNEL6
-.weak ADC0_1
-.weak CAN0_TX
-.weak CAN0_RX0
-.weak CAN0_RX1
-.weak CAN0_EWMC
-.weak EXTI_LINE9_5
-.weak TIMER0_BRK
-.weak TIMER0_UP
-.weak TIMER0_TRG_CMT
-.weak TIMER0_CHANNEL
-.weak TIMER1
-.weak TIMER2
-.weak TIMER3
-.weak I2C0_EV
-.weak I2C0_ER
-.weak I2C1_EV
-.weak I2C1_ER
-.weak SPI0
-.weak SPI1
-.weak USART0
-.weak USART1
-.weak USART2
-.weak EXTI_LINE15_10
-.weak RTC_ALARM
-.weak USBFS_WKUP
-.weak EXMC
-.weak TIMER4
-.weak SPI2
-.weak UART3
-.weak UART4
-.weak TIMER5
-.weak TIMER6
-.weak DMA1_CHANNEL0
-.weak DMA1_CHANNEL1
-.weak DMA1_CHANNEL2
-.weak DMA1_CHANNEL3
-.weak DMA1_CHANNEL4
-.weak CAN1_TX
-.weak CAN1_RX0
-.weak CAN1_RX1
-.weak CAN1_EWMC
-.weak USBFS
diff --git a/src/eclic.rs b/src/eclic.rs
index 6f73c75..853a6f1 100644
--- a/src/eclic.rs
+++ b/src/eclic.rs
@@ -1,5 +1,9 @@
 use crate::pac::{ECLIC, Interrupt};
 
+/// The code is based on vendor provided HAL libraries.
+/// Most code come from Firmware\RISCV\env_Eclipse\start.S
+pub mod mode;
+
 const EFFECTIVE_LEVEL_PRIORITY_BITS: u8 = 4;
 
 #[repr(u8)]
diff --git a/src/eclic/mode.rs b/src/eclic/mode.rs
new file mode 100644
index 0000000..443114e
--- /dev/null
+++ b/src/eclic/mode.rs
@@ -0,0 +1,264 @@
+#![allow(named_asm_labels)]
+
+use core::arch::global_asm;
+
+global_asm!(
+    ".equ LOG_REGBYTES, 2",
+    ".equ REGBYTES, 1 << LOG_REGBYTES",
+    ".equ MSTATUS_MIE, 0x00000008",
+    //
+    ".macro DISABLE_MIE",
+        "csrc mstatus, MSTATUS_MIE",
+    ".endm",
+    //
+    ".macro SAVE_CONTEXT",
+        //
+        "addi sp, sp, -20*REGBYTES",
+        //
+        "sw x1, 0*REGBYTES(sp)",
+        "sw x4, 1*REGBYTES(sp)",
+        "sw x5, 2*REGBYTES(sp)",
+        "sw x6, 3*REGBYTES(sp)",
+        "sw x7, 4*REGBYTES(sp)",
+        "sw x10, 5*REGBYTES(sp)",
+        "sw x11, 6*REGBYTES(sp)",
+        "sw x12, 7*REGBYTES(sp)",
+        "sw x13, 8*REGBYTES(sp)",
+        "sw x14, 9*REGBYTES(sp)",
+        "sw x15, 10*REGBYTES(sp)",
+        "sw x16, 11*REGBYTES(sp)",
+        "sw x17, 12*REGBYTES(sp)",
+        "sw x28, 13*REGBYTES(sp)",
+        "sw x29, 14*REGBYTES(sp)",
+        "sw x30, 15*REGBYTES(sp)",
+        "sw x31, 16*REGBYTES(sp)",
+    ".endm",
+    //
+    ".macro RESTORE_CONTEXT",
+        "lw x1, 0*REGBYTES(sp)",
+        "lw x4, 1*REGBYTES(sp)",
+        "lw x5, 2*REGBYTES(sp)",
+        "lw x6, 3*REGBYTES(sp)",
+        "lw x7, 4*REGBYTES(sp)",
+        "lw x10, 5*REGBYTES(sp)",
+        "lw x11, 6*REGBYTES(sp)",
+        "lw x12, 7*REGBYTES(sp)",
+        "lw x13, 8*REGBYTES(sp)",
+        "lw x14, 9*REGBYTES(sp)",
+        "lw x15, 10*REGBYTES(sp)",
+        "lw x16, 11*REGBYTES(sp)",
+        "lw x17, 12*REGBYTES(sp)",
+        "lw x28, 13*REGBYTES(sp)",
+        "lw x29, 14*REGBYTES(sp)",
+        "lw x30, 15*REGBYTES(sp)",
+        "lw x31, 16*REGBYTES(sp)",
+        // De-allocate the stack space
+        "addi sp, sp, 20*REGBYTES",
+    ".endm",
+    //
+    ".section .text.irq",
+    ".option push",
+    ".option norelax",
+    ".p2align 2",
+    ".option pop",
+    ".global _irq_handler",
+    "_irq_handler:",
