krane-fb-stub/host_test.c

/*
 * Host-side test harness for the stub's parsing logic.
 *   test 1: parse the LIVE device tree (/sys/firmware/fdt — contains the
 *           /firmware/coreboot node depthcharge injects at boot) and expect
 *           the LBIO table at 0xffed9000, size 0x380 (confirmed independently
 *           via `dtc -I dtb -O dts /sys/firmware/fdt` on this unit).
 *   test 2: synthetic LBIO table exercising find_framebuffer against the
 *           verified struct lb_framebuffer layout.
 * Build: gcc -O2 -o host_test host_test.c && ./host_test
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "main.c"

static int fails;

static void check(const char *what, unsigned long long got, unsigned long long want)
{
	printf("%-40s %s (got 0x%llx, want 0x%llx)\n",
	       what, got == want ? "PASS" : "FAIL", got, want);
	if (got != want)
		fails++;
}

static void put32(u8 *p, u32 v) { memcpy(p, &v, 4); }
static void put64(u8 *p, u64 v) { memcpy(p, &v, 8); }

int main(void)
{
	/* --- test 1: live DTB ------------------------------------------------ */
	FILE *f = fopen("/sys/firmware/fdt", "rb");
	if (!f) {
		printf("no live /sys/firmware/fdt, skipping test 1\n");
	} else {
		static u8 dtb[1 << 20];
		size_t n = fread(dtb, 1, sizeof(dtb), f);
		fclose(f);
		printf("loaded live fdt: %zu bytes\n", n);

		u64 addr; u32 size;
		int rc = find_coreboot_reg(dtb, &addr, &size);
		check("find_coreboot_reg found", (unsigned long long)(rc == 0), 1);
		check("LBIO address", addr, 0xffed9000ull);
		check("LBIO size", size, 0x380);
	}

	/* --- test 2: synthetic coreboot table -------------------------------- */
	u8 table[512];
	memset(table, 0, sizeof table);
	memcpy(table, "LBIO", 4);
	put32(table + 4, 24);			/* header_bytes */
	put32(table + 20, 3);			/* table_entries */

	u8 *rec = table + 24;
	/* record 0: an unrelated tag we must skip (size 16) */
	put32(rec, 1); put32(rec + 4, 16);
	rec += 16;
	/* record 1: LB_TAG_FRAMEBUFFER */
	put32(rec, 0x12);
	put32(rec + 4, 40);			/* record size */
	put32(rec + 8, 0x80000000);		/* physical_address lo */
	put32(rec + 12, 0);			/* physical_address hi */
	put32(rec + 16, 1920);			/* x_resolution */
	put32(rec + 20, 1200);			/* y_resolution */
	put32(rec + 24, 7680);			/* bytes_per_line */
	rec[28] = 32;				/* bits_per_pixel */
	rec[29] = 16; rec[30] = 8;		/* red */
	rec[31] = 8;  rec[32] = 8;		/* green */
	rec[33] = 0;  rec[34] = 8;		/* blue */

	struct fbinfo fb;
	int rc = find_framebuffer((u64)(unsigned long)table, &fb);
	check("find_framebuffer rc", (unsigned long long)(rc == 0), 1);
	check("fb pa", fb.pa, 0x80000000ull);
	check("fb xres", fb.xres, 1920);
	check("fb yres", fb.yres, 1200);
	check("fb bpl", fb.bpl, 7680);
	check("fb bpp", fb.bpp, 32);
	check("mkcolor white", mkcolor(&fb, 1, 1, 1), 0x00ffffffull);
	check("mkcolor red",   mkcolor(&fb, 1, 0, 0), 0x00ff0000ull);
	check("mkcolor yellow", mkcolor(&fb, 1, 1, 0), 0x00ffff00ull);
	check("mkcolor green", mkcolor(&fb, 0, 1, 0), 0x0000ff00ull);
	check("mkcolor blue",  mkcolor(&fb, 0, 0, 1), 0x000000ffull);

	/* fill_screen: first and last visible pixel written, nothing past end */
	{
		static u8 fbmem[1200 * 7680 + 64];
		memset(fbmem, 0xAA, sizeof fbmem);
		struct fbinfo f2 = { .pa = (u64)(unsigned long)fbmem,
				     .xres = 1920, .yres = 1200,
				     .bpl = 7680, .bpp = 32,
				     .rpos = 16, .rsize = 8,
				     .gpos = 8, .gsize = 8,
				     .bpos = 0, .bsize = 8 };
		fill_screen(&f2, 0x00ffffff);
		u32 last = *(u32 *)(fbmem + 1199 * 7680 + 1919 * 4);
		u32 first = *(u32 *)fbmem;
		check("fill first px", first, 0x00ffffff);
		check("fill last px", last, 0x00ffffff);
		check("fill no overflow (past-end untouched)",
		      (unsigned long)fbmem[1200 * 7680 + 32], 0xAA);
	}

	/* --- test 3: device-realistic pa==0 record must be accepted ---------- */
	/* coreboot 4.14 kukui publishes physical_address = 0; depthcharge's
	 * menu renders through DRAM address 0. Regression guard for the
	 * Round-5 bug (blinking parse_fail on the real device). */
	{
		memset(table, 0, sizeof table);
		memcpy(table, "LBIO", 4);
		put32(table + 4, 24);
		put32(table + 20, 1);
		u8 *r = table + 24;
		put32(r, 0x12);
		put32(r + 4, 48);
		put32(r + 8, 0);		/* physical_address = 0 */
		put32(r + 12, 0);
		put32(r + 16, 1200);		/* x */
		put32(r + 20, 1920);		/* y */
		put32(r + 24, 4800);		/* bytes_per_line */
		r[28] = 32;			/* bpp */
		r[29] = 16; r[30] = 8;
		r[31] = 8;  r[32] = 8;
		r[33] = 0;  r[34] = 8;

		struct fbinfo fb0;
		int rc0 = find_framebuffer((u64)(unsigned long)table, &fb0);
		check("pa==0 record accepted", (unsigned long long)(rc0 == 0), 1);
		check("pa==0 fb pa stays 0", fb0.pa, 0);
		check("pa==0 xres", fb0.xres, 1200);
		check("pa==0 mkcolor red", mkcolor(&fb0, 1, 0, 0), 0x00ff0000ull);
	}

	printf(fails ? "\nFAILED: %d\n" : "\nALL PASS\n", fails);
	return fails != 0;
}