Extract "stdio" part from shell

This commit is contained in:
Virgil Dupras 2019-04-22 22:41:37 -04:00
parent 8b7faa1f02
commit 5071ee9f40
2 changed files with 76 additions and 63 deletions

View File

@ -13,9 +13,10 @@
; All numerical values in the Collapse OS shell are represented and parsed in
; hexadecimal form, without prefix or suffix.
; *** REQUIREMENTS ***
; stdio
; *** DEFINES ***
; SHELL_GETC: Macro that calls a GetC routine for tty interface
; SHELL_PUTC: Macro that calls a PutC routine for tty interface
; SHELL_IO_GETC: Macro that calls a GetC routine for I/O ("load" cmd)
; SHELL_IO_PUTC: Macro that calls a PutC routine for I/O ("save" cmd)
; SHELL_EXTRA_CMD_COUNT: Number of extra cmds to be expected after the regular
@ -45,12 +46,10 @@ SHELL_BUFSIZE .equ 0x20
; Memory address that the shell is currently "pointing at" for peek, load, call
; operations. Set with mptr.
SHELL_MEM_PTR .equ SHELL_RAMSTART
; Used to store formatted hex values just before printing it.
SHELL_HEX_FMT .equ SHELL_MEM_PTR+2
; Places where we store arguments specifiers and where resulting values are
; written to after parsing.
SHELL_CMD_ARGS .equ SHELL_HEX_FMT+2
SHELL_CMD_ARGS .equ SHELL_MEM_PTR+2
; Command buffer. We read types chars into this buffer until return is pressed
; This buffer is null-terminated and we don't keep an index around: we look
@ -77,7 +76,7 @@ shellInit:
; to it rather than call it. Saves two precious bytes in the stack.
shellLoop:
; First, let's wait until something is typed.
SHELL_GETC
STDIO_GETC
jr nz, shellLoop ; nothing typed? loop
; got it. Now, is it a CR or LF?
cp ASCII_CR
@ -86,7 +85,7 @@ shellLoop:
jr z, .do ; char is LF? do!
; Echo the received character right away so that we see what we type
SHELL_PUTC
STDIO_PUTC
; Ok, gotta add it do the buffer
; save char for later
@ -125,60 +124,6 @@ shellLoop:
.prompt:
.db "> ", 0
; print null-terminated string pointed to by HL
printstr:
push af
push hl
.loop:
ld a, (hl) ; load character to send
or a ; is it zero?
jr z, .end ; if yes, we're finished
SHELL_PUTC
inc hl
jr .loop
.end:
pop hl
pop af
ret
; print A characters from string that HL points to
printnstr:
push bc
push hl
ld b, a
.loop:
ld a, (hl) ; load character to send
SHELL_PUTC
inc hl
djnz .loop
.end:
pop hl
pop bc
ret
printcrlf:
ld a, ASCII_CR
SHELL_PUTC
ld a, ASCII_LF
SHELL_PUTC
ret
; Print the hex char in A
printHex:
push af
push hl
ld hl, SHELL_HEX_FMT
call fmtHexPair
ld a, 2
call printnstr
pop hl
pop af
ret
; Parse command (null terminated) at HL and calls it
shellParse:
push af
@ -448,7 +393,7 @@ shellPeek:
; Load the specified number of bytes (max 0xff) from IO and write them in the
; current memory pointer (which doesn't change). This gets chars from
; SHELL_IO_GETC, which can be different from SHELL_GETC. Coupled with the
; SHELL_IO_GETC, which can be different from STDIO_GETC. Coupled with the
; "blockdev" part, this allows you to dynamically select your IO source.
; Control is returned to the shell only after all bytes are read.
;
@ -475,7 +420,7 @@ shellLoad:
; Load the specified number of bytes (max 0xff) from the current memory pointer
; and write them to I/O. Memory pointer doesn't move. This puts chars to
; SHELL_IO_PUTC, which can be different from SHELL_PUTC. Coupled with the
; SHELL_IO_PUTC, which can be different from STDIO_PUTC. Coupled with the
; "blockdev" part, this allows you to dynamically select your IO source.
; Control is returned to the shell only after all bytes are written.
;

68
parts/stdio.asm Normal file
View File

@ -0,0 +1,68 @@
; stdio
;
; Allows other modules to print to "standard out", that is, the console through
; which the user is connected in a decoupled manner.
;
; *** REQUIREMENTS ***
; STDIO_GETC: a macro that follows GetC API
; STDIO_PUTC: a macro that follows GetC API
; *** VARIABLES ***
; Used to store formatted hex values just before printing it.
STDIO_HEX_FMT .equ STDIO_RAMSTART
STDIO_RAMEND .equ STDIO_HEX_FMT+2
; print null-terminated string pointed to by HL
printstr:
push af
push hl
.loop:
ld a, (hl) ; load character to send
or a ; is it zero?
jr z, .end ; if yes, we're finished
STDIO_PUTC
inc hl
jr .loop
.end:
pop hl
pop af
ret
; print A characters from string that HL points to
printnstr:
push bc
push hl
ld b, a
.loop:
ld a, (hl) ; load character to send
STDIO_PUTC
inc hl
djnz .loop
.end:
pop hl
pop bc
ret
printcrlf:
ld a, ASCII_CR
STDIO_PUTC
ld a, ASCII_LF
STDIO_PUTC
ret
; Print the hex char in A
printHex:
push af
push hl
ld hl, STDIO_HEX_FMT
call fmtHexPair
ld a, 2
call printnstr
pop hl
pop af
ret