monitor: Add load command

monitor/commands/commands.asm

@@ -24,6 +24,11 @@ monitor_shell_parse_command:
     call compare_string
     ifz jmp monitor_shell_list_command
 
+    ; load
+    mov r1, monitor_shell_load_command_string
+    call compare_string
+    ifz jmp monitor_shell_load_command
+
     ; set.8
     mov r1, monitor_shell_set8_command_string
     call compare_string
@@ -53,4 +58,5 @@ monitor_shell_invalid_command_string: data.str "invalid command" data.8 10 data.
     #include "monitor/commands/help.asm"
     #include "monitor/commands/jump.asm"
     #include "monitor/commands/list.asm"
+    #include "monitor/commands/load.asm"
     #include "monitor/commands/set.asm"

monitor/commands/help.asm

@@ -15,5 +15,6 @@ monitor_shell_help_text:
     data.str "help    | display this help text" data.8 10
     data.str "jump    | jump to address $0" data.8 10
     data.str "list    | list memory contents starting at address $0" data.8 10
+    data.str "load    | load disk $0's sector $1 to buffer at address $2 of size $3 sectors" data.8 10
     data.str "set.SZ  | set [$0] to $1; equivalent to `mov.SZ [$0], $1`" data.8 10
     data.8 0

monitor/commands/load.asm

@@ -0,0 +1,49 @@
+; jump command
+
+monitor_shell_load_command_string: data.strz "load"
+
+monitor_shell_load_command:
+    call monitor_shell_parse_arguments
+
+    ; r0: pointer to disk id string
+    ; r1: pointer to source sector number string
+    ; r2: pointer to destination address string
+    ; r3: pointer to number of sectors string
+
+    push r3
+    push r2
+    push r1
+    mov r1, 16
+    call string_to_int
+    mov r10, r0
+    pop r0
+    mov r1, 16
+    call string_to_int
+    mov r11, r0
+    pop r0
+    mov r1, 16
+    call string_to_int
+    mov r12, r0
+    pop r0
+    mov r1, 16
+    call string_to_int
+    mov r13, r0
+
+    ; r10: disk id
+    ; r11: source sector number
+    ; r12: destination address
+    ; r13: number of sectors
+
+    mov r31, r13
+    cmp r31, 0
+    ifz ret
+    mov r0, r11
+    mov r1, r10
+    mov r2, r12
+monitor_shell_load_command_loop:
+    call read_sector
+    inc r0
+    add r2, 512
+    loop monitor_shell_load_command_loop
+
+    ret