Drop print_hex.c — replaced by hex8() from hex_print.c

print_hex(uint8_t) was an early bare-metal helper doing exactly what
hex8() in the freshly-ported hex_print.c does (two-digit hex via
putchar()).  hex8() is smaller (asm cp/sbc/daa nibble trick, no LUT)
and consistent with the dec8/hex16/dec16/hex32/dec32 family.

  • Replaced print_hex() calls with hex8() in examples/banked and
    examples/bankedbg.
  • Removed libc/stdio/print_hex.c, dropped its prototype from
    sprinter.h and its entry from lib/Makefile.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

examples/banked/bank1.c

@@ -7,7 +7,7 @@ void bank1_func(int x) __banked
     (void)x;
     puts("BANK1: hello from a banked function!");
     puts("BANK1: window 3 phys page = ");
-    print_hex(_io_page_w3);     /* should be BANK1's phys page */
+    hex8(_io_page_w3);     /* should be BANK1's phys page */
     putchar('\n');
     putchar('1');
     putchar('=');

examples/banked/bank2.c

@@ -7,7 +7,7 @@ void bank2_func(int x) __banked
     (void)x;
     puts("BANK2: hello from the second bank!");
     puts("BANK2: window 3 phys page = ");
-    print_hex(_io_page_w3);     /* should be BANK2's phys page */
+    hex8(_io_page_w3);     /* should be BANK2's phys page */
     putchar('\n');
     putchar('2');
     putchar('=');

examples/banked/banked.c

@@ -13,7 +13,7 @@ extern uint8_t bank_pages[];   /* filled by crt0_banked.s */
 static void show_w3(const char *who)
 {
     puts(who);
-    print_hex(_io_page_w3);     /* current physical page mapped in window 3 */
+    hex8(_io_page_w3);     /* current physical page mapped in window 3 */
     putchar('\n');
 }
 
@@ -26,10 +26,10 @@ int main(void)
     show_w3("HOME: window 3 phys page = ");
 
     puts("HOME: bank_pages[1] (BANK1 phys) = ");
-    print_hex(bank_pages[1]);
+    hex8(bank_pages[1]);
     putchar('\n');
     puts("HOME: bank_pages[2] (BANK2 phys) = ");
-    print_hex(bank_pages[2]);
+    hex8(bank_pages[2]);
     putchar('\n');
 
     puts("HOME: calling bank1_func(42)...");

examples/bankedbg/bank1.c

@@ -7,7 +7,7 @@ void bank1_func(int x) __banked
     (void)x;
     puts("BANK1: hello from a banked function (W1)!");
     puts("BANK1: window 1 phys page = ");
-    print_hex(_io_page_w1);     /* should be BANK1's phys page */
+    hex8(_io_page_w1);     /* should be BANK1's phys page */
     putchar('\n');
     putchar('1');
     putchar('=');

examples/bankedbg/bank2.c

@@ -7,7 +7,7 @@ void bank2_func(int x) __banked
     (void)x;
     puts("BANK2: hello from the second bank (W1)!");
     puts("BANK2: window 1 phys page = ");
-    print_hex(_io_page_w1);     /* should be BANK2's phys page */
+    hex8(_io_page_w1);     /* should be BANK2's phys page */
     putchar('\n');
     putchar('2');
     putchar('=');

examples/bankedbg/bankedbg.c

@@ -24,7 +24,7 @@ extern uint8_t bank_pages[];   /* filled by crt0_banked.s */
 static void show_w1(const char *who)
 {
     puts(who);
-    print_hex(_io_page_w1);     /* current physical page mapped in window 1 */
+    hex8(_io_page_w1);     /* current physical page mapped in window 1 */
     putchar('\n');
 }
 
@@ -37,10 +37,10 @@ int main(void)
     show_w1("HOME: window 1 phys page = ");
 
     puts("HOME: bank_pages[1] (BANK1 phys) = ");
-    print_hex(bank_pages[1]);
+    hex8(bank_pages[1]);
     putchar('\n');
     puts("HOME: bank_pages[2] (BANK2 phys) = ");
-    print_hex(bank_pages[2]);
+    hex8(bank_pages[2]);
     putchar('\n');
 
     puts("HOME: calling bank1_func(42)...");

lib/Makefile

@@ -36,7 +36,7 @@ LIBC_C := \
     libc/gfx/gfx_256.c        libc/gfx/gfx_16.c \
     libc/gfx/gfx_font.c       libc/gfx/gfx_text_256.c \
     libc/gfx/gfx_text_16.c \
-    libc/stdio/getchar.c libc/stdio/print_hex.c \
+    libc/stdio/getchar.c \
     libc/stdio/putchar.c libc/stdio/puts.c libc/stdio/file.c \
     libc/stdio/hex_print.c libc/stdio/dec_print.c \
     libc/stdio/solid_helpers.c \

libc/include/sprinter.h

@@ -113,8 +113,7 @@ static inline void sprinter_page_w2(uint8_t page) { _io_page_w2 = page; }
 static inline void sprinter_page_w3(uint8_t page) { _io_page_w3 = page; }
 
 /* ---- Sprinter-specific debug helpers ------------------------------ */
-/* Print one byte as two uppercase hex digits via putchar(). */
-void print_hex(uint8_t v);
+/* Use hex8() / hex16() / hex32() from <stdio.h> for hex debug output. */
 
 #ifdef DEBUG_RT
 /*

libc/stdio/print_hex.c

@@ -1,15 +0,0 @@
-/*
- * print_hex — print a single byte as two uppercase hex digits.
- *
- * No printf yet; this is what bare-metal debug looks like in stage 3.
- */
-
-#include <stdio.h>
-#include <sprinter.h>
-
-void print_hex(uint8_t v)
-{
-    static const char digits[] = "0123456789ABCDEF";
-    putchar(digits[(v >> 4) & 0x0F]);
-    putchar(digits[v & 0x0F]);
-}