+        "SAVE_CONTEXT",
+        //
+        // The special CSR read operation, which actually uses mcause as operand
+        // to directly store it to memory
+        "csrrwi x0, 0x7ee, 17",
+        // The special CSR read operation, which actually uses mepc as operand
+        // to directly store it to memory
+        "csrrwi x0, 0x7ef, 18",
+        // The special CSR read operation, which actually uses msubm as operand
+        // to directly store it to memory
+        "csrrwi x0, 0x7eb, 19",
+        //
+        // The special CSR read/write operation, which is actually Claim the CLIC to
+        // find its pending highest ID, if the ID is not 0, then automatically enable
+        // the mstatus.MIE, and jump to its vector-entry-label, and update the link register.
+        "csrrw ra, 0x7ed, ra",
+        //
+        "DISABLE_MIE",
+        //
+        "lw x5, 19*REGBYTES(sp)",
+        // Load x5 value into PUSHMSUBM system status register
+        "csrw 0x7eb, x5",
+        "lw x5, 18*REGBYTES(sp)",
+        "csrw mepc, x5",
+        "lw x5, 17*REGBYTES(sp)",
+        "csrw mcause, x5",
+        //
+        "RESTORE_CONTEXT",
+        //
+        "mret",
+    //
+    ".section .text.vectors, \"ax\"",
+    ".option push",
+    ".option norelax",
+    ".p2align 9",
+    ".option pop",
+    "vectors:",
+        ".word     0",
+        ".word     0",
+        ".word     0",
+        ".word     INT_SFT",
+        ".word     0",
+        ".word     0",
+        ".word     0",
+        ".word     INT_TMR",
+        ".word     0",
+        ".word     0",
+        ".word     0",
+        ".word     0",
+        ".word     0",
+        ".word     0",
+        ".word     0",
+        ".word     0",
+        ".word     0",
+        ".word     INT_BWEI",
+        ".word     INT_PMOVI",
+        ".word     WWDGT",
+        ".word     EXTI_LVD",
+        ".word     TAMPER",
+        ".word     RTC",
+        ".word     FMC",
+        ".word     RCU",
+        ".word     EXTI_LINE0",
+        ".word     EXTI_LINE1",
+        ".word     EXTI_LINE2",
+        ".word     EXTI_LINE3",
+        ".word     EXTI_LINE4",
+        ".word     DMA0_CHANNEL0",
+        ".word     DMA0_CHANNEL1",
+        ".word     DMA0_CHANNEL2",
+        ".word     DMA0_CHANNEL3",
+        ".word     DMA0_CHANNEL4",
+        ".word     DMA0_CHANNEL5",
+        ".word     DMA0_CHANNEL6",
+        ".word     ADC0_1",
+        ".word     CAN0_TX",
+        ".word     CAN0_RX0",
+        ".word     CAN0_RX1",
+        ".word     CAN0_EWMC",
+        ".word     EXTI_LINE9_5",
+        ".word     TIMER0_BRK",
+        ".word     TIMER0_UP",
+        ".word     TIMER0_TRG_CMT",
+        ".word     TIMER0_CHANNEL",
+        ".word     TIMER1",
+        ".word     TIMER2",
+        ".word     TIMER3",
+        ".word     I2C0_EV",
+        ".word     I2C0_ER",
+        ".word     I2C1_EV",
+        ".word     I2C1_ER",
+        ".word     SPI0",
+        ".word     SPI1",
+        ".word     USART0",
+        ".word     USART1",
