Add number flag

2026-09-15 09:33:46 -04:00
parent a39287e793
commit d7beb7fcad
3 changed files with 157 additions and 67 deletions
@@ -0,0 +1,111 @@
+.data
+mod_buf_0:      .space 36864
+mod_buf_1:      .space 36864
+
+.section .text
+.globl cat_file, open_fd
+
+# Cat out the given file to stdout
+# @param[in] a0: ptr to null-terminated file str. 0 = stdin
+# @param[out] a0: result code.
+cat_file:
+    addi sp, sp, -32
+    sd s0, 0(sp) 
+    sd ra, 8(sp)
+    sd s1, 16(sp) # next modbuf to WRITE TO (inverse is read) 0=modbuf_0, 1=modbuf_1
+    sd s2, 24(sp) # current modbuf byte count
+
+    mv a1, a0 # since the function takes in a0, move it to a1 for syscall
+    li s1, 1
+    li s2, 0
+    
+    beqz a0, 1f
+    call open_fd
+    j 2f
+    1:
+    li s0, 0 # stdin fd
+    2:
+
+    mv s0, a1 # put fd in s0
+
+    beqz a0, .LReadFileBlock # if we don't have an error, jump to reading
+    li a0, 1
+    j .LCatFileRet
+
+    .LReadFileBlock:
+    mv a0, s0
+    la a1, mod_buf_0
+    li a2, 4096
+    li a7, 63
+    ecall
+    blez a0, .LCloseFD # if we haven't read any bytes, EOF, close FD
+    mv s2, a0
+    li s1, 1
+
+    la t1, show_ends
+    lb t1, 0(t1)
+    beqz t1, .LNoEndings
+
+    mv a1, s2 # load mod buf size to a1
+
+    beqz s1, 1f
+    la a0, mod_buf_0 # load mod_buf_0 as read buf
+    la a2, mod_buf_1 # load mod_buf_1 as write buf
+    j 2f
+    1:
+    la a0, mod_buf_1 # load mod_buf_1 as read buf
+    la a2, mod_buf_0 # load mod_buf_0 as write buf
+    2:
+
+    call add_endings
+    xori s1, s1, 1 # flip the mod buf to write to
+    mv s2, a1 # update the current byte count
+    .LNoEndings:
+
+    beqz s1, 1f 
+    la a1, mod_buf_0
+    j 2f
+    1:
+    la a1, mod_buf_1
+    2:
+
+    mv a2, s2 # load the amount of bytes read in previous step into bytes needed to write
+    li a0, 1
+    li a7, 64
+    ecall
+    j .LReadFileBlock
+    
+    .LCloseFD:
+    mv a0, s0
+    li a7, 57 # close fd
+    ecall
+
+    .LCatFileRet:
+    ld s0, 0(sp)
+    ld ra, 8(sp)
+    ld s1, 16(sp)
+    ld s2, 24(sp)
+    addi sp, sp, 32
+    ret
+
+# Open fd
+# @param[in] a0: ptr to null-terminated file str.
+# @param[out] a0: result code. (0-exists 1-doesn't exist)
+# @param[out] a1: fd.
+open_fd:
+    mv a1, a0 # since the function takes in a0, move it to a1 for syscall
+    
+    li a0, -100 # relative/absolute path
+    li a2, 0 # readonly
+    li a7, 56 # open
+    ecall
+    bltz a0, 1f # file doesn't exist
+    mv a1, a0 # move fd to a1
+    li a0, 0
+    j 2f
+
+    1:
+    li a0, 1
+
+    2:
+    ret