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| author | Eugen Wissner <belka@caraus.de> | 2025-04-29 23:08:46 +0200 |
|---|---|---|
| committer | Eugen Wissner <belka@caraus.de> | 2025-04-29 23:08:46 +0200 |
| commit | 23b7a1ab308442777a32c3bd123e68ad98369c42 (patch) | |
| tree | 5b2ea7e933d50a9dd150568f1aafd3bad60db073 /boot/common-boot.s | |
| parent | 9c66cec171bafaf12713efb78ac6099ef1f23020 (diff) | |
| download | elna-23b7a1ab308442777a32c3bd123e68ad98369c42.tar.gz | |
Support preserved registers as identifiers
… in expressions
Diffstat (limited to 'boot/common-boot.s')
| -rw-r--r-- | boot/common-boot.s | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/boot/common-boot.s b/boot/common-boot.s index e8eba52..e5796f1 100644 --- a/boot/common-boot.s +++ b/boot/common-boot.s @@ -1,5 +1,6 @@ .global _is_alpha, _is_digit, _is_alnum, _is_upper, _is_lower -.global _write_out, _read_file, _memcmp, _write_error, _put_char, _printi +.global _write_out, _read_file, _write_error, _put_char, _printi +.global _get, _memcmp .global _divide_by_zero_error, _exit .section .rodata @@ -187,7 +188,9 @@ _write_out: # a0 - Buffer pointer. # a1 - Buffer size. # -# Returns the result in a0. +# Sets s1 to the buffer passed in a0. +# +# Returns the amount of bytes written in a0. .type _read_file, @function _read_file: # Prologue. @@ -196,9 +199,11 @@ _read_file: sw s0, 0(sp) addi s0, sp, 8 - mv a2, a1 - mv a1, a0 + mv s1, a0 + li a0, STDIN + mv a2, a1 + mv a1, s1 li a7, SYS_READ ecall @@ -293,3 +298,11 @@ _put_char: lw s0, 8(sp) add sp, sp, 16 ret + +# a0 - Pointer to an array to get the first element. +# +# Dereferences a pointer and returns what is on the address in a0. +.type _get, @function +_get: + lw a0, (a0) + ret |