Difference: CallingCFunction (5 vs. 6)

Revision 62020-08-08 - PeterSchmid

Line: 1 to 1

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Calling C Functions from Forth and Vice Versa

Line: 17 to 17

r5	Variable register 2	Y	DO Limit
r6	Variable register 3	Y	Top Of Stack TOS
r7	Variable register 4	Y	Data stack pointer SPS

Changed:

<
<

r8	Variable register 5	Y	TOS copy
r9	Platform register (usage defined by platform in use)	Y	SPS copy

>
>

r8	Variable register 5	Y	unused
r9	Platform register (usage defined by platform in use)	Y	unused

r10	Variable register 7	Y	unused
r11	Variable register 8	Y	unused
r12	Intra-procedure-call scratch register	N	unused	6

Line: 57 to 57

Calling Forth Words from C Functions

Changed:

<
< Data Stack Pointer SPS is in R7 and Top Of Stack TOS is in R6. R7 can't be a register variable, that's why R9 is used as a temporary storage.

>
> Data Stack Pointer SPS is in R1 and Top Of Stack TOS is in R0 (first parameter).

C function FS_include() from fs.c

calls the Forth words FS_type and FS_evaluate.

Line: 65 to 65

* @brief * Interprets the content of the file. * @param[in]

Added:

>
> * forth_stack TOS (lower word) and SPS (higher word) * @param[in]

* str filename (w/ or w/o null termination) * @param[in] * count string length * @return

Changed:

<
< * None

>
> * TOS (lower word) and SPS (higer word)

Changed:

<
< void FS_include(uint8_t *str, int count) {

>
> uint64_t FS_include(uint64_t forth_stack, uint8_t *str, int count) {

FIL fil; /* File object */ FRESULT fr; /* FatFs return code */

Added:

>
> uint64_t stack; stack = forth_stack;

memcpy(path, str, count); line[count] = 0;

Line: 83 to 88

if (fr) { // open failed strcpy(line, "Err: file not found");

Changed:

<
< FS_type((uint8_t*)line, strlen(line)); return;

>
> stack = FS_type(stack, (uint8_t*)line, strlen(line));

}

/* Read every line and interprets it */ while (f_gets(line, sizeof line, &fil)) { // line without \n

Changed:

<
< FS_evaluate((uint8_t*)line, strlen(line)-1);

>
> stack = FS_evaluate(stack, (uint8_t*)line, strlen(line)-1);

}

/* Close the file */ f_close(&fil);

Added:

>
> return stack;

}

Line: 102 to 108

@ -----------------------------------------------------------------------------
		Wortbirne Flag_visible, "include"

Changed:

<
< @ ( "filename" any -- any ) Interprets the content of the file. // void FS_include(uint8_t *str, int count)

>
> @ ( any "filename" -- any ) Interprets the content of the file. // uint64_t FS_include (uint64_t forth_stack, uint8_t *str, int count);

@ ----------------------------------------------------------------------------- include: push {lr} bl token @ ( -- c-addr len ) incl:

Changed:

<
< movs r1, tos // len -> count

>
> movs r3, tos // len -> count

drop

Changed:

<
< movs r0, tos // c-addr -> str

>
> movs r2, tos // c-addr -> str

drop

Changed:

<
< movs r9, psp // get psp movs r8, tos // get tos

>
> movs r0, tos // get tos movs r1, psp // get psp

bl FS_include

Changed:

<
< movs psp, r9 // update psp movs tos, r8 // update tos

>
> movs tos, r0 // update tos movs psp, r1 // update psp

pop {pc}

The C function FS_include() from fs.c calls the Forth word evaluate by the FS_evaluate() function.

Changed:

<
< // void FS_evaluate(uint8_t* str, int count);

>
> // uint64_t FS_evaluate(uint64_t forth_stack, uint8_t* str, int count);

.global FS_evaluate FS_evaluate: push {r4-r7, lr}

Changed:

<
< movs psp, r9 // get psp movs tos, r8 // get tos

>
> movs tos, r0 // get tos movs psp, r1 // get psp

pushdatos

Changed:

<
< movs tos, r0 // str

>
> movs tos, r2 // str

pushdatos

Changed:

<
< movs tos, r1 // count

>
> movs tos, r3 // count

bl evaluate

Changed:

<
< movs r9, psp // update psp movs r8, tos // update tos

>
> movs r0, tos // update tos movs r1, psp // update psp

pop {r4-r7, pc}

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