Date:   Sun, 7 Apr 2019 01:09:23 +0200
From:   Helge Deller <deller@gmx.de>
To:     linux-parisc@vger.kernel.org,
        James Bottomley <James.Bottomley@hansenpartnership.com>,
        John David Anglin <dave.anglin@bell.net>
Subject: [PATCH] parisc: PA-Linux requires at least 32 MB RAM
Message-ID: <20190406230923.GA20080@ls3530.dellerweb.de>
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Sender: linux-parisc-owner@vger.kernel.org
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Even a 32-bit kernel requires at least 27 MB to decompress itself, so
halt the system with a message if the system has less memory than 32 MB.

Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/arch/parisc/boot/compressed/misc.c b/arch/parisc/boot/compres=
sed/misc.c
index 2556bb181813..2d395998f524 100644
=2D-- a/arch/parisc/boot/compressed/misc.c
+++ b/arch/parisc/boot/compressed/misc.c
@@ -145,14 +145,13 @@ static int putchar(int c)

 void __noreturn error(char *x)
 {
-	puts("\n\n");
-	puts(x);
-	puts("\n\n -- System halted");
+	if (x) puts(x);
+	puts("\n -- System halted\n");
 	while (1)	/* wait forever */
 		;
 }

-static int print_hex(unsigned long num)
+static int print_num(unsigned long num, int base)
 {
 	const char hex[] =3D "0123456789abcdef";
 	char str[40];
@@ -160,12 +159,14 @@ static int print_hex(unsigned long num)

 	str[i--] =3D '\0';
 	do {
-		str[i--] =3D hex[num & 0x0f];
-		num >>=3D 4;
+		str[i--] =3D hex[num % base];
+		num =3D num / base;
 	} while (num);

-	str[i--] =3D 'x';
-	str[i] =3D '0';
+	if (base =3D=3D 16) {
+		str[i--] =3D 'x';
+		str[i] =3D '0';
+	} else i++;
 	puts(&str[i]);

 	return 0;
@@ -187,8 +188,9 @@ int printf(const char *fmt, ...)

 		if (fmt[++i] =3D=3D '%')
 			goto put;
+		print_num(va_arg(args, unsigned long),
+			fmt[i] =3D=3D 'x' ? 16:10);
 		++i;
-		print_hex(va_arg(args, unsigned long));
 	}

 	va_end(args);
@@ -327,8 +329,15 @@ unsigned long decompress_kernel(unsigned int started_=
wide,
 		free_mem_end_ptr =3D rd_start;
 #endif

-	if (free_mem_ptr >=3D free_mem_end_ptr)
-		error("Kernel too big for machine.");
+	if (free_mem_ptr >=3D free_mem_end_ptr) {
+		int free_ram;
+		free_ram =3D (free_mem_ptr >> 20) + 1;
+		if (free_ram < 32)
+			free_ram =3D 32;
+		printf("\nKernel requires at least %d MB RAM.\n",
+			free_ram);
+		error(NULL);
+	}

 #ifdef DEBUG
 	printf("\n");