+        ".word     USART2",
+        ".word     EXTI_LINE15_10",
+        ".word     RTC_ALARM",
+        ".word     USBFS_WKUP",
+        ".word     0",
+        ".word     0",
+        ".word     0",
+        ".word     0",
+        ".word     0",
+        ".word     EXMC", // not present in Reference Manual but present in vendor HAL
+        ".word     0",
+        ".word     TIMER4",
+        ".word     SPI2",
+        ".word     UART3",
+        ".word     UART4",
+        ".word     TIMER5",
+        ".word     TIMER6",
+        ".word     DMA1_CHANNEL0",
+        ".word     DMA1_CHANNEL1",
+        ".word     DMA1_CHANNEL2",
+        ".word     DMA1_CHANNEL3",
+        ".word     DMA1_CHANNEL4",
+        ".word     0",
+        ".word     0",
+        ".word     CAN1_TX",
+        ".word     CAN1_RX0",
+        ".word     CAN1_RX1",
+        ".word     CAN1_EWMC",
+        ".word     USBFS",
+    //
+    ".section .trap, \"ax\"",
+    ".option push",
+    ".option norelax",
+    ".p2align 6",
+    ".option pop",
+    ".global _start_trap",
+    "_start_trap:",
+        "addi sp, sp, -16*REGBYTES",
+        //
+        "sw ra, 0*REGBYTES(sp)",
+        "sw t0, 1*REGBYTES(sp)",
+        "sw t1, 2*REGBYTES(sp)",
+        "sw t2, 3*REGBYTES(sp)",
+        "sw t3, 4*REGBYTES(sp)",
+        "sw t4, 5*REGBYTES(sp)",
+        "sw t5, 6*REGBYTES(sp)",
+        "sw t6, 7*REGBYTES(sp)",
+        "sw a0, 8*REGBYTES(sp)",
+        "sw a1, 9*REGBYTES(sp)",
+        "sw a2, 10*REGBYTES(sp)",
+        "sw a3, 11*REGBYTES(sp)",
+        "sw a4, 12*REGBYTES(sp)",
+        "sw a5, 13*REGBYTES(sp)",
+        "sw a6, 14*REGBYTES(sp)",
+        "sw a7, 15*REGBYTES(sp)",
+        //
+        "add a0, sp, zero",
+        "jal ra, _start_trap_rust",
+        //
+        "lw ra, 0*REGBYTES(sp)",
+        "lw t0, 1*REGBYTES(sp)",
+        "lw t1, 2*REGBYTES(sp)",
+        "lw t2, 3*REGBYTES(sp)",
+        "lw t3, 4*REGBYTES(sp)",
+        "lw t4, 5*REGBYTES(sp)",
+        "lw t5, 6*REGBYTES(sp)",
+        "lw t6, 7*REGBYTES(sp)",
+        "lw a0, 8*REGBYTES(sp)",
+        "lw a1, 9*REGBYTES(sp)",
+        "lw a2, 10*REGBYTES(sp)",
+        "lw a3, 11*REGBYTES(sp)",
+        "lw a4, 12*REGBYTES(sp)",
+        "lw a5, 13*REGBYTES(sp)",
+        "lw a6, 14*REGBYTES(sp)",
+        "lw a7, 15*REGBYTES(sp)",
+        //
+        "addi sp, sp, 16*REGBYTES",
+        "mret",
+    //
+    ".section .text",
+    ".global _setup_interrupts",
+    "_setup_interrupts:",
+        // Set the the NMI base to share with mtvec by setting CSR_MMISC_CTL
+        "li t0, 0x200",
+        "csrs 0x7d0, t0",
+        //
+        // Set the mtvt
+        "la t0, vectors",
+        "csrw 0x307, t0",
+        //
+        // Set the mtvt2 and enable it
+        "la t0, _irq_handler",
+        "csrw 0x7ec, t0",
+        "csrs 0x7ec, 0x1",
+        //
+        // Enable ECLIC and set trap handler
+        "la t0, _start_trap",
+        "andi t0, t0, -64",
+        "ori t0, t0, 3",
+        "csrw mtvec, t0",
+        //
+        "ret",
+    options(raw),
+);